EXTERNE NATIONAL IMPLEMENTATION
SPAIN
CIEMAT
Contract JOS3-CT95-0010
FINAL REPORT
December 1997
Research funded in part by
THE EUROPEAN COMMISSION
in the framework of the
Non Nuclear Energy Programme
JOULE III
ACKNOWLEDGEMENTS
The authors would like to thank the many people who have contributed to the preparation of
this Spanish national report. We would like to thank ENCASUR for their provision of data on
coal mining, the people at the Central Nuclear de Valdecaballeros for facilitating information
on the Valdecaballeros site, Jesús Olaso and Guillermo Shaw from ENAGAS, for their data
on the Algerian gas pipeline, the Departments of Renewable Energy and of Environmental
Impact of Energy at CIEMAT, for their help with the biomass and wind fuel cycles and with
atmospheric dispersion modelling, the Spanish Ministries of Agriculture and Labour, for their
data on crops and occupational accident rates, and the Consorci pel Tractament de Residus
Solids Urbans del Maresme, for their data on the waste incineration cycle.
The authors would also like to thank all the partners of the ExternE National Implementation
Project, for their comments and helpful discussions on how to calculate and best present the
results obtained, as well as the ExternE Core Project for the methodological framework.
Finally, we would like to thank the European Commission, for the financial support of the
project from the JOULE Programme.
LIST OF CONTRIBUTORS
CIEMAT
Mikel Aróstegui
Julián Leal
Yolanda Lechón
Pedro Linares
Rosa M. Sáez
Manuel Varela
TGI
Arturo Alarcón
ICAEN
Salvador Salat
Neus Sumarroca (ENTORN)
IIT
Julio Montes (for the most part of the project, working in CIEMAT)
Lucía Muñoz
Andrés Ramos
CONTENTS
0.
EXECUTIVE SUMMARY.......................................................................................................................... 1
0.1 INTRODUCTION........................................................................................................................................... 1
0.1.1
Background and objectives.............................................................................................................. 1
0.1.2
The Spanish National Implementation............................................................................................. 2
0.2 METHODOLOGY.......................................................................................................................................... 3
0.3 OVERVIEW OF THE FUEL CYCLES ASSESSED ................................................................................................ 4
0.3.1
Coal fuel cycle ................................................................................................................................. 4
0.3.2
Natural gas fuel cycle ...................................................................................................................... 5
0.3.3
Biomass/lignites fuel cycle............................................................................................................... 5
0.3.4
Wind fuel cycle................................................................................................................................. 6
0.3.5
Waste incineration ........................................................................................................................... 6
0.4 AGGREGATION ........................................................................................................................................... 7
0.5 POLICY CASE STUDY ................................................................................................................................... 8
0.6 CONCLUSIONS ............................................................................................................................................ 9
1.
INTRODUCTION...................................................................................................................................... 11
1.1 OBJECTIVES OF THE PROJECT.................................................................................................................... 11
1.2 PUBLICATIONS FROM THE PROJECT........................................................................................................... 12
1.3 STRUCTURE OF THIS REPORT .................................................................................................................... 13
1.4 THE SPANISH NATIONAL IMPLEMENTATION ............................................................................................. 13
1.4.1
Description of the country ............................................................................................................. 13
1.4.2
Overview of the Spanish energy sector .......................................................................................... 15
1.4.3
Justification of the selection of fuel cycles..................................................................................... 17
1.4.4
Related national studies................................................................................................................. 19
2.
METHODOLOGY..................................................................................................................................... 21
2.1 APPROACHES USED FOR EXTERNALITY ANALYSIS ................................................................................... 21
2.2 GUIDING PRINCIPLES IN THE DEVELOPMENT OF THE EXTERNE METHODOLOGY ...................................... 23
2.3 DEFINING THE BOUNDARIES OF THE ANALYSIS ........................................................................................ 24
2.3.1
Stages of the fuel chain .................................................................................................................. 25
2.3.2
Location of fuel chain activities..................................................................................................... 25
2.3.3
Identification of fuel chain technologies........................................................................................ 26
2.3.4
Identification of fuel chain burdens ............................................................................................... 27
2.3.5
Identification of impacts ................................................................................................................ 27
2.3.6
Valuation criteria........................................................................................................................... 28
2.3.7
Spatial limits of the impact analysis .............................................................................................. 28
2.3.8
Temporal limits of the impact analysis .......................................................................................... 29
2.4 ANALYSIS OF IMPACT PATHWAYS ............................................................................................................ 29
2.4.1
Prioritisation of impacts ................................................................................................................ 30
2.4.2
Description of priority impact pathways ....................................................................................... 31
2.4.3
Quantification of burdens .............................................................................................................. 34
2.4.4
Description of the receiving environment...................................................................................... 35
2.4.5
Quantification of impacts............................................................................................................... 36
2.4.6
Economic valuation ....................................................................................................................... 38
2.4.7
Assessment of uncertainty .............................................................................................................. 38
2.5 PRIORITY IMPACTS ASSESSED IN THE EXTERNE PROJECT ........................................................................ 39
2.5.1
Fossil technologies ........................................................................................................................ 39
2.5.2
Nuclear technologies ..................................................................................................................... 40
2.5.3
Renewable technologies................................................................................................................. 40
2.5.4
Related issues................................................................................................................................. 41
2.6 SUMMARY ................................................................................................................................................ 41
3.
COAL FUEL CYCLE................................................................................................................................ 43
3.1 DEFINITION OF THE COAL FUEL CYCLE, TECHNOLOGY AND SITE ............................................................... 43
3.1.1
Technology description.................................................................................................................. 43
3.1.2
Site description .............................................................................................................................. 49
3.2 OVERVIEW OF BURDENS ........................................................................................................................... 57
3.2.1
Atmospheric emissions................................................................................................................... 57
3.2.2
Liquid effluents .............................................................................................................................. 57
3.2.3
Solid wastes ................................................................................................................................... 57
3.2.4
Occupational accidents.................................................................................................................. 58
3.3 SELECTION OF PRIORITY IMPACTS ............................................................................................................. 58
3.4 QUANTIFICATION OF IMPACTS AND DAMAGES .......................................................................................... 59
3.4.1
Coal extraction .............................................................................................................................. 59
3.4.2
Coal transport................................................................................................................................ 60
3.4.3
Limestone production .................................................................................................................... 60
3.4.4
Limestone transport ....................................................................................................................... 61
3.4.5
Power generation........................................................................................................................... 61
3.4.6
Waste disposal ............................................................................................................................... 62
3.5 SUMMARY AND INTERPRETATION OF RESULTS ......................................................................................... 63
4.
NATURAL GAS FUEL CYCLE............................................................................................................... 65
4.1 DEFINITION OF THE NATURAL GAS FUEL CYCLE, TECHNOLOGY AND SITE .................................................. 65
4.1.1
Technology description.................................................................................................................. 65
4.1.2
Site description .............................................................................................................................. 69
4.2 OVERVIEW OF BURDENS ........................................................................................................................... 69
4.2.1
Atmospheric emissions................................................................................................................... 69
4.2.2
Solid wastes ................................................................................................................................... 70
4.3 SELECTION OF PRIORITY IMPACTS ............................................................................................................. 70
4.4 QUANTIFICATION OF IMPACTS AND DAMAGES .......................................................................................... 71
4.4.1
Extraction ...................................................................................................................................... 71
4.4.2
Transport ....................................................................................................................................... 71
4.4.3
Power generation........................................................................................................................... 72
4.5 SUMMARY AND INTERPRETATION OF RESULTS ......................................................................................... 73
5.
BIOMASS/LIGNITES FUEL CYCLE..................................................................................................... 75
5.1 DEFINITION OF THE BIOMASS/LIGNITES FUEL CYCLE, TECHNOLOGY AND SITE ........................................... 75
5.1.1
Technology description.................................................................................................................. 75
5.1.2
Site description .............................................................................................................................. 82
5.2 OVERVIEW OF BURDENS ........................................................................................................................... 90
5.2.1
Atmospheric emissions................................................................................................................... 90
5.2.2
Liquid effluents .............................................................................................................................. 90
5.2.3
Solid wastes ................................................................................................................................... 91
5.2.4
Occupational accidents.................................................................................................................. 91
5.3 SELECTION OF PRIORITY IMPACTS ............................................................................................................. 91
5.4 QUANTIFICATION OF IMPACTS AND DAMAGES .......................................................................................... 92
5.4.1
Lignite extraction........................................................................................................................... 92
5.4.2
Fuel transport ................................................................................................................................ 93
5.4.3
Limestone extraction and transport ............................................................................................... 94
5.4.4
Power generation........................................................................................................................... 94
5.5 SUMMARY AND INTERPRETATION OF RESULTS ......................................................................................... 96
6.
WIND FUEL CYCLE ................................................................................................................................ 99
6.1
DEFINITION OF THE WIND FUEL CYCLE, TECHNOLOGY AND SITE ............................................................... 99
6.1.1
Technology description.................................................................................................................. 99
6.1.2
Site description ............................................................................................................................ 101
6.2 OVERVIEW OF BURDENS ......................................................................................................................... 102
6.3 SELECTION OF PRIORITY IMPACTS ........................................................................................................... 103
6.4 QUANTIFICATION OF IMPACTS AND DAMAGES ........................................................................................ 104
6.4.1
Turbine construction.................................................................................................................... 104
6.4.2
Turbine operation ........................................................................................................................ 104
6.5 SUMMARY AND INTERPRETATION OF RESULTS ....................................................................................... 106
7.
WASTE INCINERATION ...................................................................................................................... 109
7.1 DEFINITION OF THE WASTE INCINERATION CYCLE, TECHNOLOGY AND SITE ............................................ 109
7.1.1
Technology description................................................................................................................ 109
7.1.2
Site description ............................................................................................................................ 114
7.2 OVERVIEW OF BURDENS ......................................................................................................................... 123
7.2.1
Atmospheric emissions................................................................................................................. 123
7.3 SELECTION OF PRIORITY IMPACTS ........................................................................................................... 124
7.4 QUANTIFICATION OF IMPACTS AND DAMAGES ........................................................................................ 125
7.4.1
MSW transport............................................................................................................................. 125
7.4.2
Waste treatment ........................................................................................................................... 125
7.4.3
Ash transport ............................................................................................................................... 126
7.4.4
Impacts and damages related to waste treatment ........................................................................ 127
7.5 SUMMARY AND INTERPRETATION OF RESULTS ....................................................................................... 128
8.
AGGREGATION ..................................................................................................................................... 131
8.1
8.2
8.3
9.
DESCRIPTION OF THE NATIONAL ELECTRICITY SECTOR ........................................................................... 131
AGGREGATION METHODS ....................................................................................................................... 132
RESULTS................................................................................................................................................. 133
POLICY CASE STUDY .......................................................................................................................... 139
9.1 INTRODUCTION....................................................................................................................................... 139
9.2 POLICY CASE STUDY DESCRIPTION ......................................................................................................... 140
9.3 MODEL DESCRIPTION.............................................................................................................................. 140
9.3.1
System Description ...................................................................................................................... 142
9.3.2
Emissions modelling .................................................................................................................... 142
9.3.3
Model Formulation ...................................................................................................................... 143
9.3.4
Implementation ............................................................................................................................ 146
9.4 CASE STUDY: SPANISH POWER SYSTEM ................................................................................................. 147
9.5 EXTERNALITIES OF THE SPANISH ELECTRICAL SYSTEM .......................................................................... 148
9.5.1
Fossil fuels power units ............................................................................................................... 148
9.5.2
Nuclear units................................................................................................................................ 154
9.5.3
Hydro units .................................................................................................................................. 155
9.5.4
Other units ................................................................................................................................... 155
9.6 ANALYSIS OF THE OPERATION OF THE SPANISH POWER SYSTEM ............................................................ 155
9.7 RESULTS AND CONCLUSIONS .................................................................................................................. 157
10.
CONCLUSIONS ...................................................................................................................................... 163
11.
REFERENCES ......................................................................................................................................... 165
0. EXECUTIVE SUMMARY
0.1 Introduction
0.1.1 Background and objectives
The use of energy causes damage to a wide range of receptors, including human health,
natural ecosystems, and the built environment. Such damages are referred to as external costs,
as they are not reflected in the market price of energy. These externalities have been
traditionally ignored.
However, there is a growing interest towards the internalisation of externalities to assist policy
and decision making. Several European and international organisms have expressed their
interest in this issue, as may be seen in the 5th Environmental Action Programme, in the
White Paper on Growth, competitiveness and employment, or the White Paper on Energy, all
from the European Commission. This interest has led to the development of internationally
agreed tools for the evaluation of externalities, and to its application to different energy
sources.
Within the European Commission R&D Programme Joule II, the ExternE Project developed
and demonstrated a unified methodology for the quantification of the externalities of different
power generation technologies. Under Joule III, this project has been continued with three
distinguished major tasks: ExternE Core for the further development and updating of the
methodology, ExternE National Implementation to create an EU-wide data set and ExternETransport for the application of the ExternE methodology to energy related impacts from
transport. The current report is the result of the ExternE National implementation project for
Spain.
The objective of the ExternE National Implementation project is to establish a comprehensive
and comparable set of data on externalities of power generation for all EU member states and
Norway. The tasks include the application of the ExternE methodology to the most important
fuel cycles for each country as well as to update the already existing results; to aggregate these
site- and technology-specific results to more general figures. For countries already involved in
Joule II, these data have been applied to concrete policy questions, to indicate how these data
could feed into decision and policy making processes. Other objectives were the
dissemination of results in the different countries, and the creation of a network of scientific
institutes familiar with the ExternE methodology, data, and their application.
The National Implementation project has generated a large set of comparable and validated
results, covering more than 60 cases, for 15 countries and 11 fuel cycles. A wide range of
technologies have been analysed, including fossil fuels, nuclear and renewables. Fuel cycle
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ExternE National Implementation. Spain
analyses have been carried out, determining the environmental burdens and impacts of all
stages. Therefore, besides from the externalities estimated, the project offers a large database
of environmental aspects of the fuel cycles studied.
An aggregation exercise has also been carried out, to extend the analysis to the whole
electricity system of each of the participant countries. The exercise has proved to be very
useful, although the results must be considered in most cases as a first approach, which should
be carefully revised before being taken into consideration.
In spite of all the uncertainties related to the externalities assessment, the output of the project
might prove to be very useful for policy-making, both at the national and EU level. The results
obtained provide a good basis to start the study of the internalisation of the external costs of
energy, which has been frequently cited as one of the objectives of EU energy policy. Other
possibility is to use the results for comparative purposes. The site sensitivity of the
externalities might encourage the application of the methodology for the optimisation of site
selection processes, or for cost-benefit analysis of the introduction of cleaner technologies.
The usefulness of the application for policy making has been demonstrated through the
analysis of a wide variety of decision making issues carried out by those teams already
involved in ExternE under Joule II.
Further work is needed, however, to remove as much uncertainties as possible of the
methodology, and to improve aggregation methods for electricity systems. These
improvements are required if externality values are to be used directly for policy measures,
not only as background information.. The acceptability of these measures will depend on the
credibility of the externality values.
The current report is to be seen as part of a larger set of publications. The results of these
ExternE projects is published and made available in three different reports and publications.
The current report covers the results of the national implementation for Spain, and is
published by CIEMAT. It contains all the details of the application of the methodology to the
coal, natural gas, biomass/lignites, wind and waste incineration cycles, aggregation, and a
study of the introduction of externalities into the electrictiy dispatching system, as an
illustration of the use of these results. The methodology is detailed in a separate report,
published by the EC.
0.1.2 The Spanish National Implementation
Spain is placed at the Southwestern corner of Europe, covering the major part of the Iberian
peninsula. Its total area is some 504,000 km2, and its population is near 39 million, mainly
concentrated near Madrid, and along the coast.
The Spanish energy system is characterized by the use of low quality national coal (because of
the importance of mining as support of local economies in some areas), high dependence of
fossil fuels, a nuclear moratorium, a variable participation of hydro, the development of the
infrastructure for natural gas transport, and an important increase of cogeneration and
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Executive Summary
renewables, although this growth is not enough to reach a significant share of the energy
system.
Electricity generation in Spain is produced mainly from nuclear, hydro, and national coal. for
the next years, it is expected that gas contribution will have a significant increase, as well as
renewables. National coal use will also be increased, although with cleaner generation
technologies.
This has conditioned the selection of the fuel cycles covered in this study. These fuel cycles
have been selected according to their representativeness for the future Spanish energy system,
so that the use of results for planning purposes would be rather straightforward. Therefore, the
fuel cycles assessed are: national coal burnt with clean technology, natural gas, biomass cofired with lignites, wind, and waste incineration. This latter one, in spite of its very small
contribution to the national energy sector, has become a hot issue in Spain, due to its possible
impacts on human health, and so it was considered that the assessment of its externalities
would be very useful. The choice of “future” fuel cycles has also determined that most of the
fuel cycles assessed are based on hypothetical power plants, since the existing ones are based
mostly on “old” technologies. These existing power plants have been assessed for the
aggregation exercise.
0.2 Methodology
The methodology used for the assessment of the externalities of the fuel cycles selected has
been the one developed within the ExternE Project (EC, 1995). It is a bottom-up
methodology, with a site-specific approach, that is, it considers the effect of an additional fuel
cycle, located in a specific place.
To allow comparison to be made between different fuel cycles, it is necessary to observe the
following principles:
Transparency, to show precisely how the work was done, the uncertainty associated to the
results, and the extent to which the external costs of any fuel cycle have been fully quantified.
Consistency, with respect to the boundaries placed on the system in question, to allow valid
comparison to be made between different fuel cycles and different types of impact within a
fuel cycle.
Comprehensiveness, to consider all burdens and impacts of a fuel cycle, even though many
may be not investigated in detail. For those analysed in detail, it is important that the
assessment is not arbitrarily truncated.
These characteristics should be present along the stages of the methodology, namely: site and
technology characterization, identification of burdens and impacts, prioritization of impacts,
quantification, and economic valuation.
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ExternE National Implementation. Spain
Quantification of impacts is achieved through the damage function, or impact pathway
approach. This is a series of logical steps, which trace the impact from the activity that creates
it to the damage it produces, independently for each impact and activity considered, as
required by the marginal approach.
The underlying principle for the economic valuation is to obtain the willingness to pay of the
affected individuals to avoid a negative impact, or the willingness to accept the opposite.
Several methods are available for this, which will be adopted depending on the case.
0.3 Overview of the fuel cycles assessed
0.3.1 Coal fuel cycle
As mentioned before, one of the fuel cycles to be assessed is national coal burnt with clean
technology. The reference technology for this fuel cycle is a hypothetical 1050 MW power
plant, which would be installed in Valdecaballeros, in Southwestern Spain. This hypothetical
power plant would be based on 1990 technology, and would be equipped with ESP, FGD, and
low NOx burners. Coal would come from Puertollano coal mines, some 200 km away from the
plant site.
The major burdens identified for this fuel cycle are the atmospheric emissions of pollutants
from the mining and power generation stage, liquid effluents and solid wastes from mining
and power generation, and occupational accidents from the mining stage.
The major air pollutants are SO2, NOx,and CO2. TSP emissions are also important, specially
due to the fugitive dust released in the coal extraction stage.
When selecting the priority impacts, those considered most relevant are those caused by the
atmospheric emissions from the power generation stage on human health, materials, crops and
ecosystems, and global warming. Although TSP emissions from the mining stage are quite
large, it is expected that their impact will not be too high, since they are emitted near ground
level, and so they are quickly deposited.
Liquid effluents both from the mining and power generation are expected to have significant
effects. However, their quantification is not yet possible.
As might have been expected, the major damages of this fuel cycle are on human health, due
to the air pollutant emissions, specially SO2 and NOx and CO2. They amount to some 25
mECU/kWh (plus 4 to 141 mECU/kWh for global warming). Upstream impacts are smaller,
although the occupational accidents of the mining are also significant (2.4 mECU/kWh). The
total damages are quite high, from 33 to 172 mECU/kWh, with a best estimate of 48 to 77
mECU/kWh, what is at least of the same order of magnitude as the private generation costs.,
even though the technology used is quite clean, and the site chosen is not highly populated.
Therefore, it may be seen that even environmentally-advanced, standard technologies for coal
combustion are not clean enough, if coal quality is not good. Changes to fluidized-bed
combustion or gasification cycles are required to lower the damages to reasonable terms.
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Executive Summary
0.3.2 Natural gas fuel cycle
The technology analyzed for this fuel cycle will be a combined cycle with gas turbine. The
fuel used will be Algerian natural gas, brought by pipeline, and the power plant will have an
installed power of 624 MW. Again, this is a hypothetical power plant sited in the same place
as the coal fuel cycle, Valdecaballeros..
All stages of the fuel cycle have been assessed, except for the gas extraction in Algeria, for
which no data were available. It has to be noted that the gas fuel cycle is rather clean
compared to other fossil fuel cycles. The only major burdens are the atmospheric emissions
caused by the power generation. The burdens of the gas transport by pipeline are almost
negligible.
Of the air pollutants, the major ones are NOx and CO2. There are also some SO2 emissions,
because of the use of oil as a backup fuel. However, emissions are very small.
The major impacts of this fuel cycle, thus, are those caused by air pollutants on human health,
and also the global warming impacts.
In the end, it results that damages range from 5.1 to 60.2 mECU/kWh, with a best estimate of
11 to 22 mECU/kWh, due mainly to the global warming impacts. These damages are almost
an order of magnitude lower than those of the coal fuel cycle, for example, mainly due to the
low pollutant emission rates. The impacts of upstream stages are also quite small, in spite of
the long distance from which gas is transported. This might be explained by the good quality
of the pipeline used.
0.3.3 Biomass/lignites fuel cycle
The interest of assessing this fuel cycle is to show how the environmental advantages of
biomass (negligible sulphur content, carbon neutral) are a good possibility for burning lowquality, high-sulphur lignites, on an environmentally friendly way, while still using indigenous
energy sources.
This fuel cycle will be based on a hypothetical 20 MW circulating fluidized-bed-combustion
power plant, which would be installed near Soria, in inner Spain. Fuel contribution will be
40% of forest residues from the area, and 60% black lignites from Teruel, 200 km away.
The major burdens of this fuel cycle arise from the power generation stage, from the
atmospheric emissions (mainly SO2 and CO2) generated in it. Lignite extraction also produces
significant burdens, such as atmospheric emissions and occupational accidents. No burdens
have been taken into account from the forest residues collection, since it has been considered
that this activity would have taken place even if the fuel cycle was not implemented.
Due to the relatively low density of the fuels used, road transport is also an important burden
for this fuel cycle.
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ExternE National Implementation. Spain
The major impact expected is that caused by the atmospheric emissions on human health, and
on global warming. Regarding the latter, the CO2 fixed previously by biomass has been
substracted from the power generation emissions. Another important impact is that caused by
the washing of lignites on water quality, although it is quite difficult to assess.
The resulting damages show the advantage of co-firing biomass and lignites in an
environmentally-advanced technology, such as CFBC. In spite of the very high sulphur
content of the lignites used, both the contribution of biomass and the fluidized bed reduce
considerably SO2 damages. Total damages amount to 17 to 127 mECU/kWh, with a best
estimate of 29 to 52 mECU/kWh, which are lower, for example, than those of the coal fuel
cycle, which used better quality coal.
0.3.4 Wind fuel cycle
Wind energy is one of the most promising renewable energies in Spain. Its fuel cycle is among
the most environmentally-friendly, provided that its siting is done with caution.
The wind farm analyzed here is Cabo Vilano, a 3 MW wind farm sited near Camariñas, in
Northwestern Spain. It has 20 MADE AE/20 wind turbines. These are three-bladed, 150 kW
turbines, with stall control, asynchronous generator, and steel, cylindrical towers.
Since for this fuel cycle impacts are expected to be distributed along the entire life cycle, not
accounting for stages other than operation would lead to a large underestimation of impacts.
For example, atmospheric emissions do not appear in the operational stage, but in the
manufacturing of the turbines, and are likely to be of the same magnitude as impacts more
characteristic of the wind fuel cycle, such as noise and visual amenity.
Hence, the relevant burdens of the fuel cycle include both those coming from the farm
operation, such as noise and visual amenity, and from turbine manufacturing, such as energy
use. Their impacts are not expected to be significant. Noise, which is always identified as a
major burden of wind energy, is not so here, as the farm is sited far from population centres.
Visual impact is also reduced due to this reason. Impacts on birds, which have also been
detected sometimes, have been found to be negligible, since the resident bird species seem to
have got used to the farm.
As a result, the total damages of the wind fuel cycle are very small, around 1.8 mECU/kWh.
And most of these damages come from occupational accidents, due to the large distance
traveled by the O&M staff. Both noise and visual impacts have been estimated to be
negligible.
0.3.5 Waste incineration
The waste incineration process assessed is based on a real MSW plant located in Mataró, near
Barcelona. Residues are recycled and composted, and the refuse is burnt for electricty
production, generating some 65,000 MWh per year. The amount of residues treated yearly is
around 170,000 t.
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Executive Summary
Residues are burnt in a travelling grate, and the flue gas is cleaned to remove chloride,
sulphur, heavy metals, and particulates.
The most important burdens of the waste incineration cycle are the atmospheric emissions
generated in the power generation stage. Of important concern within these emissions are the
dioxins and furans, whose effects on human health are still in dispute. Road use is also a
relevant burden, because of the low density of the fuel used.
Therefore, the major impacts selected are those produced by atmospheric emissions. Ozone
impacts are expected to be high, because of NOx and VOC emissions, the high insolation of
the area, and its urban environment. However, no ozone dispersion model is available, so an
approximation has to be used.
The total damages amount from 26 to 147 mECU/kWh, with a best estimate of 38 to 62
mECU/kWh, mostly due to CO2, and to a lesser extent, to NOx emissions. According to the
estimations, the effects of dioxins and furans are very small. Damages per t of pollutant
emitted are rather large, due to its location, very near to a large population centre. However, it
has to be noted that this is usually the case for MSW incinerators. So the only way of reducing
damages is to reduce the emission factors, by improving the environmental performance of the
technology.
It has to be remarked that these damages are not net damages. Since MSW should be disposed
of anyway, a comparison with the damages caused by alternative disposal schemes should be
carried out.
0.4 Aggregation
Spanish electricity comes mainly from three sources: nuclear, hydro, and fossil fuels. This
causes some problems for the aggregation of the external costs of the whole electricity sector.
First, nuclear and hydro fuel cycles have not been deeply studied yet, so the values available
are not as reliable as for other fuel cycles, even less transferable to Spanish conditions.
Second, although the estimation of the damages of an individual fossil power plant is not so
complex, the addition of the damages caused by various plants poses a lot of difficulties,
because of the site-specificity of results, and the alterations produced by background pollutant
emissions.
Therefore, the simple approach proposed of extrapolating results from one power plant to the
whole electricity sector is not considered reasonable. Several fossil plants have been assessed,
then, and their results extrapolated only to the nearest plants. These results have been
calculated in terms of ECU per t of pollutant emitted, so that they are independent of fuel type
and technology. By introducing these aspects, the damages per kWh for all the fossil power
plants in Spain have been estimated.
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ExternE National Implementation. Spain
Only the generation stage has been assessed, and of it, only health damages, since they
account for more than 90% of the damages (excluding global warming), and so the figures
obtained may be considered representative of the whole fuel cycle. Since health damages are
linear with regard to pollutant exposure, no problems arise from their straight addition. Global
warming damages have been estimated separately because of the larger uncertainty associated
to them.
Damages for nuclear and hydro have been extrapolated directly from the values obtained in
other countries within the ExternE Project, and so the uncertainty lied to them should be
larger.
Because of all the problems and uncertainty sources identified, the results may only be
regarded as approximate, indicative figures. However, these figures are significant, more than
106 million Ptas per year (excluding global warming), so they should at least be kept in mind
for policy making. This is more than 1% of the Spanish GDP, or around 47% of the electricity
sector turnover in 1996.
0.5 Policy case study
The objective of the policy case study undertaken is to include the results obtained in the
aggregation exercise into an electricity network exploitation model. This model provides the
minimum variable cost for the exploitation of the Spanish electricity network, subject to
operating constraints such as generation, transmission, and national fuel consumption quotas.
The model has been adapted to enable the introduction of externalities into the final decision
process.
The damages per kWh for each power plant in the Spanish electricity network were calculated
in the aggregation exercise. These damages have been introduced in the optimization model,
and so the minimum variable social cost for the Spanish electricity system has been obtained.
Various cases have been analyzed: the current situation, the introduction of externalities (with
and without national coal quotas) and a limited introduction of externalities (considering only
the damages produced within Spain, which account for some 30% of the total damages).
Results show that, when externalities are introduced, and the social cost is minimized,
national coal would be removed from the system, because of its environmental disadvantages,
and substituted by fuel-oil and gas. However, this is only achieved if the compulsory
consumption of national coal is eliminated. If this constraint is maintained, the introduction of
externalities produces no significant effects, and so their consideration may not be
worthwhile. In fact, the removal of the constraint would produce by itself a large reduction in
social costs, without taking into account externalities for the optimization, simply by changing
national coal for imported coal.
Nevertheless, it has to be remarked that here only environmental externalities have been
assesssed. National coal and lignites have also several advantages, such as their contribution
to energy security, and their support of local economies in mining regions. Therefore, in order
8
Executive Summary
to decide whether the constraint mentioned above is justified or not, a full analysis of these
aspects should be carried out.
0.6 Conclusions
The major conclusion of this study may be that, in spite of all the limitations inherent to it,
such as uncertainty, or lack of scientific knowledge in some fields, a large set of values for the
externalities of electricity generation has been calculated, and therefore a first attempt towards
the integration of environmental aspects into energy policy may be carried out.
The values obtained, although still considered sub-totals, are already significant, and, for some
cases, high enough to affect energy policy decisions.
However, due to the limitations mentioned before, it is recommended to use the results
provided by this report only as background information. This information might be very
helpful for establishing economic incentives for pollution reduction. But results should not be
used directly until the methodology is refined.
For what results might be used directly, though, is for planning processes, where the
quantitative results are not so relevant. This is the case, for example, of the optimization of
power plants site selection, or for choosing among different energy alternatives. Another
possible use of these results is for cost-benefit analysis of environmentally-friendly
technologies. As far as the more certain external damages avoided compensate the investment
cost, the installation of these devices will be justified.
Although further research is required to refine the methodology, and thus, to produce more
precise results, removing the existing uncertainties, this report is the first comprehensive
attempt to estimate the externalities of electricity generation in Spain. Hence, it is believed
that it will contribute to a large extent to the integration of environmental aspects into energy
policy.
9
1. INTRODUCTION
Economic development of the industrialised nations of the world has been founded on
continuing growth in energy demand. The use of energy clearly provides enormous benefits
to society. However, it is also linked to numerous environmental and social problems, such as
the health effects of pollution of air, water and soil, ecological disturbance and species loss,
and landscape damage. Such damages are referred to as external costs, as they have typically
not been reflected in the market price of energy, or considered by energy planners, and
consequently have tended to be ignored. Effective control of these ‘externalities’ whilst
pursuing further growth in the use of energy services poses a serious and difficult problem.
The European Commission has expressed its intent to respond to this challenge on several
occasions; in the 5th Environmental Action Programme; the White Paper on Growth,
Competitiveness and Employment; and the White Paper on Energy.
A variety of options are available for reducing externalities, ranging from the development of
new technologies to the use of fiscal instruments, or the imposition of emission limits. The
purpose of externalities research is to quantify damages in order to allow rational decisions to
be made that weigh the benefits of actions to reduce externalities against the costs of doing so.
Within the European Commission R&D Programme Joule II, the ExternE Project developed
and demonstrated a unified methodology for the quantification of the externalities of different
power generation technologies. It was launched as the EC-US Fuel Cycles Study in 1991 as a
collaborative project with the US Department of Energy. From 1993 to 1995 it continued as
the ExternE project, involving more then 40 European institutes from 9 countries, as well as
scientists from the US. This resulted in the first comprehensive attempt to use a consistent
‘bottom-up’ methodology to evaluate the external costs associated with a wide range of
different fuel chains. The result was identified by both the European and American experts in
this field as currently the most advanced project world-wide for the evaluation of external
costs of power generation (EC/OECD/IEA, 1995).
Under the European Commission’s Joule III Programme, this project has continued with three
major tasks: ExternE Core for the further development and updating of the methodology,
ExternE National Implementation to create an EU-wide data set and ExternE-Transport for the
application of the ExternE methodology to energy related impacts from transport. The current
report is the result of the ExternE National Implementation project for Spain.
1.1 Objectives of the project
The objective of the ExternE National Implementation project is to establish a comprehensive
and comparable set of data on externalities of power generation for all EU member states and
Norway. The tasks include;
11
ExternE National Implementation. Spain
• the application of the ExternE methodology to the most important fuel chains for each
country
• updating existing results as new data become available for refinement of methods
• aggregation of site- and technology-specific results to the national level
• for countries already involved in Joule II, data have been applied to policy questions, to
indicate how these data could feed into decision and policy making processes
• dissemination of results
• creation of a network of scientific institutes familiar with the ExternE methodology and
data, and their application
• compilation of results in an EU-wide information system for the study.
The data in this report results from the application of ExternE-methodology as developed
under Joule II. However, because our understanding of the impacts of environmental burdens
on humans and nature is improving continuously, this methodology (or more precise, the
scientific inputs into the accounting framework) has been updated and further developed.
The National Implementation project has generated a large set of comparable and validated
results, covering more than 60 cases, for 15 countries and 11 fuel chains. A wide range of
generating options have been analysed, including fossil, nuclear and renewable technologies.
Analysis takes account of all stages of the fuel chain, from (e.g.) extraction of fuel to disposal
of waste material from the generating plant. In addition to the estimates of externalities made
in the study, the project also offers a large database of physical and social data on the burdens
and impacts of energy systems.
The ExternE results form the most extensive externality dataset currently available. They can
now be used to look at a range of issues, including;
• internalisation of the external costs of energy
• optimisation of site selection processes
• cost benefit analysis of pollution abatement measures
• comparative assessment of energy systems
Such applications are illustrated by the case studies presented later in this report, and in other
national implementation reports.
1.2 Publications from the project
The current report is to be seen as part of a larger set of publications, which commenced with
the series of volumes published in 1995 (European Commission, 1995a-f). A further series of
reports has been generated under the present study.
First, the current report covers the results of the national implementation for Spain, and is
published by CIEMAT. It contains all the details of the application of the methodology to the
coal, natural gas, biomass co-fired with lignites, wind fuel cycles, and waste incineration,
aggregation, and an introduction of the externalities calculated into an electricity dispatching
model as an illustration of the use of these results. Brief details of the methodology are
12
Introduction
provided in Chapter 2 of this report and the Appendices; a more detailed review is provided in
a separate report (European Commission, 1998a). A further report covers the development of
estimates of global warming damages (European Commission, 1998b). The series of National
Implementation Reports for the 15 countries involved are published in a third report
(European Commission, 1998c).
In addition, further reports are to be published on the biomass and waste fuel chains, and on
the application and further development of the ExternE methodology for the transport sector.
This information can also be accessed through the ExternE website. It is held at the Institute
for Prospective Technological Studies, and is accessible through the Internet
(http://externe.jrc.es). This website is the focal point for the latest news on the project, and
hence will provide updates on the continuation of the ExternE project.
1.3 Structure of this report
The structure of this report reflects that it is part of a wider set of publications. In order to
ease comparison of results, all ExternE National Implementation reports have the same
structure and use the same way of presentation of fuel cycles, technologies and results of the
analysis.
The common structure is especially important for the description of the methodology.
Chapter 2 describes the general framework of the selected bottom-up methodology. The
major inputs from different scientific disciplines into that framework (e.g. information on
dose-response functions) are summarised in the methodological annexes to this report and are
discussed at full length in the separate methodology publication (see above).
In order to ease readability, the main text of the chapters dealing with the application to the
different fuel cycles provide the overview of technology, fuel cycles, environmental burdens
and the related externalities. More detailed information (e.g. results for a specific type of
impact) is provided in the appendices.
1.4 The Spanish National Implementation
1.4.1 Description of the country
1.4.1.1 Geographical description
Spain is placed at the Southwestern corner of Europe, being the natural bridge between
Europe and Africa. It covers the major part of the Iberian peninsula, which it shares with
Portugal, and it also includes the Balearic and Canary Islands, as well as the African territories
of Ceuta and Melilla.
13
ExternE National Implementation. Spain
The mainland lies within the northern latitudes of 36º00’03’’ and 43º47’24’’, and the
longitudes of 9º17’56’’W and 3º19’13’’E. Altitudes range from sea level to 3,478 m (Pico
Mulhacén). The highest Spanish peak, however, is Teide, in the Canary Islands, with 3,718 m
above sea level.
The total Spanish area is around 504,000 km2. Most of the land has an average altitude
between 200 and 1000 m, existing several mountain ranges, of which the major ones are the
Pyrenees, in the North, and Sierra Nevada, in the South.
The perimeter of the mainland is 5,849 km, of which 3,904 km belong to the coastline. The
rest forms the border with France and Andorra(712 km), Portugal (1,232 km) and Gibraltar (1
km).
Three major regions may be defined within the peninsula : the inner part, which is formed by
two high plateaus, divided by the Sistema Central mountain range, the northern coast, and the
southern and eastern areas.
The inner part, or Meseta, features a continental climate, with hard winters and hot summers.
Average rainfall is around 500 mm per year, and mean temperatures range between 5 and
25ºC. Most of this area is occupied by crops (olives, grapes and cereals) and pasture land.
The northern coast has an Atlantic climate, with higher precipitations, and milder
temperatures. Land is devoted mainly to pastures.
As for the Southern and Eastern regions, their climate is Mediterranean, with warm
temperatures and little rainfall. Here the major crops are olives, citrus, and horticultural
products.
All three areas feature large extensions of natural vegetation, a large part of it characteristic of
the Peninsula. Several protected areas exist, some of which have been declared to be of
special value by international institutions, due to their high-value biodiversity.
Forests make up for some 30% of the land, half of it corresponding to timber forests, and the
rest being low forests, or Mediterranean forest. The main timber species are pine and
eucalyptus, while in natural forests other species like oak, cork oak, green oak, or chestnuts
are also predominant.
1.4.1.2 Population
The population of Spain is some 38,800,000, according to the 1991 census. Population density
is around 77 inh/km2, what is quite low compared to most European countries. Moreover,
most of this population is concentrated near Madrid and Barcelona, and along the coast, so the
real density in most parts of the country is even lower.
Population distribution was shaped in the late 60s, when migratory flows to Madrid,
Barcelona, and other industrial centres were increased. This has left a very sparsely populated
14
Introduction
rural area, specially in the inner part of the country, and quite large metropolitan areas around
Madrid, Barcelona, Valencia, Bilbao and Sevilla. Correspondingly, urban population has
increased, amounting to over three-quarters of the total population.
The population distribution is also reflected in the economic activity of the country. It is
concentrated in the tertiary sector, with some 50% of the active population. Agriculture is still
quite important, employing around 10% of the active population. Unemployment is quite
high, around 20%.
1.4.2 Overview of the Spanish energy sector
For the last years, the Spanish energy system has been characterized by the following aspects :
• poor results in the improvement of energy efficiency
• use of low quality national coal (with poor heating value, and high sulfur and ash content)
• high dependence of fossil fuels (mainly oil products)
• nuclear moratorium, which prevents the commissioning of new nuclear facilities
• low participation of hydro, due to the last years drought
• important increase of cogeneration and renewables, although this growth is not enough to
reach a significant share in the energy system
• development of the infrastructure for natural gas transport.
An important factor for understanding the Spanish energy system is the use of national coal. In
spite of its high costs, and poor quality, this use is maintained because of the importance that
mining has in some areas, being the support of the local economic activity. Although there are
plans for phasing out non-profitable mining activities, there is not yet a definitive project for
it.
Spanish primary energy consumption is based mainly on oil products,and to a lesser extent on
coal. Oil is used mainly for transport, while coal is used for electricity generation.
Table 1.Error! Unknown switch argument. Primary energy consumption in Spain (ktoe)
Coal
Oil
Natural gas
Hydro
Nuclear
Others
1991
18,848
49,367
5,511
2,348
14,484
2,516
1992
19,116
50,880
5,851
1,724
14,537
2,454
1993
18,256
50,155
5,829
2,145
14,609
2,500
1994
17,934
52,267
6,480
2,410
14,415
2,486
1995
18,581
55,294
7,504
1,982
14,449
2,544
TOTAL
95,065
96,554
95,487
97,986
102,349
15
ExternE National Implementation. Spain
Of this primary energy, the major part is imported, as Spain is scarce in energy natural
resources. Only one third of the energy supply corresponds to domestic energy production,
while the rest is imported.
As mentioned before, coal is used mainly for electricity generation, as hydro and nuclear. Oil
is used mainly for final use in transport, while natural gas is used for domestic and industrial
purposes.
Table 1.Error! Unknown switch argument. Use of primary energy (ktoe)
Coal
Oil
Natural gas Hydro
Nuclear
Electricity generation
14,266
2,541
791
2,410
14,415
Final uses
2,962
45,329
5,482
0
0
Other uses
483
4,456
207
0
0
The share of final consumption is shown in the following table.
Table 1.Error! Unknown switch argument. Final energy consumption (ktoe)
Coal
Oil products
Gas
Electricity
TOTAL
Final consumption (1995)
2,707
47,646
6,550
12,484
69,382
The final energy consumption in Spain has started to grow in the last two years, due to an
increase in transport and industrial activities. Electricity and oil consumption increased around
4% every year, while coal has decreased significantly. The largest increment corresponds to
natural gas, which is expected to double its contribution to the energy system.
The per capita electricity consumption in Spain is around 3,900 kWh/yr. In order to fulfill this
demand, a total power of 47,117 MW is installed, with a total electricity production of 167
TWh, as shown in the following tables.
Table 1.Error! Unknown switch argument. Installed electricity power in Spain in 1995 (MW)
Installed power (1995)
MW
%
Hydro
16,457
36
Fossil
20,767
45
Nuclear
7,417
16
Renewable energy
1,313
3
16
Introduction
Table 1.Error! Unknown switch argument. Electricity generation in Spain in 1995 (GWh)
Electricity generated
GWh
%
Hydro
23,968
14
Fossil
89,276
52
Nuclear
55,442
32
Renewable energy
3,968
2
As may be seen in these tables, fossil energy only contributes to 52% of the total electricity
generated, even in a year in which hydro was not very important due to the drought. For those
years where rainfall is normal, fossil electricity should go down to less than 40%.
All these facts result in the following objectives for the Spanish energy policy towards year
2,000.
• Improvement in energy efficiency
• Promotion of indigenous energy resources
• Increased share of natural gas for cogeneration, combined cycles, and repowering
• Increased share of renewable energies through promotion schemes
• No increment of nuclear power generating capacity
• Increased use of national coal. Optimization of existing plants, and introduction of cleaner
generation technologies.
• Promotion of rational use of oil, replacement by natural gas
• Liberalization of the oil, gas, and electricity markets.
1.4.3 Justification of the selection of fuel cycles
The fuel cycles assessed in this report have been selected according to two main criteria : the
need to aggregate results for the whole electricity sector, and the use of these results for
planning purposes.
According to the first criteria, already existing plants should have been selected. However,
most of them are old plants, burning fuels that are not expected to be used much in the
following years. Therefore, the achievement of both criteria was not possible.
Then, the second criterium has been used. This decision was taken based on two facts, which
may seem contradictory : on one hand, the complexity of the aggregation exercise made, in
our opinion, its results less useful, and so less prioritary, than the use of the results only for
planning purposes ; on the other hand, preliminary results might be obtained for the existing
power plants. Results for fossil fuels might be obtained with EcoSense software, and results
17
ExternE National Implementation. Spain
for nuclear might be extrapolated from other countries, due to their reduced site-specificity.
For hydro, their site-specificity is so high that the assessment of a hydro power plant would
not have helped much for the aggregation.
Considering the marginal approach proposed by the ExternE methodology, it was considered
that it was more interesting to assess those fuel cycles which were deemed more
representative of the future Spanish energy system, as results would be more precise, and its
use for planning would be rather straightforward.
Hence, the fuel cycles selected were : national coal, burnt with clean technologies, natural gas,
biomass co-fired with lignites, wind, and waste incineration. Coal and wind were assessed in
the first stage of the ExternE National Implementation.
As shown previously, national coal is expected to be used more in the following years, due to
its advantages for energy security, and for maintaining the mining industry and all its related
activities. However, clean technologies have to be used, in order to comply with the national
and international environmental standards.
Natural gas is expected to have the largest increase for electricity generation, both in new
power plants, or for repowering already existing ones. The gas pipeline built from Algeria will
ensure a reliable and large supply to most regions of Spain. One possibility that has been
mentioned, and the one we assess here, is the utilization of the infrastructure of noncompleted nuclear power plants for commissioning gas power plants. In this case, the site
chosen has been Valdecaballeros, where two nuclear groups remain uncompleted. This
location is the same chosen for siting the coal fuel cycle, which might also be an alternative
fuel for this plant.
Renewables are being strongly promoted, and so their contribution to the energy balance
should be increased significantly. Among them, the largest contributors are expected to be
biomass and wind.
The most promising biomass energy sources are forest residues and energy crops. Of these,
forest residues are the easiest to use in the near future, so these have been the ones chosen for
the study. In the fuel cycle assessed, biomass will be co-fired with lignites, as this has been
identified as an efficient way of improving the environmental performance of the latter, while
improving the energy yield of biomass.
The other renewable energy source assessed is wind. Spain is one the European countries
where wind has a larger development, with projects for installing 2,500 MW in the next years.
This is due both to the favourable wind conditions and to the economic incentives established
by the Government. The wind farm assessed is sited in Galicia, where most of the wind power
will be installed.
The last fuel cycle selected has been waste incineration. This energy source has very little
relevance for the national energy balance. However, the siting of waste incineration plants has
become a hot issue in Spain, due to their possible impacts on human health. Therefore, it was
considered that the assessment of the externalities of waste incineration would be very helpful
18
Introduction
for the current debate on them, as the results might be introduced into planning processes for
future plants.
1.4.4 Related national studies
To our knowledge, no other studies have been carried out in Spain on the assessment of the
externalities of energy. The only exception to this is a Ph.D. thesis on the assessment of the
effects of air pollution caused by a coal power plant on nearby crops (Coll, 1992).
Other related studies identified have been two studies on the assessment of the damages of air
pollutants, carried out by AED ( 1991) and Azqueta and Ferreiro (Azqueta, 1994), in
Andalucía and Asturias, respectively. However, no relationship between energy production
and air pollutants was established.
This is the same for other limited studies on the effects of noise, or for the economic valuation
of ecosystems, for which no relationship with energy production was defined.
One study which estimated the externalities of energy crops was published by CIEMAT last
year (Linares et al, 1996), although the externalities assessed referred more to the cultivation
stage than to power generation. This study followed the ExternE methodology.
Since the ExternE National Implementation project started, some other studies have been
carried out. For example, CIEMAT is applying the ExternE methodology for the assessment
of the externalities of two lignite power plants in Spain.
A study has also been undertaken to quantify the external costs of conventional electricity
compared to renewable energy sources, in order to help determine the environmental subsidies
that should be awarded to renewable energy. This study will be based on an LCA analysis, but
no results are available yet.
19
2. METHODOLOGY
2.1 Approaches Used for Externality Analysis
The ExternE Project uses the ‘impact pathway’ approach for the assessment of the external
impacts and associated costs resulting from the supply and use of energy. The analysis
proceeds sequentially through the pathway, as shown in Figure 2.1. Emissions and other types
of burden such as risk of accident are quantified and followed through to impact assessment
and valuation. The approach thus provides a logical and transparent way of quantifying
externalities.
However, this style of analysis has only recently become possible, through developments in
environmental science and economics, and improvements in computing power has. Early
externalities work used a ‘top-down’ approach (the impact pathway approach being ‘bottomup’ in comparison). Such analysis is highly aggregated, being carried out at a regional or
national level, using estimates of the total quantities of pollutants emitted or present and
estimates of the total damage that they cause. Although the work of Hohmeyer (1988) and
others advanced the debate on externalities research considerably, the style of analysis was too
simplistic for adoption for policy analysis. In particular, no account could be taken of the
dependence of damage with the location of emission, beyond minor corrections for variation
of income at the valuation stage.
An alternative approach was the ‘control cost’ method, which substitutes the cost of reducing
emissions of a pollutant (which are determined from engineering data) for the cost of damages
due to these emissions. Proponents of this approach argued that when elected representatives
decide to adopt a particular level of emissions control they express the collective ‘willingnessto-pay’ of the society that they represent to avoid the damage. However, the method is
entirely self-referencing - if the theory was correct, whatever level of pollution abatement is
agreed would by definition equal the economic optimum. Although knowledge of control
costs is an important element in formulating prescriptive regulations, presenting them as if
they were damage costs is to be avoided.
Life cycle analysis (OECD, 1992; Heijungs et al, 1992; Lindfors et al, 1995) is a flourishing
discipline whose roots go back to the net energy analyses that were popular twenty years ago.
While there are several variations, all life cycle analysis is in theory based on a careful and
holistic accounting of all energy and material flows associated with a system or process. The
approach has typically been used to compare the environmental impacts associated with
different products that perform similar functions, such as plastic and glass bottles. Restriction
of the assessment to material and energy flows means that some types of externality (such as
the fiscal externalities arising from energy security) are completely outside the scope of LCA.
21
ExternE National Implementation. Spain
EMISSIONS
(e.g. tonnes/year of SO2)
DISPERSION
INCREASE IN AMBIENT
CONCENTRATIONS
(e.g. ppb SO2 for all affected
regions)
IMPACT
IMPACT
(e.g. change in crop yield)
CONCENTRATION
COST
Figure 2.1 An illustration of the main steps of the impact pathways methodology applied to
the consequences of pollutant emissions. Each step is analysed with detailed process models.
The ExternE method has numerous links to LCA. The concept of fuel cycle or fuel chain
analysis, in which all components of a given system are analysed ‘from cradle to grave’,
22
Methodology
corresponds with the LCA framework. Hence for electric power fuel chains the analysis
undertaken within the ExternE Project covers (so far as possible); fuel extraction,
transportation and preparation of fuels and other inputs; plant construction, plant operation
(power generation), waste disposal and plant decommissioning.
There are, however, some significant differences between externalities analysis as presented in
this study and typical LCA analysis. Life cycle analyses tend not to be specific on the
calculation of impacts, if they have attempted to quantify impacts at all. For example, the
‘classification factors’ identified by Heijungs et al (1992) for each pollutant are independent
of the site of release. For air pollution these factors were calculated with the assumption of
uniform mixing in the earth's atmosphere. While this can be justified for greenhouse gases
and other pollutants with long residence times, it is unrealistic for particulate matter, NOx,
SO2 and ozone (O3). The reason for this radical approximation lies in the choice of emphasis
in LCA: accounting for all material flows, direct and induced. Since induced flows occur at
many geographically different points under a variety of different conditions, it is simply not
practicable to model the fate of all emissions. In this sense, ExternE is much more ambitious
and precise in its estimates than LCA.
A second difference is that most LCA studies have a much more stringent view on system
boundaries and do not prioritise between different impacts. The ExternE analysts have to a
large extent decided themselves if certain stages of the fuel cycle, such as plant construction
or fuel transportation, can be excluded. Such decisions are made from experience of the likely
magnitude of damages, and a knowledge of whether a given type of impact is perceived to be
serious. [Note that it is recommended to quantify damages for any impact perceived to be
serious whether or not earlier analysis has suggested that associated damages will be
negligible]. What might be referred to as analytical ‘looseness’ is a consequence of the remit
of the ExternE project, which has as a final objective quantification of the externalities of
energy systems. As such the main emphasis of the study is quite properly on the impacts that
are likely (given current knowledge) to dominate the results. Externalities assessments based
on the ExternE methodology but conducted for other purposes may need to take a more truly
holistic perspective than has been attempted here.
The analysis presented in this report places its emphasis on the quantification of impacts and
cost because people care more about impacts than emissions. The quantification of emissions
is merely a step in the analysis. From this perspective the choice between externalities
assessment and conventional LCA is a matter of accuracy; uncertainties increase the further
the analysis is continued. In general terms, however, it is our view that the fuel chain analyses
of the ExternE Project can be considered a particular example of life cycle analysis.
2.2 Guiding Principles in the Development of the ExternE Methodology
The underlying principles on which the methodology for the ExternE Project has been
developed are:
23
ExternE National Implementation. Spain
Transparency, to show precisely how results are calculated, the uncertainty associated with
the results and the extent to which the external costs of any fuel chain have been fully
quantified.
Consistency, of methodology, models and assumptions (e.g. system boundaries, exposureresponse functions and valuation of risks to life) to allow valid comparisons to be made
between different fuel chains and different types of impact within a fuel chain.
That analysis should be comprehensive, we should seek to at least identify all of the effects
that may give rise to significant externalities, even if some of these cannot be quantified in
either physical or monetary terms.
In order to comply with these principles, much of the analysis described in this report looks at
the effects of individual power projects which are closely specified with respect to:
• The technologies used;
• The location of the power generation plant;
• The location of supporting activities;
• The type of fuel used;
• The source and composition of the fuel used.
Each of these factors is important in determining the magnitude of impacts and hence
associated externalities.
2.3 Defining the Boundaries of the Analysis
The starting point for fuel chain analysis is the definition of the temporal and spatial
boundaries of the system under investigation, and the range of burdens and impacts to be
addressed. The boundaries used in the ExternE Project are very broad. This is essential in
order to ensure consistency in the application of the methodology for different fuel chains.
Certain impacts brought within these boundaries cannot be quantified at the present time, and
hence the analysis is incomplete. However, this is not a problem peculiar to this style of
analysis; it simply reflects the existence of gaps in available knowledge. Our rule here is that
no impact that is known or suspected to exist, but cannot be quantified, should be ignored for
convenience. Instead it should be retained for consideration alongside whatever analysis has
been possible. Further work is needed so that unquantified effects can be better integrated
into decision making processes.
24
Methodology
2.3.1 Stages of the fuel chain
For any project associated with electricity generation the system is centred on the generation
plant itself. However, the system boundaries should be drawn so as to account for all
potential effects of a fuel chain. The exact list of stages is clearly dependent on the fuel chain
in question, but would include activities linked to the manufacture of materials for plant,
construction, demolition and site restoration as well as power generation. Other stages may
need to be considered, such as, exploration, extraction, processing and transport of fuel, and
the generation of wastes and by-products, and their treatment prior to disposal.
In practice, a complete analysis of each stage of a fuel chain is often not necessary in order to
meet the objectives of the analysis (see below). However, the onus is on the analyst to
demonstrate that this is the case - it cannot simply be assumed. Worth noting is the fact that
variation in laws and other local conditions will lead to major differences between the
importance of different stages in different parts of the world.
A further complication arises because of the linkage between fuel chains and other activities,
upstream and downstream. For example, in theory we should account for the externalities
associated with (e.g.) the production of materials for the construction of the plant used to
make the steel that is used to make turbines, coal wagons, etc. The benefit of doing so is,
however, extremely limited. Fortunately this can be demonstrated through order-ofmagnitude calculations on emissions, without the need for detailed analysis.
The treatment of waste matter and by-products deserves special mention. Impacts associated
with waste sent for disposal are part of the system under analysis. However, impacts
associated with waste utilised elsewhere (which are here referred to not a waste but as
by-products) should be considered as part of the system to which they are transferred from the
moment that they are removed from the boundaries of the fuel chain. It is of course important
to be sure that a market exists for any such by-products. The capacity of, for example, the
building industry to utilise gypsum from flue gas desulphurisation systems is clearly finite. If
it is probable that markets for particular by-products are already saturated, the ‘by-product’
must be considered as waste instead. A further difficulty lies in the uncertainties about future
management of waste storage sites. For example, if solid residues from a power plant are
disposed in a well engineered and managed landfill there is no impact (other than land use) as
long as the landfill is correctly managed; however, for the more distant future such
management is not certain.
2.3.2 Location of fuel chain activities
One of the distinguishing features of the ExternE study is the inclusion of site dependence.
For each stage of each fuel chain we have therefore identified specific locations for the power
plant and all of the other activities drawn within the system boundaries. In some cases this
has gone so far as to identify routes for the transport of fuel to power stations. The reason for
defining our analysis to this level of detail is simply that location is important in determining
the size of impacts. There are several elements to this, the most important of which are:
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ExternE National Implementation. Spain
• Variation in technology arising from differing legal requirements (e.g. concerning the use
of pollution abatement techniques, occupational safety standards, etc.);
• Variation in fuel quality;
• Variations in atmospheric dispersion;
• Differences in the sensitivity of the human and natural environment upon which fuel chain
burdens impact.
The alternative to this would be to describe a ‘representative’ site for each activity. It was
agreed at an early stage of the study that such a concept is untenable. Also, recent
developments elsewhere, such as use of critical loads analysis in the revision of the Sulphur
Protocol within the United Nations Economic Commission for Europe’s (UN ECE)
Convention on Long Range Transboundary Air Pollution, demonstrate the importance
attached to site dependence by decision makers.
However, the selection of a particular series of sites for a particular fuel chain is not altogether
realistic, particularly in relation to upstream impacts. For example, although some coal fired
power stations use coal from the local area, an increasing number use coal imported from a
number of different countries. This has now been taken into account.
2.3.3 Identification of fuel chain technologies
The main objective of this project was to quantify the external costs of power generation
technologies built in the 1990s. For the most part it was not concerned with future
technologies that are as yet unavailable, nor with older technologies which are gradually being
decommissioned.
Over recent years an increasingly prescriptive approach has been taken to the regulation of
new power projects. The concept of Best Available Techniques (BAT), coupled with
emission limits and environmental quality standards defined by both national and international
legislation, restrict the range of alternative plant designs and rates of emission. This has made
it relatively easy to select technologies for each fuel chain on a basis that is consistent across
fuel chains. However, care is still needed to ensure that a particular set of assumptions are
valid for any given country. Across the broader ExternE National Implementation Project
particular variation has for example been found with respect to the control of NOx in different
EU Member States.
As stated above, the present report deals mainly with closely specified technology options.
Results have also been aggregated for the whole electricity generating sector, providing first
estimates of damages at the national level.
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Methodology
2.3.4 Identification of fuel chain burdens
For the purposes of this project the term ‘burden’ relates to anything that is, or could be,
capable of causing an impact of whatever type. The following broad categories of ‘burden’
have been identified:
• Solid wastes;
• Liquid wastes;
• Gaseous and particulate air pollutants;
• Risk of accidents;
• Occupational exposure to hazardous substances;
• Noise;
• Others (e.g. exposure to electro-magnetic fields, emissions of heat).
During the identification of burdens no account has been taken of the likelihood of any
particular burden actually causing an impact, whether serious or not. For example, in spite of
the concern that has been voiced in recent years there is no definitive evidence that exposure
to electro-magnetic fields associated with the transmission of electricity is capable of causing
harm. The purpose of the exercise is simply to catalogue everything to provide a basis for the
analysis of different fuel chains to be conducted in a consistent and transparent manner, and to
provide a firm basis for revision of the analysis as more information on the effects of different
burdens becomes available in the future.
The need to describe burdens comprehensively is highlighted by the fact that it is only recently
that the effects of long range transport of acidic pollutants, and the release of CFCs and other
greenhouse gases have been appreciated. Ecosystem acidification, global warming and
depletion of the ozone layer are now regarded as among the most important environmental
concerns facing the world. The possibility of other apparently innocuous burdens causing
risks to health and the environment should not be ignored.
2.3.5 Identification of impacts
The next part of the work involves identification of the potential impacts of these burdens. At
this stage it is irrelevant whether a given burden will actually cause an appreciable impact; all
potential impacts of the identified burdens should be reported. The emphasis here is on
making analysts demonstrate that certain impacts are of little or no concern, according to
current knowledge. The conclusion that the externalities associated with a particular burden
or impact, when normalised to fuel chain output, are likely to be negligible is an important
result that should not be passed over without comment. It will not inevitably follow that
action to reduce the burden is unnecessary, as the impacts associated with it may have a
serious effect on a small number of people. From a policy perspective it might imply,
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ExternE National Implementation. Spain
however, that the use of fiscal instruments might not be appropriate for dealing with the
burden efficiently.
The first series of ExternE reports (European Commission, 1995a-f) provided comprehensive
listings of burdens and impacts for most of the fuel chains considered. The tasks outlined in
this section and the previous one are therefore not as onerous as they seem, and will become
easier with the development of appropriate databases.
2.3.6 Valuation criteria
Many receptors that may be affected by fuel chain activities are valued in a number of
different ways. For example, forests are valued not just for the timber that they produce, but
also for providing recreational resources, habitats for wildlife, their interactions (direct and
indirect) with climate and the hydrological cycle, protection of buildings and people in areas
subject to avalanche, etc. Externalities analysis should include all such aspects in its
valuation. Again, the fact that a full quantitative valuation along these lines is rarely possible
is besides the point when seeking to define what a study should seek to address: the analyst
has the responsibility of gathering information on behalf of decision makers and should not
make arbitrary decisions as to what may be worthy of further debate.
2.3.7 Spatial limits of the impact analysis
The system boundary also has spatial and temporal dimensions. Both should be designed to
capture impacts as fully as possible.
This has major implications for the analysis of the effects of air pollution in particular. It
necessitates extension of the analysis to a distance of hundreds of kilometres for many air
pollutants operating at the ‘regional’ scale, such as ozone, secondary particles, and SO2. For
greenhouse gases the appropriate range for the analysis is obviously global. Consideration of
these ranges is in marked contrast to the standard procedure employed in environmental
impact assessment which considers pollutant transport over a distance of only a few
kilometres and is further restricted to primary pollutants. The importance of this issue in
externalities analysis is that in many cases in the ExternE Project it has been found that
regional effects of air pollutants like SO2, NOx and associated secondary pollutants are far
greater than effects on the local scale (for examples see European Commission, 1995c). In
some locations, for example close to large cities, this pattern is reversed, and accordingly the
framework for assessing air pollution effects developed within the EcoSense model allows
specific account to be taken of local range dispersion.
It is frequently necessary to truncate the analysis at some point, because of limits on the
availability of data. Under these circumstances it is recommended that an estimate be
provided of the extent to which the analysis has been restricted. For example, one could
quantify the proportion of emissions of a given pollutant that have been accounted for, and the
proportion left unaccounted.
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Methodology
2.3.8 Temporal limits of the impact analysis
In keeping with the previous section, impacts should be assessed over their full time course.
This clearly introduces a good deal of uncertainty for long term impacts, such as those of
global warming or high level radioactive waste disposal, as it requires a view to be taken on
the structure of future society. There are a number of facets to this, such as global population
and economic growth, technological developments, the sustainability of fossil fuel
consumption and the sensitivity of the climate system to anthropogenic emissions.
The approach adopted here is that discounting should only be applied after costs are
quantified. The application of any discount rate above zero can reduce the cost of major
events in the distant future to a negligible figure. This perhaps brings into question the logic
of a simplistic approach to discounting over time scales running far beyond the experience of
recorded history. There is clear conflict here between some of the concepts that underlie
traditional economic analysis and ideas on sustainability over timescales that are meaningful
in the context of the history of the planet. For further information, the discounting of global
warming damages is discussed further in Appendix V.
The assessment of future costs is of course not simply a discounting issue. A scenario based
approach is also necessary in some cases in order to describe the possible range of outcomes.
This is illustrated by the following examples;
• A richer world would be better placed to take action against the impacts of global warming
than a poorer one;
• The damages attributable to the nuclear fuel chain could be greatly reduced if more
effective treatments for cancer are discovered.
Despite the uncertainties involved it is informative to conduct analysis of impacts that take
effect over periods of many years. By doing so it is at least possible to gain some idea of how
important these effects might be in comparison to effects experienced over shorter time scales.
The chief methodological and ethical issues that need to be addressed can also be identified.
To ignore them would suggest that they are unlikely to be of any importance.
2.4 Analysis of Impact Pathways
Having identified the range of burdens and impacts that result from a fuel chain, and defined
the technologies under investigation, the analysis typically proceeds as follows:
• Prioritisation of impacts;
• Description of priority impact pathways;
• Quantification of burdens;
• Description of the receiving environment;
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ExternE National Implementation. Spain
• Quantification of impacts;
• Economic valuation;
• Description of uncertainties.
2.4.1 Prioritisation of impacts
It is possible to produce a list of several hundred burdens and impacts for many fuel chains
(see European Commission, 1995c, pp. 49-58). A comprehensive analysis of all of these is
clearly beyond the scope of externality analysis. In the context of this study, it is important to
be sure that the analysis covers those effects that (according to present knowledge) will
provide the greatest externalities (see the discussion on life cycle analysis in section 2.1).
Accordingly, the analysis presented here is limited, though only after due consideration of the
potential magnitude of all impacts that were identified for the fuel chains that were assessed.
It is necessary to ask whether the decision to assess only a selection of impacts in detail
reduces the value of the project as a whole. We believe that it does not, as it can be shown
that many impacts (particularly those operating locally around any given fuel chain activity)
will be negligible compared to the overall damages associated with the technology under
examination.
There are good reasons for believing that local impacts will tend to be of less importance than
regional and global effects. The first is that they tend to affect only a small number of people.
Even though it is possible that some individuals may suffer very significant damages these
will not amount to a significant effect when normalised against a fuel chain output in the order
of several Tera-Watt (1012 Watt) hours per year. It is likely that the most appropriate means
of controlling such effects is through local planning systems, which be better able than policy
developed using externalities analysis to deal flexibly with the wide range of concerns that
may exist locally. A second reason for believing that local impacts will tend to be less
significant is that it is typically easier to ascribe cause and effect for impacts effective over a
short range than for those that operate at longer ranges. Accordingly there is a longer history
of legislation to combat local effects. It is only in recent years that the international dimension
of pollution of the atmosphere and water systems has been realised, and action has started to
be taken to deal with them.
There are obvious exceptions to the assertion that in many cases local impacts are of less
importance than others;
• Within OECD states one of the most important exceptions concerns occupational disease,
and accidents that affect workers and members of the public. Given the high value
attached to human life and well-being there is clear potential for associated externalities to
be large.
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Methodology
• Other cases mainly concern renewable technologies, at least in countries in which there is a
substantial body of environmental legislation governing the design and siting of nuclear
and fossil-fired plant. For example, most concern over the development of wind farms
typically relates to visual intrusion in natural landscapes and to noise emissions.
• There is the possibility that a set of conditions - meteorology, geography, plant design,
proximity of major centres of population, etc. - can combine to create local air quality
problems.
The analysis of certain upstream impacts appears to create difficulties for the consistency of
the analysis. For example, if we treat emissions of SO2 from a power station as a priority
burden, why not include emissions of SO2 from other parts of the fuel chain, for example from
the production of the steel and concrete required for the construction of the power plant?
Calculations made in the early stages of ExternE using databases, such as GEMIS (Fritsche et
al, 1992), showed that the emissions associated with material inputs to fossil power plants are
2 or 3 orders of magnitude lower than those from the power generation stage. It is thus logical
to expect that the impacts of such emissions are trivial in comparison, and can safely be
excluded from the analysis - if they were to be included the quantified effects would be
secondary to the uncertainties of the analysis of the main source of emissions. However, this
does not hold across all fuel chains. In the reports on both the wind fuel chain (European
Commission, 1995f) and the photovoltaic fuel chain (ISET, 1995), for example, it was found
that emissions associated with the manufacture of plant are capable of causing significant
externalities, relative to the others that were quantified.
The selection of priorities partly depends on whether one wants to evaluate damages or
externalities. In quite a few cases the externalities are small in spite of significant damages.
For example, if a power plant has been in place for a long time, much of the externality
associated with visual and noise impacts will have been internalised through adjustments in
the price of housing. It has been argued that occupational health effects are also likely to be
internalised. For example, if coal miners are rational and well informed their work contracts
should offer benefits that internalise the incremental risk that they are exposed to. However,
this is a very controversial assumption, as it depends precisely upon people being both rational
and well informed and also upon the existence of perfect mobility in labour markets. For the
present time we have quantified occupational health effects in full, leaving the assessment of
the degree to which they are internalised to a later date.
It is again stressed that it would be wrong to assume that those impacts given low priority in
this study are always of so little value from the perspective of energy planning that it is never
worth considering them in the assessment of external costs. Each case has to be assessed
individually. Differences in the local human and natural environment, and legislation need to
be considered.
2.4.2 Description of priority impact pathways
Some impact pathways analysed in the present study are extremely simple in form. For
example, the construction of a wind farm will affect the appearance of a landscape, leading to
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ExternE National Implementation. Spain
a change in visual amenity. In other cases the link between ‘burden’ (defined here simply as
something that causes an ‘impact’) and monetary cost is far more complex. To clearly define
the linkages involved in such cases we have drawn a series of diagrams. One of these is
shown in Figure 2.2, illustrating the series of processes that need to be accounted for from
emission of acidifying pollutants to valuation of impacts on agricultural crops. It is clearly far
more complex than the pathway suggested by Figure 2.1.
A number of points should be made about Figure 2.2. It (and others like it) do not show what
has been carried out within the project. Instead they illustrate an ideal - what one would like
to do if there was no constraint on data availability. They can thus be used both in the
development of the methodology and also as a check once analysis has been completed, to
gain an impression of the extent to which the full externality has been quantified. This last
point is important because much of the analysis presented in this report is incomplete. This
reflects on the current state of knowledge of the impacts addressed. The analysis can easily be
extended once further data becomes available. Also, for legibility, numerous feedbacks and
interactions are not explicitly shown in the diagrammatic representation of the pathway.
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Methodology
Dry deposition
Emission
I
Transport and atmospheric chemistry
II
Contribution of dry deposition
Wet deposition
Fo lia r u p ta ke
to total acidity of system
1.
2.
3.
4.
5.
6.
7.
1. Soil acidification
2. Mobilization of heavy
metals and nutrients
Foliar necrosis
Physiological damage
Chlorosis
Pest performance
Leaching
Growth stimulation
Climate interactions
III
IV
1. Root damage
Interactions
2. Leaching from foliage
3. Nutrient loss from soil
4. Nutritional balance
V
5. Climate interactions
6. Pest performance
7. etc...
8. etc...
1. Growth
2. Biomass allocation
3. Appearance
VI
4. Death
5. Soil quality
1.
2.
3.
4.
Value of produce
Land prices
Breeding costs
Soil conditioning costs
VII
Figure 2.2 The impact pathway showing the series of linkages between emission of
acidifying pollutants and ozone precursors and valuation of impacts on agricultural systems.
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2.4.3 Quantification of burdens
The data used to quantify burdens must be both current and relevant to the situation under
analysis. Emission standards, regulation of safety in the workplace and other factors vary
significantly over time and between and within different countries. It is true that the need to
meet these demands creates difficulties for data collection. However, given that the objective
of this work is to provide as far as possible an accurate account of the environmental and
social burdens imposed by energy supply and use, these issues should not be ignored. It is
notable that data for new technologies can change rapidly following their introduction. In
addition to the inevitable refinement of technologies over time, manufacturers of novel
equipment may be cautious in their assessment of plant performance. As an example of this
latter point, NOx emission factors for combined cycle gas turbine plant currently coming on
stream in several countries are far lower than was suggested by Environmental Statements
written for the same plant less than five years ago.
All impacts associated with pollution of some kind require the quantification of emissions.
Emission rates of the ‘classical’ air pollutants (CO2, SO2, NOx, CO, volatile organic
compounds and particulate matter) are quite well known. Especially well determined is the
rate of CO2 emission for fuel using equipment; it depends only on the efficiency of the
equipment and the carbon/hydrogen ratio of the fuel - uncertainty is negligible. Emissions of
the other classical air pollutants are somewhat less certain, particularly as they can vary with
operating conditions, and maintenance routines. The sulphur content of different grades of oil
and coal can vary by an order of magnitude, and hence, likewise, will emissions unless this is
compensated for through varying the performance of abatement technologies. The general
assumption made in this study is that unless otherwise specified, the technology used is the
best available according to the regulations in the country of implementation, and that
performance will not degrade. We have sought to limit the uncertainty associated with
emissions of these pollutants by close identification of the source and quality of fuel inputs
within the study.
The situation is less clear with respect to trace pollutants such as lead and mercury, since the
content of these in fuel can vary by much more than an order of magnitude. Furthermore,
some of these pollutants are emitted in such small quantities that even their measurement is
difficult. The dirtier the fuel, the greater the uncertainty in the emission estimate. There is
also the need to account for emissions to more than one media, as pollutants may be passed to
air, water or land. The last category is the subject of major uncertainty, as waste has
historically been sent for disposal to facilities of varying quality, ranging from simple holes in
the ground to well-engineered landfills. Increasing regulation relating to the disposal of
material and management of landfills should reduce uncertainty in this area greatly for
analysis within the European Union, particularly given the concept of self-sufficiency
enshrined in Regulation 259/93 on the supervision and control of shipments of waste into, out
of and within the European Community. The same will not apply in many other parts of the
world.
The problem becomes more difficult for the upstream and downstream stages of the fuel chain
because of the variety of technologies that may be involved. Particularly important may be
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Methodology
some stages of fuel chains such as biomass, where the fuel chain is potentially so diverse that
it is possible that certain activities are escaping stringent environmental regulation.
The burdens discussed so far relate only to routine emissions. Burdens resulting from
accidents also need to be considered. These might result in emissions (e.g. of oil) or an
incremental increase in the risk of injury or death to workers or members of the public. Either
way it is normally necessary to rely upon historical data to quantify accident rates. Clearly the
data should be as recent as possible so that the rates used reflect current risks. Major
uncertainty however is bound to be present when extreme events need to be considered, such
as the disasters at Chernobyl and on the Piper Alpha oil rig in the North Sea. To some extent
it is to be expected that accident rates will fall over time, drawing on experience gained.
However, structural changes in industries, for example through privatisation or a decrease in
union representation, may reverse such a trend.
Wherever possible data should be relevant to the country where a particular fuel chain activity
takes place. Major differences in burdens may arise due to different standards covering
occupational health, extension of the distance over which fuel needs to be transported, etc.
2.4.4 Description of the receiving environment
The use of the impact pathway approach requires a detailed definition of the scenario under
analysis with respect to both time and space. This includes:
• Meteorological conditions affecting dispersion and chemistry of atmospheric pollutants;
• Location, age and health of human populations relative to the source of emissions;
• The status of ecological resources;
• The value systems of individuals.
The range of the reference environment for any impact requires expert assessment of the area
influenced by the burden under investigation. As stated above, arbitrary truncation of the
reference environment is methodologically wrong and will produce results that are incorrect.
It is to be avoided as far as possible.
Clearly the need to describe the sensitivity of the receiving environment over a vast area
(extending to the whole planet for some impacts) creates a major demand on the analyst. This
is simplified by the large scale of the present study - which has been able to draw on data held
in many different countries. Further to this it has been possible to draw on numerous
databases that are being compiled as part of other work, for example on critical loads
mapping. Databases covering the whole of Europe, describing the distribution of the key
receptors affected by SO2, NOx, NH3 and fine particles have been derived or obtained for use
in the EcoSense software developed by the study team.
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ExternE National Implementation. Spain
In order to take account of future damages, some assumption is required on the evolution of
the stock at risk. In a few cases it is reasonable to assume that conditions will remain roughly
constant, and that direct extrapolation from the present day is as good an approximation as
any. In other cases, involving for example the emission of acidifying gases or the atmospheric
concentration of greenhouse gases this assumption is untenable, and scenarios need to be
developed. Confidence in these scenarios clearly declines as they extend further into the
future.
2.4.5 Quantification of impacts
The methods used to quantify various types of impact are discussed in depth in the report on
the study methodology (European Commission, 1998). The functions and other data that we
have used are summarised at the back of this report in Appendices I (describing the EcoSense
software), II (health), III (materials), IV (ecological receptors), V (global warming effects), VI
(economic issues) and VII (uncertainty). The complexity of the analysis varies greatly
between impacts. In some cases externalities can be calculated by multiplying together as few
as 3 or 4 parameters. In others it is necessary to use a series of sophisticated models linked to
large databases.
Common to all of the analysis conducted on the impacts of pollutants emitted from fuel chains
is the need for modelling the dispersion of pollutants and the use of a dose-response function
of some kind. Again, there is much variation in the complexity of the models used (see
Appendix I). The most important pollutant transport models used within ExternE relate to
the atmospheric dispersion of pollutants. They need to account not only for the physical
transport of pollutants by the winds but also for chemical transformation. The dispersion of
pollutants that are in effect chemically stable in the region of the emission can be predicted
using Gaussian plume models. These models assume source emissions are carried in a
straight line by the wind, mixing with the surrounding air both horizontally and vertically to
produce pollutant concentrations with a normal (or Gaussian) spatial distribution. The use of
these models is typically constrained to within a distance of 100 km of the source.
Air-borne pollutant transport of course extends over much greater distances than 100 km. A
different approach is needed for assessing regional transport as chemical reactions in the
atmosphere become increasingly important. This is particularly so for the acidifying
pollutants. For this analysis we have used receptor-orientated Lagrangian trajectory models.
The outputs from the trajectory models include atmospheric concentrations and deposition of
both the emitted species and secondary pollutants formed in the atmosphere.
A major problem has so far been the lack of a regional model of ozone formation and
transport within fossil-fuel power station plumes that is applicable to the European situation.
In consequence a simplified approach has been adopted for assessment of ozone effects
(European Commission, 1998).
The term ‘dose-response’ is used somewhat loosely in much of this work, as what we are
really talking about is the response to a given exposure of a pollutant in terms of atmospheric
concentration, rather than an ingested dose. Hence the terms ‘dose-response’ and ‘exposure-
36
Methodology
response’ should be considered interchangeable. A major issue with the application of such
functions concerns the assumption that they are transferable from one context to another. For
example, some of the functions for health effects of air pollutants are still derived from studies
in the USA. Is it valid to assume that these can be used in Europe? The answer to this
question is to a certain degree unknown - there is good reason to suspect that there will be
some variation, resulting from the affluence of the affected population, the exact composition
of the cocktail of pollutants that the study group was exposed to, etc. Indeed, such variation
has been noted in the results of different epidemiological studies. However, in most cases the
view of our experts has been that transference of functions is to be preferred to ignoring
particular types of impact altogether - neither option is free from uncertainty.
Dose-response functions come in a variety of functional forms, some of which are illustrated
in Figure 2.3. They may be linear or non-linear and contain thresholds (e.g. critical loads) or
not. Those describing effects of various air pollutants on agriculture have proved to be
particularly complex, incorporating both positive and negative effects, because of the potential
for certain pollutants, e.g. those containing sulphur and nitrogen, to act as fertilisers.
Non-linear
Response
Non-linear
fertilisation
Linear, no
threshold
Linear, with
threshold
Dose
Figure 2.3 A variety of possible forms for dose-response functions.
Ideally these functions and other models are derived from studies that are epidemiological assessing the effects of pollutants on real populations of people, crops, etc. This type of work
has the advantage of studying response under realistic conditions. However, results are much
more difficult to interpret than when working under laboratory conditions, where the
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ExternE National Implementation. Spain
environment can be closely controlled. Although laboratory studies provide invaluable data
on response mechanisms, they often suffer from the need to expose study populations to
extremely high levels of pollutants, often significantly greater than they would be exposed to
in the field. Extrapolation to lower, more realistic levels may introduce significant
uncertainties, particularly in cases where there is reason to suspect that a threshold may exist.
The description and implementation of exposure-response relationships is fundamental to the
entire ExternE Project. Much of the report on methodology (European Commission, 1998) is,
accordingly, devoted to assessment of the availability and reliability of these functions.
2.4.6 Economic valuation
The rationale and procedures underlying the economic valuation applied within the ExternE
Project are discussed in Appendix VI and in more detail in the methodology report (European
Commission, 1998). The approach followed is based on the quantification of individual
‘willingness to pay’ (WTP) for environmental benefit.
A limited number of goods of interest to this study - crops, timber, building materials, etc. are directly marketed, and for these valuation data are easy to obtain. However, many of the
more important goods of concern are not directly marketed, including human health,
ecological systems and non-timber benefits of forests. Alternative techniques have been
developed for valuation of such goods, the main ones being hedonic pricing, travel cost
methods and contingent valuation (Appendix VI). All of these techniques involve
uncertainties, though they have been considerably refined over the years.
The base year for the valuation described in this report is 1995, and all values are referenced
to that year. The unit of currency used is the ECU. The exchange rate was approximately
1 ECU to US$1.25 in 1995.
The central discount rate used for the study is 3%, with upper and lower rates of 0% and 10%
also used to show sensitivity to discount rate. The rationale for the selection of this range and
best estimate, and a broader description of issues relating to discounting, was given in an
earlier report (European Commission, 1995b).
2.4.7 Assessment of uncertainty
Uncertainty in externality estimates arises in several ways, including:
• The variability inherent in any set of data;
• Extrapolation of data from the laboratory to the field;
• Extrapolation of exposure-response data from one geographical location to another;
• Assumptions regarding threshold conditions;
• Lack of detailed information with respect to human behaviour and tastes;
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Methodology
• Political and ethical issues, such as the selection of discount rate;
• The need to assume some scenario of the future for any long term impacts;
• The fact that some types of damage cannot be quantified at all.
It is important to note that some of the most important uncertainties listed here are not
associated with technical or scientific issues, instead they relate to political and ethical issues,
and questions relating to the development of world society. It is also worth noting that, in
general, the largest uncertainties are those associated with impact assessment and valuation,
rather than quantification of emissions and other burdens.
Traditional statistical techniques would ideally be used to describe the uncertainties associated
with each of our estimates, to enable us to report a median estimate of damage with an
associated probability distribution. Unfortunately this is rarely possible without excluding
some significant aspect of error, or without making some bold assumption about the shape of
the probability distribution. Alternative methods are therefore required, such as sensitivity
analysis, expert judgement and decision analysis. In this phase of the study a more clearly
quantified description of uncertainty has been attempted than previously. Further discussion
is provided in Appendix VII, though it is worth mentioning that in this area of work
uncertainties tend to be so large that additive confidence intervals usually do not make sense;
instead one should specify multiplicative confidence intervals. The uncertainties of each stage
of an impact pathway need to be assessed and associated errors quantified. The individual
deviations for each stage are then combined to give an overall indication of confidence limits
for the impact under investigation.
2.5 Priority Impacts Assessed in the ExternE Project
2.5.1 Fossil technologies
The following list of priority impacts was derived for the fossil fuel chains considered in the
earlier phases of ExternE. It is necessary to repeat that this list is compiled for the specific
fuel chains considered by the present study, and should be reassessed for any new cases. The
first group of impacts are common to all fossil fuel chains:
1. Effects of atmospheric pollution on human health;
2. Accidents affecting workers and/or the public;
3. Effects of atmospheric pollution on materials;
4. Effects of atmospheric pollution on crops;
5. Effects of atmospheric pollution on forests;
6. Effects of atmospheric pollution on freshwater fisheries;
39
ExternE National Implementation. Spain
7. Effects of atmospheric pollution on unmanaged ecosystems;
8. Impacts of global warming;
9. Impacts of noise.
To these can be added a number of impacts that are fuel chain dependent:
10. Impacts of coal and lignite mining on ground and surface waters;
11. Impacts of coal mining on building and construction;
12. Resettlement necessary through lignite extraction;
13. Effects of accidental oil spills on marine life;
14. Effects of routine emissions from exploration, development and extraction from oil and
gas wells.
2.5.2 Nuclear technologies
The priority impacts of the nuclear fuel chain to the general public are radiological and nonradiological health impacts due to routine and accidental releases to the environment. The
source of these impacts are the releases of materials through atmospheric, liquid and solid
waste pathways.
Occupational health impacts, from both radiological and non-radiological causes, were the
next priority. These are mostly due to work accidents and radiation exposures. In most cases,
statistics were used for the facility or type of technology in question. When this was not
possible, estimations were taken from similar type of work or extrapolated from existing
information.
Impacts on the environment of increased levels of natural background radiation due to the
routine releases of radionuclides have not been considered as a priority impact pathway,
except partially in the analysis of major accidental releases.
2.5.3 Renewable technologies
The priority impacts for renewables vary considerably from case to case. Each case is
dependent upon the local conditions around the implementation of each fuel chain. For the
wind fuel chain (European Commission, 1995f) the following were considered:
1. Accidents affecting the public and/or workers;
2. Effects on visual amenity;
3. Effects of noise emissions on amenity;
40
Methodology
4. Effects of atmospheric emissions related to the manufacture of turbines and construction
and servicing of the site.
Whilst for the hydro fuel chain (European Commission, 1995f) another group was considered:
1. Occupational health effects;
2. Employment benefits and local economic effects;
3. Impacts of transmission lines on bird populations;
4. Damages to private goods (forestry, agriculture, water supply, ferry traffic);
5. Damages to environmental goods and cultural objects.
2.5.4 Related issues
It is necessary to ask whether the study fulfils its objective of consistency between fuel chains,
when some impacts common to a number of fuel chains have only been considered in a select
number of cases. In part this is due to the level of impact to be expected in each case - if the
impact is likely to be large it should be considered in the externality assessment. If it is likely
to be small it may be legitimate to ignore it, depending on the objectives of the analysis. In
general we have sought to quantify the largest impacts because these are the ones that are
likely to be of most relevance to questions to which external costs assessment is appropriate.
2.6 Summary
This Chapter has introduced the ‘impact pathway’ methodology of the ExternE Project. The
authors believe that it provides the most appropriate way of quantifying externalities because
it enables the use of the latest scientific and economic data.
Critical to the analysis is the definition of fuel chain boundaries, relating not only to the
different stages considered for each fuel chain, but also to the:
• Location of each stage;
• Technologies selected for each stage;
• Identified burdens;
• Identified impacts;
• Valuation criteria;
• Spatial and temporal limits of impacts.
41
ExternE National Implementation. Spain
In order to achieve consistency it is necessary to draw very wide boundaries around the
analysis. The difficulty with successfully achieving an assessment on these terms is slowly
being resolved through the development of software and databases that greatly simplify the
analysis.
The definition of ‘system boundary’ is thus broader than is typically used for LCA. This is
necessary because our analysis goes into more detail with respect to the quantification and
valuation of impacts. In doing so it is necessary to pay attention to the site of emission
sources and the technologies used. We are also considering a wider range of burdens than is
typical of LCA work, including, for example, occupational health effects and noise.
The analysis requires the use of numerous models and databases, allowing a logical path to be
followed through the impact pathways. The functions and other data originally used by
ExternE were described in an earlier report (European Commission, 1995b). In the present
phase of the study this information has been reassessed and many aspects of it have been
updated (see European Commission, 1998). It is to be anticipated that further methodological
changes will be needed in the future, as further information becomes available particularly
regarding the health effects of air pollution and global warming impacts, which together
provide some of the most serious impacts quantified under the study.
42
3. COAL FUEL CYCLE
3.1 Definition of the coal fuel cycle, technology and site
3.1.1 Technology description
This fuel cycle was assessed in the first stage of the participation of CIEMAT within the
ExternE Project (Linares et al, 1995). It has now been updated, according to the latest
information.
The reference technology for this fuel cycle is a hypothetical 1050 MW power plant, which
would be installed in Valdecaballeros, in Southwestern Spain. This hypothetical plant would
be based on 1990 technology, with FGD, ESP, and low NOx burners.
Coal would come from Puertollano coal mines, some 200 km away from the site.
The stages of this fuel cycle are shown in the following diagram.
Plant
construction
Coal extraction
Fuel transport
Power
generation
ELECTRICITY
Waste disposal
Limestone
extraction
Limestone
transport
Plant
dismantling
Figure 3.Error! Unknown switch argument. Stages of the coal fuel cycle
43
ExternE National Implementation. Spain
3.1.1.1 Coal extraction
Coal will be extracted from the open-cast mine located in Puertollano, some 200 km away
from Valdecaballeros. The area occupied by the mine is around 32,000 ha.
Nowadays, this mine produces 700 kt/yr of coal. For the case studied, some 4.2 Mt would be
required, so the production of the mine should be increased.
The basic mining operations are as follows. First the topsoil is ragged off, and the mine refuse
is spreaded at the back of the mining area. Then there is a drilling and controlled blasting
stage, and the coal is extracted with diggers, and transported by dumpers to the treatment area.
The treatment consists in crushing and screening, to obtain marketable coal. In order to avoid
the physical impact of the mining, soil restoration is permanently carried out.
A diagram of this stage is shown in the following diagram.
4.2 Mt coal/yr
1,680 workers
Occupational accidents
Mining equipment
COAL EXTRACTION
Air emissions
79 t/yr NOx
5.6 t/yr SO2
4400 t/yr PM10
47.6 t/yr CO
7.9 t/yr HC
26348 t/yr CO2
Figure 3.Error! Unknown switch argument. Coal extraction
The characteristics of the coal extracted are shown in the following table.
44
Coal Fuel Cycle
Table 3.Error! Unknown switch argument. Characteristics of Puertollano coal
PROXIMATE ANALYSIS (%w dry basis)
Fixed carbon
39.09
Volatiles
25.44
Ashes
35.47
ULTIMATE ANALYSIS (%w dry basis)
Carbon
52.22
Oxygen
6.49
Sulphur
1.29
Hydrogen
3.33
Nitrogen
1.12
Chlorine
0.07
Phosphorus
0.0096
Ash
35.47
HIGH HEATING VALUE: 4899 kcal/kg dry basis
3.1.1.2 Coal transport
Coal will be transported by train through the railway line Madrid-Badajoz. The distance to the
power plant is around 200 km. The trainload per trip will be 1,000 t, so 4,200 trips per year
will be required.
Air emissions corresponding to this transport have been scaled from Lauffen values (European
Commission, 1995c).
The inputs and outputs of this stage are shown in the following figure.
4,200 trips
840,000 km
4.2 Mt coal
COAL TRANSPORT
Railway
accidents
4.2 Mt coal
Air emissions
38136 t/yr CO 2
28 t/yr NO x
26 t/yr SO 2
1964 t/yr PM 10
Figure 3.Error! Unknown switch argument. Coal transport stage
45
ExternE National Implementation. Spain
3.1.1.3 Limestone production
The annual limestone demand to feed the FGD is 262,500 t. It will be extracted from a quarry
located some 50 km away from the power plant.
262,500 t limestone
Quarrying
equipment
105 workers
LIMESTONE PRODUCTION
Occupational
accidents
Air emissions
171 t/yr PM10
211 t/yr NOx
Figure 3.Error! Unknown switch argument. Limestone production
3.1.1.4 Limestone transport
Limestone will be transported in 25-t trucks, to the power plant.
46
Coal Fuel Cycle
5880 trips
294,000 km
262,500 t limestone
262,500 t limestone
LIMESTONE TRANSPORT
Road
accidents
Air emissions
1341 t/yr CO2
257 t/yr NOx
1 t/yr SO2
60 t/yr PM10
Figure 3.Error! Unknown switch argument. Limestone transport
3.1.1.5 Power generation
The technology selected is Pulverized Fuel combustion. The plant will consist of three groups
with an installed electric power of 350 MW each, and will have an overall production of 7,500
GWh/yr.
Each group is composed by a boiler, and a turboalternator, and they share the same stack,
coalyard, and disposal ash system. The cooling system is based on a reservoir built for that
purpose next to the plant.
The overall net efficiency is 33.1%.
In order to reduce the atmospheric emissions, the plant will be equipped with cyclones,
effective electrostatic precipitators (ESP), flue gas desulphurization (FGD), and low NOx
burners. The efficiencies of these devices are 99.8% for the cyclones and ESP, 90% for the
FGD, and 50% for the low NOx burners.
The construction period will last for three years, and the plant lifetime is estimated to be
150,000 full load hours.
An input-output diagram of this stage is shown on the following figure.
47
ExternE National Implementation. Spain
Occupational accidents
191,800 t steel
532,600 t concrete
6,800 t other materials
PLANT
CONSTRUCTION
7,500 GWh
4.2 Mt coal
262,500 t limestone
Air emissions
333 kg SO2
1 t NOx
421 kg PM10
326 t CO2
Occupational accidents
PLANT
OPERATION
1.32 Mt ashes
451,500 t gypsum
Air emissions
7612 kt CO2
2258 t PM10
8850 t SO2
12765 t NOx
2766 m3water/day
PLANT
DISMANTLING
Occupational accidents
Figure 3.Error! Unknown switch argument. Power generation stage
3.1.1.6 Waste disposal
The most significant waste products of this coal fuel cycle are ashes and gypsum. These solid
wastes will be transported by truck to a landfill and to cement industries, sited some 50 km
away from the power plant.
48
Coal Fuel Cycle
52,970 trips
2,648,500 km
1.32 Mt ash
WASTE DISPOSAL
451,500 t gypsum
Road
accidents
Air emissions
16,204 t/yr CO2
302 t/yr NOx
17 t/yr SO2
732 t/yr PM10
Figure 3.Error! Unknown switch argument. Waste disposal
3.1.2 Site description
3.1.2.1 Geographical location
The site proposed for the location of the coal power plant is Valdecaballeros, in the province
of Badajoz, in Southern Spain. The site has been chosen because of the existence of a nonfinished nuclear plant on it, of which some infrastructure might be used for our power plant.
The proposed site is 4 km away from the nearest village, Valdecaballeros, 180 km to the
Southwest of Madrid, in a sparsely populated area, with abundance of Mediterranean forests
and mostly devoted to agriculture. Error! Unknown switch argument. shows the location of
the power plant within Spain.
49
ExternE National Implementation. Spain
Madrid
Power plant
Badajoz
Figure 3.Error! Unknown switch argument. Situation of the power plant within Badajoz and
Spain.
The area is crossed from east to west by the Guadiana river, and is surrounded by several
mountain ranges, of which the most important in Sierra de Guadalupe range, to the northwest
of the site, with a maximum height of 1,443 m.
To the southwest lies the Serena valley, which is a flat area with an average altitude of 350 m.
The geographical data of the site are the following:
Municipality:
Valdecaballeros
Province:
Badajoz
Region:
Extremadura
Latitude:
39º 17’27 N
Longitude:
5º 10’40 W
Altitude:
383.42 m
UTM coordinates:
x = 312, 178.94
y = 4,351,531.81
Local impacts will be studied for an area 100x100 km around the power plant.
50
Coal Fuel Cycle
3.1.2.2 Topography
The area is bordered to the NW by the Sierra de Guadalupe and to the N and NNE by the
Sierra de Altamira. Villuercas and Cervales peaks, with an altitude of 1,200 m and 1,443 m
can be seen from the site at angles of 2º39’ and 2º02’ respectively, being 26,5 and 29,5 km
away.
To the ESE lies Sierra de la Rinconada, which reaches 1º04’ over the horizon at a distance of
16.5 km. A 669 m-high hill about 8 km away can be seen at an angle of 1º58’, and another to
the SW, at 7 km distance has an angle of 1º41 on the horizontal plane. This can be observed in
Error! Unknown switch argument..
To the SW, along the Guadiana river valley, lies the flat area known as Serena Valley with an
average altitude of 350 m.
Figure 3.Error! Unknown switch argument. Topography of the area
51
ExternE National Implementation. Spain
3.1.2.3 Hydrology
Surface waters
The power plant will be sited on the right-hand bank of the Guadalupejo river, a tributary of
river Guadiana. This Guadiana river is the main watercourse of the area, fed by several
tributaries, including: Zújar, Estena, Estenilla, Guadarranque, Guadalupejo, and Ruecas.
Besides from the small reservoir located beside the site, with a maximum normal capacity of
554 hm3, other large reservoirs exist inside the area, used both for irrigation and electricity
production purposes. These are Cijara (1,670 hm3), Orellana (824 hm3), Zújar (723 hm3), and
García de Sola (554 hm3).
These reservoirs are fed mainly by the river flow, with very little contribution from
underground waters or surface runoff.
Underground waters
Two basic types of aquifer can be found in the region: one located in the Ordovician
quartzites, with permeability though fissuring and with a well defined environment, and
another one made up of detritus material of the Miocene and Quaternary with permeability
through porosity.
Ordovician quartzites
This aquifer can be found in a quartzite synclinal to the SW of the area. It is a very closed
structure, with intense tectonics that facilitate infiltration. It covers an area of some 13 km2,
and is flanked by piedmontite deposits. Below, slate and whinstone can be found, which form
an impermeable horizon. One of its springs supplies Valdecaballeros.
Water reserves are estimated to be not greater than 5 hm3. Water quality is excellent, with a
very small number of dissolved solids, always lower than 100 mg/l. They are very slightly
bicarbonated, neutral or slightly acidic.
Detritus aquifers
They include two types:
Miocene and fanglomeratic sediments: The geometry of these aquifers is irregular. They are
fed directly and have no more than 15% of useful rainfall. This is favoured by the eminent
flatness of the infiltration surface. In winter there may be flooded areas as a result of
saturation, because of low transmisiveness.
There are few instalations exploiting these aquifers. They are generally broad diameter wells,
3-6 m deep. Water quality is good, with low dissolved solid content (100 mg/l).
Quaternary sediments: Two aquiferal strata in very close contact can be distinguished: flood
and alluvial plains.
52
Coal Fuel Cycle
Flood plains aquifers are located between the quartzite alignment of Valdecaballeros and
Sildavillo river, and near to Castiblanco. They extend over 50 km2. They are made up of
gravels, sands and clays in variable proportions.
They are fed directly by rainfall. Natural drainage takes place towards the alluvials which it
feeds. Water level in summer is around 2 m, and in winter there may be even flooded areas.
Water quality is good, with a dissolved solids content between 100 and 200 mg/l. It is slightly
bicarbonated and chlorinated. There are only traces of nitrates.
Alluvial aquifers surround Guadalupejo and Sildavillo rivers, and a certain number of streams.
They are fed mainly by surface runoff, and by the adjacent flood plains and rainfall.
Transmissiveness is good, allowing 2.5 l/s flows. Water quality is very good, with dissolved
solid contents less than 100 mg/l, and chlorides and carbonates present in very small
quantities.
Two of the aquifers, the alluvial quaternary, and the ordovician quartzite ones, are locally
exploited, what has to be taken into account for potential pollution problems. Generally, they
are used for irrigation and livestock, and in some cases as drinking water.
Alluvial quaternary aquifers have a high risk of chemical and biological contamination, as
they are free aquifers with a water table near the surface. This surface has generally well
developed soils, which are suitable for agricultural exploitation, and are therefore likely to
contain fertilizers and pesticides residues.
3.1.2.4 Climatology
In general terms, the climate of the area may be considered as continental, mitigated in winter
and spring by the Atlantic influence, coming with westerly winds. Winters are not excessively
cold, and very wet. Summer temperatures can be very high.
The most intense precipitations are produced by depressions near the Portuguese coasts, or SE
England, and are accompanied by westerly winds. The amound of precipitation varies greatly,
increasing with altitude. The Sierra de Guadalupe range and its foothills cause the
precipitation to settle, affecting to a certain extent the Valdecaballeros area, where
precipitation is greater than the average of the region.
Winds tend not to be strong, and the danger of hurricanes is negligible.
Meteorological data has been obtained from the weather station located in the power plant
site. However, as relatively little time has been recorded, these data have only been used as
complementary. Basic data have been obtained from the weather station of Guadalupe, 24 km
away from the site (lat 39º27 ‘N, long 5º19’W, alt 640 m). Data for 40 years have been used to
calculate the annual and monthly averages.
53
ExternE National Implementation. Spain
Error! Unknown switch argument. presents the Guadalupe’s area main weather
characteristics.
Table 3.Error! Unknown switch argument. Meteorological data for Guadalupe
Solar radiation
(cal/cm2day)
Average daily
insolation(hours)
Wind speed (m/s)
Abs. max T (ºC)
Avg max. T (ºC)
Avg T (ºC)
Avg min T (ºC)
Abs min T (ºC)
Avg. Precip. (mm)
Max precip. in 24h
(mm)
Relative Hum. (%)
ETP Thornthwaite
(mm)
ETP Penman (mm)
E
166.4
F
220.4
M
334.9
A
434.6
M
536.1
J
598.7
J
618.5
A
551.7
S
431.6
O
284.0
N
186.9
D
147.4
Annual
4.1
4.3
6.0
7.3
9.1
10.6
11.4
10.6
8.8
6.1
4.6
3.9
7.2
1.84
21
10.0
7.0
3.9
-4.0
119.9
97.0
2.11
23
11.3
7.9
4.5
-7
107.0
86
2.01
27
14.4
10.4
6.4
-6
80.8
60
2.49
30
16.4
12.3
8.1
-2
75.8
83
2.90
35
21.2
16.5
11.7
2
3.0
44.4
2.64
42
26.3
21.0
15.7
2
31.2
42
2.82
42
31.6
25.6
19.7
9.5
7.2
34.5
2.29
41
30.3
24.7
19.1
0
10.3
40.5
2.10
44
27.0
22.0
17.0
7
33.8
62.6
2.05
32
19.8
16.0
12.2
3
80.5
62
1.44
27
14.1
10.8
7.4
-2
124.8
80
2.11
23
10.7
7.7
4.6
-5
136.5
96
2.23
44
19.4
15.2
10.9
-7
860.8
97
87
13.8
84
16.5
79
31.3
73
43.8
64
77.4
55
114.3
46
158.3
47
140.4
56
103.2
68
56.7
80
27.0
87
15.4
68.8
798.1
10.9
22.6
58.5
82.6
127.6
140.4
147.9
109.5
76.4
41.2
14.2
6.4
838.4
3.1.2.5 Land use
General distribution
As has been mentioned before, the major part of the area is rural, with a large amount of
agricultural land and pastures. Forests are also quite important, specially Mediterranean open
forest or dehesa. Data on land use has been obtained from the Ministry of Agriculture, on a
municipal basis. Error! Unknown switch argument. shows the overall distribution for the
area.
Other
11%
Forests
39%
Agriculture
32%
Pastures
18%
Figure 3.Error! Unknown switch argument. General land distribution
54
Coal Fuel Cycle
Agriculture
The most important crops are olives, grapes, oats, barley and wheat. The following figures
show the relative surface and value of this crops.
Surface
Wheat
9%
Others
19%
Barley
13%
Olives
35%
Oats
21%
Grapes
3%
Figure 3.Error! Unknown switch argument. Surface distribution of the main crops
Value
Wheat
5%
Barley
7%
Others
27%
Oats
7%
Grapes
8%
Olives
46%
Figure 3.Error! Unknown switch argument. Value distribution of the main crops
Ecosystems
Cijara National Hunting Reserve
It comprises the area beside Cijara reservoir, within the municipalities of Helechosa de los
Montes, Villarta de los Montes, Fuenlabrada de los Montes, and Herrera del Duque, covering
68,787 ha.
It is mostly covered by timber forests, mainly Pinus pinea and Pinus pinaster. Natural
vegetation includes evergreen oak, cork oak, Cistus sp, Arbutus unedo, and other shrubs.
There is an abundant wildlife, such as deer, wild boar, game, and other species.
Some 25,000 m3 of timber are collected each year. In addition, 25,000 cows, 40,000 sheep,
and 8,000 goats graze in the area. Agricultural crops are not significant. The largest revenue
comes from hunting and fishing licenses.
55
ExternE National Implementation. Spain
Orellana and Sierra de Pela
This area covers the Orellana reservoir, including the Sierra de Pela range. It is part of the
municipalities of Talarrubias, Puebla de Alcocer, and Casas de Don Pedro. Its extension is
24,842 ha.
The dominant landscape is the dehesa, along with croplands and olive groves.
This area has been declared Special Bird Protection Zone, because of its important bird
population.
Puerto Peña
The area, mainly that surrounding García de Sola reservoir, covers part of the municipalities
of Herrera del Duque, Valdecaballeros, Castilblanco, Talarrubias, Fuenlabrada de los Montes,
Garbayuela, and Puebla de Alcocer, over more than 22,000 ha.
Natural vegetation includes evergreen and cork oak, and different shrubs. Hunting species are
abundant in the area.
Its main revenues come from timber (1,300 m3/yr of pine), crops (4,000 ha), livestock (3,500
cows, 45,000 sheep, 7,600 goats), hunting and fishing.
Sierra de las Villuercas
Its extension is 23,025 ha, covering part of the municipalities of Guadalupe, Alía, Cañamero,
Villar del Pedroso, Cabañas del Castillo, Robledollano, Navalvillar de Ibor, Castañar de Ibor,
and Navezuelas.
It features the highest peak of the area, as well as several rivers. Vegetation is very diversified,
with trees, shrubs, and land crops. There is a very rich wildlife, specially birds.
The most important source of revenue for the area is agriculture and livestock.
3.1.2.6 Population
The total population of the local area is 110,330, according to Eurostat. This results in a
population density of 11 inh/km2, what is very low, much lower than the population density of
the province of Badajoz (31.75 inh/km2) or that of Spain (78 inh/km2).
The population distribution according to age is shown in the following table.
Table 3.Error! Unknown switch argument. Population distribution according to age
Children (under 5 years)
6.6%
Children (under 15 years)
22.01%
Adults
77.99%
56
Coal Fuel Cycle
3.2 Overview of burdens
The major burdens identified for this fuel cycle are the atmospheric emissions of pollutants
from the mining and power generation stage, liquid effluents and solid wastes from mining
and power generation, and occupational accidents from the mining stage.
3.2.1 Atmospheric emissions
Pollutant emissions are produced all along the fuel cycle, due both to the contribution of fossil
fuels, and also to the fugitive dust removed in some operations.
Table 3.Error! Unknown switch argument. Atmospheric emissions of the coal fuel cycle (in
g/MWh)
1. Coal mining
2. Coal transport
4. Limestone extraction
5. Limestone transport
6. Power generation
8. Waste transport
TOTAL
nd : not determined
PM10
588
262
22.8
8.0
301
98
1279
SO2
0.8
3.5
nd
0.1
1180
2.3
1187
NOx
10.5
3.7
28.1
34
1702
40
1819
CO2
3513
5085
nd
179
1,015,000
2160
1,025,937
CO
6.3
nd
nd
nd
nd
nd
6.3
HC
1.1
nd
nd
nd
nd
nd
1.1
As may be seen, most of the pollutants come from the power generation stage, except for the
particulate emissions, which are also very high for the coal extraction and transport stages, in
which large amounts of fugitive dust are released.
3.2.2 Liquid effluents
Liquid effluents arise from the mining stage, because of the drainage required for the water
bags existing in the mine. These waters have a higher sulphate, iron and manganese contents
than allowed, and so they have to be treated. This treatment includes precipitation, separation,
and pH adjustment. The exiting water has a pH between 5.5 and 9.5, 2 mg/l of condensed
materials, 10 mg/l iron, 10 mg/l manganese, and 2,000 mg/l sulphates. The total amount of
water released is 4,400 m3 per year.
There are also water effluents from the power generation stage, associated to the cooling
system, FGD plant, coalyard, solid waste disposal, and the boiler. The most important are
those coming from the FGD and from the cooling system, amounting respectively to 800,000
m3 and 21,000 m3 per year.
3.2.3 Solid wastes
As for the rest of the fuel cycle, solid wastes are produced mainly in the power generation and
mining stages
57
ExternE National Implementation. Spain
The solid wastes generated in the mining phase are the gypsum produced in the waste
treatment, of which 1,120,000 t are produced yearly, and the non-combustible fraction of the
coal, which is spreaded at the back of the mine.
Regarding the power generation, the solid wastes produced are ashes and slags, and gypsum
from the FGD.
20% of the ash is furnace bottom ash, while the rest is fly ash captured in the ESP. The annual
volume produced is 1.32 Mt.
The gypsum produced as a final product of the FGD amounts to 451,500 t per year.
3.2.4 Occupational accidents
As said before, most of the occupational accidents are produced in the mining stage. However,
it has to be said that the accident rate used here comes from the whole Spanish mining sector,
in which most mines are underground. Open-cast mines, such as the one studied here, should
have lower accident rates.
Table 3.Error! Unknown switch argument. Occupational accidents per TWh
1. Coal mining
4. Limestone extraction
6. Power generation
10-11. Construction and
dismantling
nd : not determined
Fatal accidents
1.5e-1
5.0e-3
1.7e-2
9.3e-3
Major injuries
14
1.6e-1
4.5e-1
0.27
Minor injuries
63.8
7.4e-1
17
9.5
3.3 Selection of priority impacts
The impacts considered in this fuel cycle are shown in the next table.
Table 3.Error! Unknown switch argument. Impacts of the biomass/lignite fuel cycle.
Impacts
Mining
Transport Generation Waste disposal Construction
Global warming
x
x
x
x
x
Public health
x
x
x
x
Occupational health
x
x
x
x
Crops
x
x
x
Forests
x
x
x
Ecosystems
x
x
x
x
Materials
x
x
x
Noise
x
x
x
x
Road traffic
x
x
Visual impact
x
x
x
x
58
Coal Fuel Cycle
The impacts considered most relevant are those caused by atmospheric emissions from the
power generation stage on human health, materials, crops and ecosystems, and global
warming.
Although PM10 emissions from the mining stage are really large it is expected that their
impact will not be too high, since they are emitted near the ground level, and so they are
quickly deposited. Thus, they probably affect only mine workers, and this effect is already
included in the occupational accidents and diseases.
Liquid effluents both from the mining and power generation are expected to have significant
effects. However, their quantification is not yet possible.
Accounting for all this, the priority impacts to be assessed are:
• Public health,
• Occupational health,
• Crops,
• Ecosystems,
• Materials,
• Global warming.
3.4 Quantification of impacts and damages
3.4.1 Coal extraction
Coal extraction has several environmental consequences, specially impacts on miners health,
and also water pollution.
Nevertheless, most of these impacts are difficult to quantify. Impacts on miners health may be
estimated using dose-response functions. However, these functions have been estimated for
underground mines, and so they are difficult to extrapolate to open-cast mines, in which these
impacts are expected to be much lower. Therefore, only occupational accidents have been
taken into account. These accidents have been estimated using the accident rate provided by
the Ministry of Labour. As most Spanish mines are underground, data on accidents will not be
adapted to surface mining, thus resulting in a probable overestimation of the results.
As for water pollution impacts, there is not yet a clear methodology for assessing them, and so
this has not been attempted.
59
ExternE National Implementation. Spain
As mentioned before, PM10 impacts from the mining will not be considered, nor local impacts
such as noise or visual impact.
Table 3.Error! Unknown switch argument. Impacts and damages of coal extraction
Impact
Occupational accidents
Deaths
Major injuries
Minor injuries
Global warming
na: not applicable
Burden
Impacts
Unit
per TWh
1.5e-1
14.0
63.8
CO2
mECU/kWh
4.7e-1
1.7
1.2e-1
1.3e-2 - 4.9e-1
Damages
ECU/t poll.
σg
na
na
na
3.8 - 139
A
A
A
C
3.4.2 Coal transport
The impacts of coal transport have been assessed using German data, which assign a
proportional share of all railroad deaths to coal transport, based on the total weight of material
transported (European Commission, 1995c)
Table 3.Error! Unknown switch argument. Impacts and damages of fuel transport
Impact
Occupational accidents
Deaths
Major injuries
Minor injuries
Public accidents
Deaths
Major injuries
Minor injuries
Global warming
na: not applicable
Burden
Impacts
Unit
per TWh
mECU/kWh
Damages
ECU/t poll.
σg
1.5e-2
1.2e-1
10.1
4.7e-2
1.5e-2
1.9e-2
na
na
na
A
A
A
2.9e-2
1.7e-2
7.9-e2
9.0e-2
2.1e-3
1.5e-4
1.9e-2 - 7.1e-1
na
na
na
3.8 - 139
A
A
A
C
CO2
3.4.3 Limestone production
Accident rates for non-energetic mineral extraction have been used, in the absence of data for
quarry workers. The productivity used has been that of surface mining.
Table 3.Error! Unknown switch argument. Impacts and damages of limestone production
Impact
Occupational accidents
Deaths
Major injuries
Minor injuries
na: not applicable
60
Burden
Impacts
Damages
Unit
per TWh mECU/kWh
ECU/t poll.
5.0e-3
1.6e-1
7.4e-1
1.6e-2
2.0e-2
1.4e-3
na
na
na
σg
A
A
A
Coal Fuel Cycle
3.4.4 Limestone transport
The major impact of this stage is that produced by road accidents, which have been estimated
based on Spanish truck accident rates.
Table 3.Error! Unknown switch argument. Impacts and damages of limestone transport
Impact
Road accidents
Deaths
Major injuries
Minor injuries
Global warming
na: not applicable
Burden
Impacts
Unit
per TWh
1.8e-3
4.9e-3
2.2e-2
CO2
mECU/kWh
5.6e-3
6.1e-4
4.2e-5
1.0e-3 - 2.5e-2
Damages
ECU/t poll.
na
na
na
3.8 - 139
σg
A
A
A
C
3.4.5 Power generation
The major part of the damages of this stage correspond to health effects caused by the
atmospheric emissions of the power plant, and to the global warming effects of CO2
emissions.
As mentioned before, no impacts of liquid effluents have been assessed, although they might
be significant.
The damage on crops is quite small compared to the others. However, it has to be noted that
only the impact on cereals, potatoes, and sugar beet has been assessed, while the most
important and valuable crops of the area are others. This fact should produce an
underestimation of the damages.
As for occupational accidents, results include those of the power plant construction and
dismantling.
61
ExternE National Implementation. Spain
Table 3.Error! Unknown switch argument. Impacts and damages of power generation
Impact
Human health
Chronic YOLL
Acute YOLL
Morbidity
Crops
Ecosystems
Materials
Occupational accidents
Deaths
Major injuries
Minor injuries
Global warming
na: not applicable
Burden
TSP
Nitrates
Sulfates
SO2
Ozone
Nitrates
Ozone
SO2
Sulfates
TSP
SO2
Ozone
N dep.
Impacts
Unit
per TWh
years
years
years
years
2.37e+1
1.43e+2
7.53e+1
9.82e-1
cases
8.91e+3
cases
cases
cases
dt yield loss
3.75e-1
4.69e+3
1.48e+3
9.09e+5
kg fertilizer
added
Ac. dep.
kg lime
added
N dep.
km2 exceed.
area
SO2
km2 exceed.
area
NOx
km2 exceed.
area
SO2
m2 maint.
area
mECU/kWh
Damages
ECU/t poll.
σg
-1.25e+5
2.00
12.1
6.35
1.52e-1
7.01e-1
1.55
1.25
2.95e-3
7.95e-1
2.58e-1
3.39e-2
5.96e-1
-2.2e-3
6661
7098
5418
130
412
909
732
3
678
859
29
350
na
B
B?
B
B
B
A-B?
B
A-B
A-B
A-B
A
B
A
1.04e+6
1.78e-2
na
A
0
na
0
0
na
0
0
na
0
7.45e+3
1.20e-1
102
B
1.7e-2
4.5e-1
17
5.3e-2
5.6e-2
3.2e-2
3.9 - 141
na
na
na
3.8 - 139
A
A
A
C
CO2
3.4.6 Waste disposal
The major impact from this stage is the increment in road accidents caused by the road
transport of the solid wastes.
Table 3.Error! Unknown switch argument. Impacts and damages of waste disposal
Impact
Road accidents
Deaths
Major injuries
Minor injuries
Global warming
na: not applicable
62
Burden
Impacts
Damages
Unit
per TWh mECU/kWh
ECU/t poll.
1.9e-1
5.9e-2
2.7e-1
CO2
5.9e-1
7.3e-3
5.2e-4
8e-3 – 3e-1
na
na
na
3.8 - 139
σg
A
A
A
C
Coal Fuel Cycle
3.5 Summary and interpretation of results
The summary of the externalities assessed for the coal fuel cycle is shown in the following
table.
Table 3.Error! Unknown switch argument. Damages of the coal fuel cycle
mECU/kWh
σg
POWER GENERATION
Public health
Mortality*- YOLL (VSL)
21.4 (79.8)
B
of which TSP
2.0 (7.4)
SO2
6.6 (27.4)
NOx
12.1 (44.3)
NOx (via ozone)
0.70
Morbidity
of which TSP, SO2, NOx
2.6
A
NOx (via ozone)
1.3
B
Accidents
nq
A
Occupational health
0.14
A
Major accidents
nq
Crops
0.62
B
of which SO2
1.8e-2
NOx (via ozone)
0.60
Ecosystems
ng
B
Materials
0.12
B
Noise
nq
Visual impacts
nq
Global warming
C
low
3.9
mid 3%
18.3
mid 1%
46.7
upper
141.1
OTHER FUEL CYCLE STAGES
Public health
0.70
A
Occupational health
2.41
A
Ecological effects
nq
B
Road damages
nq
A
Global warming
C
low
0.04
mid 3%
0.20
mid 1%
0.50
upper
1.5
*Yoll= mortality impacts based on ‘years of life lost’ approach, VSL= impacts evaluated based on ‘value of
statistical life’ approach.
ng: negligible; nq: not quantified; iq: only impact quantified; - : not relevant
63
ExternE National Implementation. Spain
Table 3.Error! Unknown switch argument. Sub-total damages of the coal fuel cycle
YOLL (VSL)
low
mid 3%
mid 1%
upper
mECU/kWh
33.2 (91.6)
47.8 (106.2)
76.5 (134.9)
171.9 (230.3)
Table 3.Error! Unknown switch argument. Damages by pollutant
SO2 *- YOLL (VSL)
NOx *- YOLL (VSL)
PM10 *- YOLL (VSL)
NOx (via ozone)
CO2
ECU / t of pollutant
6384 (24008)
8020 (26939)
7507 (25775)
1500
3.8 - 139
*Yoll= mortality impacts based on ‘years of life lost’ approach, VSL= impacts evaluated based on ‘value of
statistical life’ approach.
The damages of the coal fuel cycle are quite high, even though the technology considered
includes most types of environmental protection systems, and the site chosen is not highly
populated. Even though CO2 damages dominate the results at their higher estimate, damages
excluding global warming are still high, about 30 mECU/kWh, which is the same magnitude
as private costs. If global warming damages are included, then damages reach really high
values, more than thrice of the private costs.
Therefore, it may be seen that even environmentally-advanced, standard technologies for coal
combustion are not clean enough if they are to compete with gas or renewable energies.
Changes to fluidized-bed combustion or gasification cycles are required to lower the damages
to reasonable terms, both by improving conversion efficiency (and thus reducing CO2
emissions) and by reducing pollutant emission rates.
Of the impacts, it has to be noted that the largest correspond to global warming, and to human
health effects of nitrates, both of which are indeed uncertain. More research on these topics
would produce better estimates of the total damages of this fuel cycle.
As for the impacts of the upstream stages of the fuel cycle, the most significant one is
occupational accidents, although this figure may possibly be overestimated, as this impact
might be internalized to a certain extent.
In spite of these possible overestimations, it has to be reminded that some impacts which
might prove to be significant have not been assessed, such as the impact of liquid effluents
from the mine, or the impacts of waste disposal.
64
4. NATURAL GAS FUEL CYCLE
4.1 Definition of the natural gas fuel cycle, technology and site
4.1.1 Technology description
The technology analyzed for this fuel cycle will be CCGT (combined cycle, gas turbine). The
fuel used will be Algerian natural gas, and the power plant will have an installed power of 624
MW, working an average of 7,500 hours per year.
The stages of the technology are shown in the following diagram.
Construction
Construction
Construction
Operation
Operation
Operation
Dismantling
PRODUCTION
ELECTRICITY
Dismantling
TRANSPORT
POWER GENERATION
Figure 4.Error! Unknown switch argument. Stages of the fuel cycle
These stages will be described in the following sections.
4.1.1.1 Production
The gas will be extracted from the Algerian gas field of Hassi R’Mel. This gas field was
discovered in 1956 and is one of the world’s largest gas fields, with proven reserves estimated
65
ExternE National Implementation. Spain
at 2.5. 1012 m3. The daily production is 3.7 107 m3. The average composition of the gas
produced in this field is shown in Error! Unknown switch argument..
Table 4.Error! Unknown switch argument. Average composition of Hassi R’Mel natural gas.
Components
Symbol Normal composition (%v)
Methane
CH4
91.2
Ethane
C2H6
7.4
Propane
C3H8
0.8
Butane
C4H10
0.1
Nitrogen
N2
0.5
Carbon dioxide
CO2
Hydrogen sulphide
H2S
Others
Source: SEDIGAS (1991)
No data is available for this stage regarding greenhouse gas emissions, materials or labour use.
However, since the gas used by the power plant studied will represent less than 1% of the gas
produced in the gas field, the impacts attributable to the power plant are expected to be
negligible.
4.1.1.2 Transport
Natural gas from the Hassi R'Mel gas field will be transported to the power plant by the
Maghreb-Europe pipeline. The outline of this pipeline is shown in the following figure.
Valdecaballeros
Magreb-Europe Project
Gas pipeline in operation
Gas pipeline in project
Gas pipeline in study
Compression station
Gas field
Hassi R´Mel
Figure 4.Error! Unknown switch argument. The Maghreb-Europe pipeline
66
Natural Gas Fuel Cycle
The pipeline has a total length of 1,595 km, from the gas field to the power plant. It is
designed for carrying over 1,100,000 Nm3/h of natural gas for the first years, with the
possibility of doubling its capacity later.
The pipeline is buried, and avoids large population centres and ecologically sensitive areas, or
those areas with archaeological importance. The environmental protection measures adopted
have been the same both for the European and African sections. The environmental impact of
the pipeline construction is expected to be very small, since the land affected is quite reduced
(a 30 m wide corridor), and it is restored in a few months.
For the crossing of the Strait of Gibraltar, no significant marine environmental impacts have
been identified by the environmental impact assessments carried out.
Valves are installed every 20 km along the pipeline, with associated equipment on the ground.
Two compressor stations have been built in the section from the gas field to the power plant.
However, only one of them is needed for the current gas volume transported. These
compressor stations have an installed power of 25 MW, with an average consumption of
3,500 m3/h of the natural gas.
The personnel needed for operation and maintenance of the pipeline is around 260 people,
most of them for the African section.
Due to the buried installation of the pipeline, its dismantling will not be considered.
A diagram with the inputs and outputs of this stage is shown in the following figure.
600,000 t steel
8,000 workers
(for 16 months)
1,596 km pipeline
PIPELINE
CONSTRUCTION
Occupational accidents
33.6 t SO2
1275.6 t CO2
3 t NOx
Occupational
accidents
1,100,000 m3/h
260 workers
PIPELINE OPERATION
26,124 t CO2
12,554 t CH4
40 kg NOx
Pipeline
accident risk
Figure 4.Error! Unknown switch argument. Transportation stage
67
ExternE National Implementation. Spain
Of the burdens identified, we will only assign to the fuel cycle studied the share corresponding
to the power plant consumption of the total gas volume transported.
4.1.1.3 Power generation
The natural gas energy will be transformed into electricity by means of a combined cycle,
without additional combustion, and with an efficiency of 52%.
The plant that will be considered is a hypothetical, gas fired combined cycle power plant, of
624 MW. The gas turbine chosen is representative of modern large industrial gas turbines
which are applicable for combined cycle power plants. The steam cycle design and the choice
of parameters are based on various sources, resulting in a typical steam cycle.
A configuration with one gas turbine and one steam turbine has been selected. Two modular
configuration with 312 MW have been used to obtain 624 MW in the combined cycle power
plant .
The gas turbine is the basic component of the power plant. The design of the rest of the
equipments will be based on the gas turbine dimensions.
The heat recovery boilers and the steam turbine would be provided by the same supplier of the
gas turbine in order to ensure a better coupling of the two thermodynamic cycles.
The steam cycle will operate with a double pressure without reheat system. The dual pressure
systems are more or less standardized design. The triple pressure systems will probably not
replace the dual pressure systems as the most common design approach, because of the
increased plant complexity and significantly higher investment cost.
The net plant efficiency (LHV basis, ISO conditions) will be around 52% and its availability
would be expected to be around 95%. The technical lifetime of the plant will be around 30
years. Its operation requires some 100 workers.
The plant construction period will be around 2 years. The materials required for construction
have been escalated from similar plants.
As for the environmental burdens of the operation, they include air emissions such as CO2,
NOx, and SO2 (the latter due to the use of oil as backup fuel for a 5% of the total
consumption), liquid emissions such as water purges or mineral oils, or solid emissions such
as filter sands or sludges. The plant is equipped with low NOx burners.
All the process, and its energy and material requirements, is shown in the following figure.
68
Natural Gas Fuel Cycle
600 workers (for 2 yrs)
20,000 m3 concrete
6,000 t steel
20,000 m3 cladding and roofing
POWER PLANT
CONSTRUCTION
810 t CO2
21 t SO2
2 t NOx
Occupational accidents
4,640 GWh electricity
853,200 .103 Nm3 gas/year
100 workers
POWER PLANT
OPERATION
POWER PLANT
DISMANTLING
1,860,640 t CO2
795 t SO2
1200 t NOx
Occupational accidents
80 t filter sands
48 t boiler acid wastes
2,000 t decarbonation sludges
250 t water make up sludges
34 t mineral oils
20,000 m3 concrete
6,000 t steel
20,000 m3 cladding and roofing
Figure 4.Error! Unknown switch argument. Power generation stage
4.1.2 Site description
Since the site chosen for the gas power plant is the same as for the coal fuel cycle assessed
previously, refer to section 3.1.2 for the description of the site.
4.2 Overview of burdens
The gas fuel cycle is rather clean compared to other fossil fuel cycles. Due to the nature of the
fuel, the only major burdens are the atmospheric emissions caused by the power generation,
and, to a lesser extent, solid wastes from power generation, and the risk of accidents along the
pipeline. However, this latter is almost negligible.
4.2.1 Atmospheric emissions
Atmospheric emissions are produced in all stages of the fuel cycle. Gas flaring and venting
occur during the gas extraction and transport. Also during the transport stage, atmospheric
emissions are produced in the compression stations, due to the gas consumption.
69
ExternE National Implementation. Spain
Table 4.Error! Unknown switch argument. Atmospheric emissions of the gas fuel cycle
(g/MWh)
1. Gas extraction
2. Gas transport
3. Power generation
TOTAL
nd : not determined
PM10
nd
nd
nd
nd
SO2
nd
nd
171
171
NOx
nd
8.6e-4
259
259
CO2
nd
563
401,000
401,563
CH4
nd
271
nd
271
4.2.2 Solid wastes
The solid wastes produced during the power generation stage include filter sands, boiler acid
wastes, water make-up sludges, and decarbonation sludges. The latter is the major one, with
some 2,000 t generated per year.
4.3 Selection of priority impacts
Due to the relatively low emissions of the natural gas fuel cycle, almost all the impacts will be
concentrated on global warming, public health effects, and on the effects of SO2 and NOx on
crops, ecosystems, forests and materials. Error! Unknown switch argument. displays the
impacts in each stage of the natural gas fuel cycle.
Table 4.Error! Unknown switch argument. Impacts of the natural gas fuel cycle.
Impacts
Extraction Transport Generation Construction
Global warming
x
x
x
x
Public health
x
x
Occupational health
x
x
x
Crops
x
x
Forests
x
x
Ecosystems
x
x
Materials
x
x
Noise
x
x
Visual impact
x
x
x
Accident risk
x
x
Noise and visual impacts are expected to be negligible.
So, the priority impacts that will be assessed are:
• Public health,
• Occupational health,
• Crops,
70
Natural Gas Fuel Cycle
• Forests,
• Ecosystems,
• Materials, and
• Global warming.
4.4 Quantification of impacts and damages
4.4.1 Extraction
The major impact identified within this stage is the global warming produced by CO2 and CH4
emissions. However, no data is available for Algerian gas wells regarding these emissions.
Anyway, their contribution to the total GHG emissions of the natural gas fuel cycle is
expected to be negligible, so no impacts have been quantified for this stage.
4.4.2 Transport
Again, the major impact for this stage is global warming, due to the CO2 emitted by the
compressor stations in the pipeline, and also to the CH4 vented from the pipeline.
Both occupational accidents from the pipeline construction and operation, and pipeline
accident risks are very small.
The effects on public health, or the environment, of the pollutant emissions released during
the pipeline construction and operation, have not been estimated, as they are distributed along
a very large area, and so the modelization of their dispersion is very complex. Nevertheless,
these effects may be assumed to be negligible, since the pollutant emissions of this stage
account for less than 1% of the total emissions of the fuel cycle.
Table 4.Error! Unknown switch argument. Impacts and damages of the transport stage
Impact
Occupational accidentsEU
Deaths
Injuries
Occupational accidentsNon-EU
Deaths
Injuries
Accident risk- EU
Deaths
Injuries
Accident risk- Non-EU
Deaths
Injuries
Burden
Impacts
Unit
per TWh
mECU/kWh
Damages
ECU/t poll.
σg
2.9e-4
1.3e-1
7.5e-4
2.5e-3
na
na
A
A
1.1e-3
5.9e-1
3.0e-3
1.1e-2
na
na
A
A
3.4e-5
1.3e-4
8.7e-5
2.4e-6
na
na
A
A
3.5e-2
1.2e-4
8.4e-5
2.3e-6
na
na
A
A
71
ExternE National Implementation. Spain
Impact
Global warming
Burden
Impacts
Unit
per TWh
CO2
CH4
mECU/kWh
2e-3 – 7.8e-2
2.2e-2 – 8.2 e-1
Damages
ECU/t poll.
3.8 - 139
81 - 2975
σg
C
C
na: not applicable
4.4.3 Power generation
The largest percentage of damage, besides from global warming, comes from chronic
mortality, specially from nitrates. Damages per t of NOx are also the highest.
Compared to public health effects, effects on crops and forests are negligible, being 3 to 4
orders of magnitude lower. However, it has to be noted that only cereals have been
considered, not high-value crops like fruits or legumes, which are important specially in
Mediterranean regions. Damages on materials, by contrast, are rather high, being only an order
of magnitude lower than for public health effects.
Local impacts have been calculated for crops, accounting for some 10% of the total impact.
No local assessment has been carried out for human health effects for SO2. However, it is
expected that the local contribution would be in the same range. It has to be noticed that this
local assessment has been done using the MESOILT2 atmospheric dispersion model, instead
of the ISC model included in EcoSense.
Table 4.Error! Unknown switch argument. Impacts and damages of power generation
Impact
Human health
Chronic YOLL
Acute YOLL
Morbidity
Crops
Ecosystems
Materials
Occupational accidents
Deaths
72
Burden
Nitrates
Sulfates
SO2
Ozone
Nitrates
Ozone
SO2
Sulfates
SO2
Ozone
N dep.
Impacts
Unit
per TWh
years
years
years
2.16e+1
1.10e+1
1.45e-1
cases
1.33e+3
cases
cases
dt yield loss
5.53e-2
6.75e+2
3.89e+2
kg fertilizer
added
Ac. dep.
kg lime
added
N dep.
km2 exceed.
area
SO2
km2 exceed.
area
NOx
km2 exceed.
area
m2 maint.
SO2
area
mECU/kWh
Damages
ECU/t poll.
σg
-1.92e+4
1.82
9.24e-1
2.24e-2
1.07e-1
2.34e-1
1.89e-1
4.35e-4
1.15e-1
2.84e-3
9.05e-2
-3.30e-4
7110
5430
132
412
914
732
2.56
676
16.7
350
na
B?
B
B
B
A-B?
B
A-B
A-B
A
B
A
1.53e+5
2.61e-3
na
A
0
na
0
0
na
0
0
na
0
1.11e+3
1.76e-2
103
B
8.4e-3
2.2e-2
na
A
Natural Gas Fuel Cycle
Impact
Major injuries
Minor injuries
Global warming
na: not applicable
Burden
Impacts
Unit
per TWh
4.8e-2
1.82
mECU/kWh
6.0e-3
3.5e-3
1.5 - 55.7
CO2
Damages
ECU/t poll.
na
na
3.8 - 139
σg
A
A
C
4.5 Summary and interpretation of results
Table 4.Error! Unknown switch argument. Damages of the natural gas fuel cycle
POWER GENERATION
Public health
Mortality*- YOLL (VSL)
of which TSP
SO2
NOx
NOx (via ozone)
Morbidity
of which TSP, SO2, NOx
NOx (via ozone)
Accidents
Occupational health
Major accidents
Crops
of which SO2
NOx (via ozone)
Ecosystems
Materials
Noise
Visual impacts
Global warming
low
mid 3%
mid 1%
upper
OTHER FUEL CYCLE STAGES
Public health
Outside EU
Inside EU
Occupational health
Outside EU
Inside EU
Ecological effects
Road damages
Global warming
low
mid 3%
mid 1%
upper
mECU/kWh
σg
2.86 (10.8)
ng
0.95 (4.0)
1.8 (6.7)
0.11
0.54
0.35
0.19
nq
3.2e-2
nq
9.4e-2
2.8e-3
9.1e-2
ng
1.8e-2
nq
nq
B
A
B
A
A
B
B
B
C
1.5
7.2
18.5
55.7
1.8e-4
8.6e-5
8.9e-5
1.7e-2
1.4e-2
3.3e-3
nq
nq
A
A
B
A
C
2.4e-2
1.2e-1
3.0e-1
9.0e-1
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ExternE National Implementation. Spain
*Yoll= mortality impacts based on ‘years of life lost’ approach, VSL= impacts evaluated based on ‘value of
statistical life’ approach.
ng: negligible; nq: not quantified; iq: only impact quantified; - : not relevant
Table 4.Error! Unknown switch argument. Sub-total damages of the gas fuel cycle
YOLL (VSL)
low
mid 3%
mid 1%
upper
mECU/kWh
5.1 (13.0)
10.9 (18.8)
22.4 (30.3)
60.2 (68.1)
Table 4.Error! Unknown switch argument. Damages by pollutant
SO2 *- YOLL (VSL)
NOx *- YOLL (VSL)
PM10 *- YOLL (VSL)
NOx (via ozone)
CO2
ECU / t of pollutant
6392 (24163)
7849 (26796)
1500
3.8 - 139
*Yoll= mortality impacts based on ‘years of life lost’ approach, VSL= impacts evaluated based on ‘value of
statistical life’ approach.
As might be expected, damages from the gas fuel cycle are rather low, mainly due to the low
pollutant emission rates. In addition, it has to be noted that the site chosen for this power plant
is a sparsely populated one.
However, these damages are only low if global warming damages are excluded, or if they are
kept at their lowest range. When the upper estimate for these damages is considered, damages
reach 60 mECU/kWh, what is higher than the private costs of gas-generated electricity. Even
in this case, damages are lower than for coal or oil, mostly due to the higher conversion
efficiencies of gas fuel cycles, and therefore, their lower CO2 specific emission rates.
The impacts of upstream stages are also quite small, in spite of the long distance from which
gas is transported. This might be explained by the relatively good conditions in which this
transport is made, the pipeline being finished very recently. Would the gas come from other
source with worse engineering practices, or by ship instead of pipeline, it is expected that the
damages of the upstream stages would be larger.
74
5. BIOMASS/LIGNITES FUEL CYCLE
5.1 Definition of the biomass/lignites fuel cycle, technology and site
5.1.1 Technology description
The assessment of this fuel cycle will be based on a hypothetical 20 MW CFBC power plant,
which would be installed near Soria, in Northeastern Spain. The co-combustion of biomass
and lignites has been considered an interesting option because of the environmental
advantages that it may present, as well as for the use of domestic energy sources.
The fuel contribution will be of 40% of forest residues, and 60% of black lignites. The
extraction, transport and power generation stages have been analyzed, and are shown in the
following diagram.
Plant
construction
Forest residues
collection
Fuel transport
Power
generation
ELECTRICITY
Lignite extraction
Waste disposal
Plant
dismantling
Limestone extraction
and transport
Figure 5.Error! Unknown switch argument. Stages of the biomass/lignites fuel cycle
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ExternE National Implementation. Spain
5.1.1.1 Forest residues collection
Forest residues come from cleaning and thinning of existing pine forests in the area. This
cleaning and thinning currently produce more than 300,000 t of residues per year, which have
to be removed in order to prevent forest fires. Of them, 40,875 t will be used yearly as fuel for
the power plant.
Due to the alternative use of the residues, which would be burnt on the ground, and due to the
small proportion of them being used for the power plant, we will assume that this biomass is
CO2 free.
Since these residues would have been collected anyway, we will assume that the marginal
impacts of this stage, such as air emissions, or occupational accidents, are zero.
The average composition of the forest residues to be used is shown in the following table.
Table 5.Error! Unknown switch argument. Composition of forest residues
PROXIMATE ANALYSIS (%w dry basis)
Fixed carbon
21.41
Volatiles
75.56
Ashes
3.03
ULTIMATE ANALYSIS (%w dry basis)
Carbon
51.28
Oxygen
40.34
Hydrogen
4.69
Nitrogen
0.51
Sulphur
0.15
HEATING VALUE: 4678 kcal/kg dry basis
ASH ANALYSIS (%w dry basis)
SiO2
46.06
CaO
29.05
K2O
13.06
Al2O3
10.91
P 2O 5
5.27
MgO
4.73
Fe2O3
4.48
5.1.1.2 Lignite production
Black lignite will be extracted from open cast mines in Teruel. The black lignite resources of
the area are estimated to be around 300 Mt, of which the amount needed by the power plant,
61,460 t/yr represents a very small percentage.
The mining operation is common to other open air lignite exploitations. To extract the lignite
a first drilling and blasting is done in order to separate the topsoil that covers the lignite and
transport it to a refuse area. Then, lignite is extracted with diggers and transported to the
76
Biomass/Lignites Fuel Cycle
treatment area. The lignite treatment in the mine consists of crushing and screening processes
in order to separate the different lignite fractions from the refuse coal.
The principal characteristics of the lignites from the Teruel area are summarized in the
following table.
Table 5.Error! Unknown switch argument. General characteristics of black lignites from the
Teruel area.
PROXIMATE ANALYSIS (%w dry basis)
Fixed carbon
30.5
Volatiles
41.29
Ashes
28.21
ULTIMATE ANALYSIS (%w dry basis)
Carbon
48.76
Oxygen
10.07
Sulphur
9.86
Hydrogen
2.2
Nitrogen
0.9
HEATING VALUE: 4773 kcal/kg dry basis
ASH ANALYSIS (%w dry basis)
SiO2
37.4
CaO
18.48
Al2O3
18.35
Fe2O3
9.3
K2O
3.03
MgO
2.01
Na2O
1.42
The inputs needed for lignite extraction, and the outputs produced, are shown in the following
diagram.
61,460 t lignite/yr
35 workers
Occupational accidents
Mining equipment
LIGNITE EXTRACTION
Air emissions
47.31 t/yr TSP
2.94 t/yr NOx
0.34 t/yr SO2
52 t/yr CH4
121t/yr CO
0.36 t/yr VOC
160 t/yr CO2
Figure 5.Error! Unknown switch argument. Lignite extraction
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ExternE National Implementation. Spain
5.1.1.3 Fuel transport
Forest residues are normally transported as they are collected, in 5 to 24 t of capacity trucks.
The biomass needed to feed the power plant for a year will be around 40,000 tons. If it is
assumed that the larger trucks are used, the number of trips of these trucks to transport that
amount of biomass from the forests to the plant will be around 1,700. Taking into account the
forest residues production cited in section 5.1.1.1, the average transport distance for biomass
would be 25 km. Assuming 250 working days per year, and that a single truck may do two to
three trips per day, it would be necessary to have four trucks exclusively dedicated to the
biomass transport to the plant.
It will be assumed that 24 t trucks are also used for lignite transport. The load transported will
be of about 60,000 tons per year. As the average transport distance is 200 km, only one trip
per day is permited for a single truck. With similar assumptions that in the case of forest
residues, the number of trucks necessary for the lignite transport will be of 12.
The inputs and outputs of this stage are shown in the following figure.
14 workers
1,090,000 km
61,460 t lignite
61,460 t lignite
40,875 t biomass
Road
damages
FUEL TRANSPORT
Road
accidents
40,875 t biomass
Air emissions
292 t/yr CO2
0.46 t/yr TSP
5.40 t/yr NOx
0.39 t/yr SO2
1.40 t/yr VOC
6.42 t/yr CO
Figure 5.Error! Unknown switch argument. Fuel transport stage
5.1.1.4 Limestone extraction and transport
40,000 t of limestone are needed for the fluidized bed. This limestone will be extracted from a
quarry some 25 km away from the power plant. Its composition is shown in the following
table.
78
Biomass/Lignites Fuel Cycle
Table 5.Error! Unknown switch argument. Composition of the limestone
%w
CaCO3
93
MgCO3
5
Ash
2
Assuming a productivity for limestone extraction similar to that of an open cast mine, some
16 workers will be needed for the extraction of the amount needed for the power plant.
The limestone will be transported to the power plant by road, with a distance travelled of
90,000 km per year.
20 workers
90,000 km
Quarrying
equipment
40,000 t limestone
LIMESTONE EXTRACTION
AND TRANSPORT
Road
damages
Road
accidents
Air emissions
131 t/yr CO2
31.58 t/yr TSP
2.4 t/yr NOx
0.26 t/yr SO2
0.35 t/yr VOC
1.33 t/yr CO
34.7 t/yr CH4
Figure 5.Error! Unknown switch argument. Limestone extraction and transport
5.1.1.5 Power generation
The technology for the conversion of biomass and lignite into electricity that has been selected
is the fluidized bed combustion in a circulating fluidized bed combustor (CFBC). This
technology was selected because of the possibility that has of combusting non-homogeneus
fuels with different heating values, moisture content and particle size. The operational
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ExternE National Implementation. Spain
flexibility of fluidized bed boilers make them the most suitable option for the joint
combustion of fuels for which other standard boilers are not adequate.
Between the bubbling and the circulating fluidized bed boilers, it was selected the circulating
fluidized bed type because of its slightly higher efficiency acknowledged in the literature. For
the plant size considered, 20 MWe, the added complexity of the circulating boiler compared
to the bubbling type may be compensated by the increase in efficiency.
Biomass would be stored in a closed place to protect it from the rain and to favour its drying
process. Depending on their moisture content and the combustion conditions of the boiler,
forest residues could be stored for different periods of time. Normally, the climatic conditions
of the studied area permit short storing periods for a good biomass combustion. As forest
residues can be collected along the year, the storing place needs to have capacity to feed the
plant for approximately 15 days (around 2,000 tons of forest residues).
Lignites will be stored in stacks at open air. As in the case of biomass, it is necessary to
maintain a security pool, in case of supply contingencies, to feed the plant for at least 15 days.
This means approximately 3,000 tons of lignite.
The following figure shows a general scheme of the power plant.
BAGHOUSE
FILTER
BIOMASS
AND LIGNITE
STORAGE
FUEL
FEEDING
SYSTEM
STACK
STEAM
TURBINE
CIRCULATING
FLUIDIZED
BED
BOILER
20 MWe
CONDENSER
WATER
SUPPLY
WATER
TREATMENT
PLANT
COOLING
TOWERS
Figure 5.Error! Unknown switch argument. General scheme of the power plant
The high fluidizing velocity carries out the bed material into the recirculating cyclones. These
cyclones separate the majority of the solids which are then returned to the base of the
80
Biomass/Lignites Fuel Cycle
combustor through external heat exchangers. Most of the ash is removed from the base of the
combustor together with the inert material and the spent limestone, which has been
transformed into gypsum. The following table shows the composition of the spent bed
material and the fly ash. Ashes will be disposed in a landfill near the power plant.
The hot gases from the recirculation cyclones are used in a heat recovery steam generator
(HRSG) to produce the steam necessary to generate electricity in the water-steam cycle. After
the HRSG the gases from the CFBC are used to preheat the combustion air. The cooled gases
are passed through a baghouse filter to retain the particulates, and before being exhausted
through the stack.
To produce electricity, a conventional water-steam cycle of one pressure level without reheat
will be used. The steam is produced in the HRSG and the steam turbine inlet conditions are 80
bar and 520ºC. The gross electricity production will be 22.3 MW and there will be necessary
1.8 MW for ancillary consumption (solids reception, storage and handling, fans, pumps,
lighting, etc.). The net electricity production will be 20 MW and the overall plant efficiency
will be around 29%. There will be produced around 155,000 MWhel per year.
The steam turbine has facilities for steam extraction to allow for transfer of steam to the water
deaerator tank or other uses as the feedstock drying. The low pressure steam from the turbine
is condensed and pumped to the water preheaters that are normally placed in the recirculating
section of the CFBC, thus completing the steam cycle.
The condenser is cooled with water from the cooling towers. The water needed in the plant is
obtained from the river Mazo, that flows close to the plant location.
As was mentioned before, the CO2 emissions considered have been only those due to the
lignite combustion, since the biomass used is considered CO2-free.
The construction period will be around two years and the materials used are similar to the
ones used for the construction of a conventional power plant. Plant life is estimated to be 25
years. As it will be seen in later sections, the dismantling of the plant will be assumed to cause
similar impacts that the plant construction.
An input-output diagram of this stage is shown on the following figure.
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ExternE National Implementation. Spain
225 workers
(for two years)
10,000 t steel
35,000 t concrete
5,000 t cladding
and roofing
PLANT
CONSTRUCTION
Occupational accidents
Road damages
Air emissions
26 t SO2
4 t NOx
145 kg TSP
1085 t CO2
25 workers
277,118 m3 water
40,000 t limestone
PLANT
OPERATION
61,460 t lignite
40,875 t biomass
PLANT
DISMANTLING
Occupational accidents
150,000 MWh
3,022 t bottom ash
16,830 t fly ash
Air emissions
119,122 t CO2
34.5 t TSP
120 t SO2
60 t NOx
180 t CO
Occupational accidents
Road damages
10,000 t steel
35,000 t concrete
5,000 t cladding
and roofing
Air emissions
122 kg SO2
1989 kg NOx
145 kg TSP
107 t CO2
Figure 5.Error! Unknown switch argument. Power generation stage
5.1.1.6 Waste disposal
The main waste products produced along the fuel cycle are the ashes generated in the power
generation stage. These ashes will be disposed in a landfill sited very near to the power plant,
so the impacts produced by the ash transport are expected to be negligible.
5.1.2 Site description
5.1.2.1 Geographical location
The place chosen for the installation of the biomass power plant is the municipality of
Almazán, in the province of Soria, in Northeastern Spain. The site is 20 km south from the
capital (Soria) and 154 km to the Northeast of Madrid. Error! Unknown switch argument.
shows the location within the region of Castilla-León and Spain.
82
Biomass/Lignites Fuel Cycle
CASTILLALEÓN
SORIA
Almazán
Madrid
Figure 5.Error! Unknown switch argument. Situation of Almazán within the province of
Soria, the region of Castilla-León and Spain.
The site proposed for the location of the power plant is in the 206th km of the trunk road
Medinaceli-Soria (N-111), 14 km away from the city of Almazán and 20 km away from the
capital of the province, Soria.
The coordinates of the site chosen in the municipality of Almazán are:
Latitude:
41º 36’19’’ N
Longitude:
2º 30’ 03’’ W
Altitude:
1,100 m
UTM co-ordinates:
x = 542.500
y = 4,606.100
5.1.2.2 Topography
The topography of the province of Soria is dominated by areas over 1,000 metres high,
covering more than 70% of the total province area. As in the province of Soria, in the
reference area (local level of study) most of the land has heights over 1,000 m. Only two
different parts, one in the Northeast and the other in the Southeast, are lower than 800 m. An
important area in the Northwest of the reference area has heights over 2,000 m. This area
belongs to the Sierra de Urbión and Sierra Cebollera.
The following figure shows the topography of the area.
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ExternE National Implementation. Spain
Figure 5.Error! Unknown switch argument. Topography of the local area studied
5.1.2.3 Hydrology
Two main watersheds may be found in the area studied, those of Duero and Ebro rivers.
The watershed of river Duero is regulated by the Cuerda del Pozo reservoir, located in the
Northwest of the reference area of study, and by two initial influents, river Revinuesa and
river Ebrillos. Near Soria, the river Duero receives the flows of river Tera and river
Merdancho.
Between the city of Soria and the border of the province, the most important influents of river
Duero are:
• from the left margin, river Rituerto-Araviana, which crosses the Campo of Gomara, the
Torete-Escalote, the Retortillo-Talegones, the Tiermes-Caracena and finally river Pedro,
and
• from its right margin, the short rivers Mazo, Izana and Fuentepinilla, and in the location of
La Rasa the most relevant influent of the province, the system of river Ucero (with its
tributaries Sequillo, Abión and Lobos) just in the west border of the reference environment
of the power plant.
The Ebro basin is located in the reference environment, as can be noted in the above figure, in
two different areas:
84
Biomass/Lignites Fuel Cycle
• In the Northeast by the heads of the rivers Cidacos, Mayor or Linares, Alhama, Fuentestrún
and Queiles. The last two are partially artificial, so river Fuentestrún is the result of
Añavieja Lake dewatering and river Queiles, remarkably in its channel between Olvega and
Agreda, is a part of works which attempt to improve the water utilisation in an area with
water needs for a long time ago.
• River Jalón basin, in the Southeast of the reference area, has in its fountain head two
significant influents, the rivers Nágima and Henar.
The management of aquifers in the province of Soria is not very relevant, but they are
sizeable. There are three different systems: Southeast Tertiary, Mesozoic Karstic and West
Jurassic of Soria (eminently around Moncayo). Commonly, water quality is good, but there is
certain pollution by nitrates in the Southeast Tertiary (more problematic in Campo de
Gómara) (Junta de Castilla y León, 1988).
5.1.2.4 Climatology
Climate in this region may be defined as continental, with hard winters and warm summers.
Mean temperatures range from 2.3ºC in January to 19.6ºC in July. Temperatures over 20ºC
only appear in areas below 900 m height, which is a small part of the local area. There is a
clear relationship between altitude and temperature, with the latter decreasing 1ºC per each
100 m height increment.
Rainfall is moderate, around 550 mm per year, being quite regular along the year. The highest
rainfall occur in the north, in the mountain ranges.
Wind blows predominantly from the west and north.
In the following table, the average meteorological data for the Soria observatory (20 km away
from the power plant), for 40 years, are shown.
Table 5.Error! Unknown switch argument. Meteorological data.
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Year
Rainfall (mm.)
48.5
47.4
46.9
49.4
57.7
52.7
29.5
28.7
44.4
43.9
53.8
51.7
554.6
Mean temperatures (ºC)
2.3
3.5
6.6
8.9
11.9
16.5
19.6
19.5
16.4
11.0
6.2
3.1
10.5
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ExternE National Implementation. Spain
5.1.2.5 Land use
General distribution
The agricultural character of the area studied can be concluded from the data contained in the
following table. As this table shows, more than 80% of total surface is covered by crops and
forests.
Table 5.Error! Unknown switch argument. General distribution of lands in the reference
environment (1993).
Type of surface
Herbaceous crops
Fallow lands
Tree crops
TOTAL CROPS
Grasslands
Pastures
TOTAL GRASSLANDS AND PASTURES
Timber forest
Open forest
Shrub forest
TOTAL FOREST
Uncultivated
Esparto field
Improductive
Non-agricultural
Rivers and lakes
TOTAL OTHER SURFACES
TOTAL MUNICIPAL SURFACE
(Ha.)
247,876
86,539
3,698
338,113
16,601
107,585
124,186
158,662
50,459
88,863
297,984
145,744
187
19,500
25,405
8,228
199,064
959,347
(%)
25.8
9.0
0.4
35.2
1.7
11.2
12.9
16.5
5.3
9.3
31.1
15.2
0.0
2.0
2.6
0.9
20.7
100.0
The contribution of forest surface in this area (31% of total surface) is higher than in CastillaLeón and in the rest of Spain.
Crops
Error! Unknown switch argument. displays the list of the most important crops in the
reference area of study, their surface, production and value of production. Finally, the last two
columns show the comparison between surface and value of each crop.
86
Biomass/Lignites Fuel Cycle
Table 5.Error! Unknown switch argument. Distribution of crop surfaces in the reference area
(1993).
CROP
Barley
Wheat
Sunflower
Alfalfa
Potato
Clover
Asparagus
Sugar beet
Other crops
Total
Surface
(ha)
118,989
75,143
38,199
1,493
650
2,413
312
718
13,589
251,506
Production
Price
(kg)
(ECU/kg)
240,259,608
0.14
153,971,500
0.17
40,591,950
0.38
55,700,000
0.09
16,322,786
0.17
29,956,356
0.09
1,374,940
1.29
36,381,764
0.04
46,367,366
620,926,270
Value
% of total
(ECU)
surface
33,068,459
47.3
25,829,886
29.9
15,380,659
15.2
5,249,303
0.6
2,724,421
0.3
2,723,305
1.0
1,772,839
0.1
1,591,978
0.3
9,477,129
5.4
97,817,979
100
% of total
value
33.8
26.4
15.7
5.4
2.8
2.8
1.8
1.6
9.7
100
As can be observed, the agriculture production in this area is mainly focused on cereals
(barley and wheat provide more than 75% of crop surface and more than 60% of total value of
crop production). If barley, wheat and sunflower are jointly contemplated, their area is over
92% and their value is over 75% of total crop production.
Forests
The total forest acreage in the local area studied is 297,984 ha. This area is divided into those
forests usually exploited, and those not usually exploited. This distribution is shown in the
following figure.
Low forest
6%
Not exploited
25%
Medium forest
10%
Timber forest
59%
Figure 5.Error! Unknown switch argument. Forest distribution in the local area
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ExternE National Implementation. Spain
Ecosystems
There are six significant natural ecosystems in the area, illustrated briefly in the following
paragraphs.
1. Black lagoon: This natural enclave, located in Sierra de Urbión, in the Northwest of the
area, is a sample of an old glacier present in this zone.
2. River Lobos Canyon: Vegetation in this natural park is very important, especially by Pinus
laricio and Juniperus. Fauna is very interesting too, particularly great raptors.
3. Fuentona flowing: River Abión emerges in this flowing located next to Muriel de la Fuente.
It is an interesting natural enclave.
4. Sabinar de Calatañazor: In this natural enclave, near river Duero, forest of Juniperus is
abundant. This type of tree is usually used for pasture.
5. Somolinos lagoon: This natural enclave is a small lagoon, originated from a natural CaCO3
barrage.
6. Gorges of Mesa: This depth canyon is formed by the river Mesa. The bottom of this natural
enclave is occupied by orchards.
5.1.2.6 Population
The total population of the reference area is 98,717 inhabitants, most of them living in small
municipalities (smaller than 1000 inhabitants). The municipalities comprised within the area
studied number 181, belonging 2 to La Rioja, 3 to Burgos, 14 to Zaragoza, 16 to Guadalajara,
and 156 to Burgos.
The main population centres are Soria, with 33,317 inhabitants, Almazán, with 6,012
inhabitants, and Burgo de Osma, with 5,011 inhabitants.
Distribution of population according to age is shown in Error! Unknown switch argument..
It displays a great presence of elderly in the reference environment and less importance of
population under 15 years.
Table 5.Error! Unknown switch argument. Population according to age in the area (1991).
Age group
Population
(%)
<5
4,147
4
5 - 14
10,716
11
15 - 64
62,039
63
> 65
21,815
22
Total
98,717
100
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Biomass/Lignites Fuel Cycle
The population density in the area studied is 9.8 inhab/km2, but with important differences
between areas. So, in most of the areas, population density is always below 10 inhab/km 2,
while around the municipality of Soria is located the highest populated area, with a density of
337 inhab/km2. Other important areas are located around Almazán (62 inhab/km2) and Burgo
de Osma (50 inhab/km2). The contrary can be found in other areas like Caracena (0.1
inhab/km2).
5.1.2.7 Transport network
As can be observed in the next figure, the road network in the province of Soria is not well
developed. From the site selected to install the biomass power plant, the nearest road is N-111
which links Pamplona with Medinaceli through Soria and Almazán. In the reference area this
road crosses from north to south until it connects with the trunk road N-II, which links the
cities of Madrid and Barcelona. The road N-122 crosses the province from west to Northeast
through Burgo de Osma, Soria and Agreda. Other relevant road is N-234 which connects
Soria and Burgos through the Northwest of the province.
4656
4646
C-115
4636
Agreda
4626
N-234
4616
N-122
y UTM coordinates
N-122
SORIA
C-101
4606
N-111
Gómara
Burgo de Osma
4596
C-101
Almazán
C-116
4586
C-116
4576
C-101
N-111
4566
N-II
4556
492
502
512
522
532
542
552
562
572
582
592
x UTM coordinates
Figure 5.Error! Unknown switch argument. Road network in the province and in the
reference area.
89
ExternE National Implementation. Spain
5.2 Overview of burdens
As for other fuel cycles based on combustion, the major burdens of the biomass/lignites fuel
cycle arise from the power generation stage, from the atmospheric emissions generated in it.
Lignite extraction also produces significant burdens such as atmospheric emissions and
occupational accidents. No burdens have been taken into account from the forest residues
collection, since it has been considered that this activity would have taken place even if this
fuel cycle were not implemented.
Due to the relatively low density of the fuels used, the amount of km to be traveled (1,090,000
km/yr) by road is also an important burden of this fuel cycle.
5.2.1 Atmospheric emissions
The main producers of atmospheric emissions are the mining and power generation activities,
although the first one is only relevant for particulate matter. The air pollutants considered
have been PM10, NOx, SO2, and CO2. For some stages, some information on CH4, CO, or
VOCs as available, and so it has been taken into account.
Table 5.Error! Unknown switch argument. Atmospheric emissions of the biomass/lignites
fuel cycle (g/MWh)
2. Lignite extraction
3. Fuel transport
4. Limestone extraction
and transport
5. Power generation
TOTAL
nd : not determined
PM10
315
3.1
211
SO2
2.3
2.6
1.7
NOx
2.0
36
16
CO2
1067
1947
873
CO
347
nd
231
VOC
2.4
9.3
2.3
230
759
800
807
400
472
794,147
798,034
nd
578
nd
14
As may be seen, the bulk of atmospheric emissions correspond to the power generation stage,
except for particulate emissions, which are produced mainly at the extraction stage, because of
the large amounts of fugitive dust released.
5.2.2 Liquid effluents
As was already mentioned for the coal fuel cycle, the mining of lignites requires draining large
amounts of water, which has to be treated before it is released. In addition, sometimes lignites
are washed to reduce their sulphur content, creating alkaline waters. However, for the case
studied, no data were available.
The same goes for the water requirements of the power plant, due mainly to the cooling
system needs.
90
Biomass/Lignites Fuel Cycle
5.2.3 Solid wastes
Solid wastes are produced mainly during the lignite extraction and power generation stages.
The major one is gypsum, produced when treating the drainage water from the mine, and
when washing the lignites, and also in the fluidized bed of the boiler. However, no data are
available for determining the amount of gypsum produced.
The only data for solid wastes refer to ash production, of which 19,850 t are produced
annually.
5.2.4 Occupational accidents
Occupational accidents are a significant burden for the mining stage. However, it has to be
noted that the accident rate used here is the one for the whole mining sector in Spain, which
is composed mainly of underground mines. For open-cast mines like the one being studied,
accident rates should be lower.
Table 5.Error! Unknown switch argument. Occupational accidents per TWh
2. Lignite extraction
4. Limestone extraction
and transport
5. Power generation
nd : not determined
Fatal accidents
1.7e-1
5.3e-2
Major injuries
2.7e-1
2.4e-1
Minor injuries
85.6
1.2e-1
5.6e-2
0.35
14.4
5.3 Selection of priority impacts
For the assessment of this fuel cycle, both the impacts of the biomass and lignites fuel cycle
will have to be taken into account. Error! Unknown switch argument. shows the impacts
considered in this fuel cycle.
Table 5.Error! Unknown switch argument. Impacts of the biomass/lignite fuel cycle.
Impacts
Mining/
Transport Generation Waste disposal Construction
Collection
Global warming
x
x
x
x
x
Public health
x
x
x
x
Occupational health
x
x
x
x
Crops
x
x
x
Forests
x
x
x
Ecosystems
x
x
x
x
Materials
x
x
x
Noise
x
x
x
x
Road traffic
x
x
Fire risk
x
Resettlement
x
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ExternE National Implementation. Spain
Impacts
Visual impact
Mining/
Collection
x
Transport
Generation
Waste disposal
Construction
x
x
x
The expected major impact is that caused by the atmospheric emissions of the generation
stage on crops, forests and ecosystems, materials and global warming. Regarding the latter,
the previous CO2 fixation by biomass will be considered.
Another important impact of the cycle is that caused by the washing of lignites on water
quality, although this one is quite difficult to assess.
Biomass transport is also expected to cause road damages, which will be also estimated. Other
impacts, such as noise, or visual impact, due to their local nature, are not expected to be
significant.
So, the priority impacts that will be assessed are:
• Public health,
• Occupational health,
• Crops,
• Forests,
• Ecosystems,
• Materials,
• Road damages, and
• Global warming.
5.4 Quantification of impacts and damages
5.4.1 Lignite extraction
Lignite extraction produces several environmental and health impacts. The major ones are the
effects on miners health, and also water and soil pollution from the mining activities.
However, most of these impacts are very difficult to quantify, due to the lack of appropriate
data. In the case of water and soil pollution, this is further complicated by the little knowledge
existing of water and soil impact pathways.
The impacts on miners health are expected to be not so great, since the incidence of
occupational diseases such as cancer or pneucomoniosis is not so high in open-cast mines
such as those considered for this fuel cycle. Therefore, only occupational accidents have been
taken into account.
92
Biomass/Lignites Fuel Cycle
Atmospheric pollution from mining activities has been estimated, in order to assess its
impacts. These impacts are expected to be negligible, except for GHG emissions, since the
emissions of this stage make up for a very small percentage of the total emissions of the fuel
cycle. This is not the case for TSP emissions, which are around half of the total emissions.
However, the diameter of most of the particulates contained in this measure is larger than
10µm, so the real PM10 emissions will be much smaller. Moreover, these particulates are
emitted from a very low height, thus being dispersed in a reduced area, and affecting mostly
mine workers.
The visual impact of open-cast mines, and its alteration of the environment, although relevant
at a local scale, are not expected to be significant when compared to the regional effects of the
fuel cycle.
Table 5.Error! Unknown switch argument. Impacts and damages of lignite extraction
Impact
Occupational accidents
Deaths
Major injuries
Minor injuries
Global warming
Burden
Impacts
Damages
Unit
per TWh mECU/kWh
ECU/t poll.
1.7e-1
2.7e-1
85.6
CO2
CH4
0.4
3.3e-2
1.6e-1
4e-3 - 1.5e-1
2.8e-2 - 1.0
na
na
na
3.8 - 139
81 - 2975
σg
A
A
A
C
C
na: not applicable
5.4.2 Fuel transport
Due to the relatively low energy density of the fuels used for this fuel cycle, the transport stage
will be more significant, regarding its damages, than for other fuel cycles assessed before.
The main impact within this stage is the damages caused to roads. However, it has to be
reminded that this damage may be already internalized, in some cases, through road taxes. The
impact of road accidents is also important, although smaller.
As for the atmospheric emissions of the vehicles, its impact has been considered negligible,
due to its very small contribution to the total fuel cycle emissions. Only greenhouse gas
emissions have been taken into account, due to their global nature.
Table 5.Error! Unknown switch argument. Impacts and damages of fuel transport
Impact
Road accidents
Deaths
Major injuries
Minor injuries
Road damages
Global warming
na: not applicable
Burden
Impacts
Damages
Unit
per TWh mECU/kWh
ECU/t poll.
6.0e-2
1.6e-1
3.0e-1
km
traveled
CO2
repair
costs
σg
0.16
2.0e-2
5.7e-4
0.3
na
na
na
na
A
A
A
A
7e-3 - 2.7e-1
3.8 - 139
C
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ExternE National Implementation. Spain
5.4.3 Limestone extraction and transport
The major impact of this stage is that produced by road accidents. As has been done for other
stages, the impact of atmospheric emissions is considered negligible because of its small share
of total emissions. The case of TSP emissions is similar to the lignite extraction stage, and so
it is not considered either. The same goes for local impacts, such as visual impact or
environment alterations, of the physical presence of the quarry.
Table 5.Error! Unknown switch argument. Impacts and damages of limestone extraction and
transport
Impact
Occupational accidents
Deaths
Major injuries
Minor injuries
Road accidents
Deaths
Major injuries
Minor injuries
Road damages
Global warming
Burden
km
traveled
CO2
CH4
Impacts
Unit
per TWh
repair
costs
mECU/kWh
Damages
ECU/t poll.
σg
5.3e-2
2.4e-1
1.2e-1
0.14
3.0e-2
2.3e-4
na
na
na
A
A
A
4.9e-3
1.3e-2
5.2e-2
1.3e-2
1.6e-3
9.9e-5
4.1e-2
na
na
na
na
A
A
A
A
3e-3 - 1.2e-1
1.9e-2 – 6.9e-1
3.8 - 139
81 - 2975
C
C
na: not applicable
5.4.4 Power generation
The largest share of the damages of power generation stage belongs to health effects caused by
the atmospheric emissions of the power plant, and to the global warming produced by GHG
emissions.
Second in importance are occupational accidents (which may be internalized to a certain
extent), and damages on materials. Effects on crops and forests are much smaller, although it
has to be reminded that, for crops, only some of them, which are not the most valuable crops
in Spain, are taken into account. The introduction of horticultural or tree crops would certainly
rise the damages on crops.
Impacts of water pollution have not been assessed, although they might be significant.
94
Biomass/Lignites Fuel Cycle
Table 5.Error! Unknown switch argument. Impacts and damages of power generation
Impact
Human health
Chronic YOLL
Acute YOLL
Morbidity
Crops
Ecosystems
Materials
Occupational accidents
Deaths
Major injuries
Minor injuries
Road damages
Global warming
Burden
TSP
Nitrates
Sulfates
SO2
Ozone
Nitrates
Ozone
SO2
CO
Sulfates
TSP
SO2
Ozone
N dep.
Impacts
Unit
per TWh
years
years
years
years
2.02e+1
4.04e+1
6.26e+1
7.20e-1
cases
2.49e+3
cases
cases
cases
cases
dt yield loss
2.75e-1
6.30e+1
3.86e+3
1.25e+3
4.82e+5
kg fertilizer
added
Ac. dep.
kg lime
added
N dep.
km2 exceed.
area
SO2
km2 exceed.
area
NOx
km2 exceed.
area
m2 maint.
SO2
area
km
traveled
CO2
repair costs
mECU/kWh
Damages
ECU/t poll.
σg
-2.97e+4
1.70
3.40
5.28
1.12e-1
1.65e-1
4.37e-1
2.93e-1
2.16e-3
4.96e-1
6.57e-1
2.19e-1
2.19e-2
1.40e-1
-5.10e-4
7510
8570
6590
139
412
1100
732
2.70
410
822
964
27.3
350
na
B
B?
B
B
B
A-B?
B
A-B
B
A-B
A-B
A
B
A
5.10e+5
8.75e-3
na
A
0
na
0
0
na
0
0
na
0
4.46e+3
7.52e-2
94
B
5.6e-2
0.35
14.4
0.15
4.3e-2
2.8e-2
6.1e-3
na
na
na
na
A
A
A
A
3.0 - 111
3.8 - 139
C
95
ExternE National Implementation. Spain
na: not applicable
5.5 Summary and interpretation of results
Table 5.Error! Unknown switch argument. Damages of the biomass/lignites fuel cycle
POWER GENERATION
Public health
Mortality*- YOLL (VSL)
of which TSP
SO2
NOx
NOx (via ozone)
Morbidity
of which TSP, SO2, NOx, CO
NOx (via ozone)
Accidents
Occupational health
Major accidents
Crops
of which SO2
NOx (via ozone)
Ecosystems
Materials
Noise
Visual impacts
Global warming
low
mid 3%
mid 1%
upper
96
mECU/kWh
σg
10.7 (41.4)
1.7 (6.3)
5.4 (22.4)
3.4 (12.5)
0.17
1.6
1.4
0.27
nq
0.17
nq
0.15
1.4e-2
0.14
ng
7.5e-2
nq
nq
B
A
B
A
A
B
B
B
C
3.0
14.3
36.5
111.4
Biomass/Lignites Fuel Cycle
OTHER FUEL CYCLE STAGES
Public health
Occupational health
Ecological effects
Road damages
Global warming
low
mid 3%
mid 1%
upper
0.20
0.76
nq
0.34
A
A
B
A
C
6.2e-2
0.29
0.75
2.23
*Yoll= mortality impacts based on ‘years of life lost’ approach, VSL= impacts evaluated based on ‘value of
statistical life’ approach.
ng: negligible; nq: not quantified; iq: only impact quantified; - : not relevant
Table 5.Error! Unknown switch argument. Sub-total damages of the biomass/lignites fuel
cycle
YOLL (VSL)
low
mid 3%
mid 1%
upper
mECU/kWh
17.2 (47.9)
28.7 (59.4)
51.6 (82.3)
127.2 (157.9)
Table 5.Error! Unknown switch argument. Damages by pollutant
SO2 *- YOLL (VSL)
NOx *- YOLL (VSL)
PM10 *- YOLL (VSL)
NOx (via ozone)
CO2
ECU / t of pollutant
7113 (28363)
9600 (32350)
8348 (28174)
1500
3.8 - 139
*Yoll= mortality impacts based on ‘years of life lost’ approach, VSL= impacts evaluated based on ‘value of
statistical life’ approach.
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ExternE National Implementation. Spain
As may be seen, damages per t of pollutant emitted are higher for this site than for the one
chosen for the coal fuel cycle. However, damages per kWh are lower. This is explained by the
lower emission factors produced by both the technology and the fuel mix chosen.
In spite of the very high sulphur content of the lignites used, the participation of biomass
reduces significantly the damages caused by SO2 emissions. The CO2-neutral character of
biomass also contributes to lower net CO2 emissions. Both reductions produced damages
which are lower than, for example, those of the coal fuel cycle assessed previously, which
used good-quality coal, and modern technologies.
Results show, then, the advantages of co-firing biomass with lignites. It seems then that
biomass could have a significant role in energy generation if electricity generation from
lignites, and at the same time, pollution reduction is attempted. This would only be true,
however, if biomass fuels are exploited on a sustainable way, and if they are transported from
short distances, so that the biomass fuel cycle would retain its carbon-neutral character, and
pollutant emissions of the fuel cycle are kept small.
98
6. WIND FUEL CYCLE
6.1 Definition of the wind fuel cycle, technology and site
6.1.1 Technology description
The fuel cycle is characterized by all stages of processing energy, from fuel extraction, to
distribution to consumers. However, the wind fuel cycle appears different, as it has only two
stages, generation and distribution.
This requires a different treatment compared to other fuel cycles. In those, no life cycle
analysis is carried out, as the main impacts result from the operational stage, and thus, not
considering the rest of the cycle does not remarkably affect results. However, for wind energy,
impacts are distributed along the entire life cycle, and not accounting for stages other than
operation would lead to a large underestimation of impacts. For example, atmospheric
emissions appear not in the operational stage, but in the construction of the turbines, and are
likely to be of the same magnitude as impacts more characteristic of the wind fuel cycle, such
as noise and visual amenity.
Therefore, the stages to be considered are the following:
Resource extraction
Turbine manufacturing
Turbine operation
Decommissioning
Product disposal
Figure 6.Error! Unknown switch argument. Stages of the wind fuel cycle
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ExternE National Implementation. Spain
These stages will be condensed into two: turbine construction and turbine operation. The rest
are assumed to produce negligible impacts when compared to these.
The wind farm that will be assessed is a 3 MW wind farm located in Camariñas, in the
Northwestern corner of Spain. The wind farm has 20 MADE AE/20 wind turbines in
operation, plus other three turbines for experimentation purposes.
6.1.1.1 Turbine construction
As said before, the wind turbines operating at the Cabo Vilano wind farm are MADE AE/20,
developed and manufactured by the Spanish company MADE.
These are three-bladed, 150 kW wind turbines, with stall control, asynchronous generator, and
steel, cylindrical towers. Its main characteristics are shown in the following table.
Table 6.Error! Unknown switch argument. Characteristics of MADE AE/20 wind turbines
Rated power
150 kW
Rotor diameter
20 m
Rotor speed
46 rpm
Rated wind speed
14 m/s
Tower height
21/28 m
Weight
16.3 t
According to the life cycle analysis approach, it is required to know the energy and material
requirements of this stage. for this, material weights have been estimated from existing studies
(Schmid et al, 1990). The energy required to manufacture these materials, and the CO2
emissions lied to it, have been estimated based on Spanish industrial energy consumption,
transforming thermal energy to electricity (except for glass fibre, which data are taken from
the original EC report (EC, 1995)).
All these data are summarized in the following diagram, for the whole wind farm.
100
Wind Fuel Cycle
1,587 MWh
20 AE/20 wind turbines
26.6 t glass fibre
3.7 t copper
321 t steel
352 t concrete
TURBINE
CONSTRUCTION
542 t CO2
Occupational
accidents
Figure 6.Error! Unknown switch argument. Turbine construction
6.1.1.2 Turbine operation
The wind farm generated in the last year some 5,270 MWh, with a capacity factor of 0.3.
The noise level produced by the wind turbines has been estimated to be around 105 dB, based
on measurements taken from similar turbines.
No operation accidents have been reported for this stage in the wind farm. However, road
accidents may be expected due to the increment in road traffic by the wind farm workers.
The operating and maintenance staff is 2, with a round trip journey of 138 km for one of them,
and 7 km for the other, for 240 days a year.
In addition, 2 technicians come once a year from 526 km away, for maintenance.
6.1.2 Site description
The wind farm selected for this study was installed in Cabo Vilano in 1992. Cabo Vilano is
within the municipality of Camariñas, province of La Coruña, at the Northwestern corner of
Spain.
The site is about 1 km away from Cabo Vilano lighthouse, in a flat plateau completely cleared
of vegetation, some 50 to 100 m above sea level, and at 250 m distance from the seashore.
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ExternE National Implementation. Spain
It is a very sparsely populated area, with 4,123 people living in the two municipalities from
where the wind farm may be seen, Camariñas (3 km away from the wind farm) and Muxía (at
5 km distance across the ría de Camariñas). A view of the wind farm is shown in the
following figure.
Figure 6.Error! Unknown switch argument. Cabo Vilano wind farm
The area shows very high wind speeds (around 8 m/s yearly average), mostly from the sea
(NE and SSW). This prevents the existence of trees. However, the area is considered to have
relevant ecological characteristics, and is one important tourist attraction in Galicia.
In spite of the very high wind potential of the area (around 600 MW), few wind farms have
been installed, and so the pressure on the ecosystem and on the landscape is not considered yet
to be significant.
6.2 Overview of burdens
First of all, it has to be noted that wind energy should be considered a low-impact technology,
and so it is quite difficult to point at any of its burdens as a significant one.
102
Wind Fuel Cycle
Noise is always identified as a major burden of wind energy, although in this case, it is not
expected to be significant, as the wind farm is far from population centres. This is also the
reason why the physical presence of the wind farm is not an important burden for this case.
This physical presence should not be a burden neither for bird population, which seem to have
got used to the wind farm.
The only major burden which might be identified is the amount of km traveled by the O&M
staff, which is quite high, and might produce road accidents to a certain extent.
6.3 Selection of priority impacts
The impacts expected to be produced by the wind fuel cycle are presented in the following
table.
Table 6.Error! Unknown switch argument. Impacts of the wind fuel cycle
Impacts
Turbine
Power
manufacturing
generation
Global warming
x
Public health
x
Occupational health
x
Crops
x
Forests
x
Ecosystems
x
x
Materials
x
Noise
x
Impact on birds
x
Electromagnetic
x
interferences
Visual impact
x
Most of these impacts will be assessed, except for impacts on birds, or electromagnetic
interferences, which are expected to be not significant.
Impacts on birds have been found to be negligible, according to the Environmental Impact
Analysis carried out for the wind farm (Lago et al, 1993). The resident bird species seem to
have got used to the farm, and there is no migratory route crossing it.
As for electromagnetic interferences, the area affected is confined to a very small region (less
than 1 km2) around the wind turbines. Its effect is considered negligible.
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ExternE National Implementation. Spain
6.4 Quantification of impacts and damages
6.4.1 Turbine construction
The major impacts of this stage are those caused by the atmospheric emission of pollutants.
Since the major impact of these pollutants is produced on human health, only these effects
have been considered. Monetary estimates of the damages have been obtained from the
aggregation exercise carried out for the Spanish electricity sector (see section 8).
The occupational accidents for this stage have been estimated based on the rates provided by
the EC report (European Commission, 1995f), and on Spanish accident rates for construction.
These accidents comprise both those expected during manufacturing of the wind turbines and
the construction of the wind farm.
Impacts have been annualized assuming a lifetime of 20 years for the wind farm.
Table 6.Error! Unknown switch argument. Impacts and damages of turbine construction
Impact
Occupational accidents
Deaths
Major injuries
Minor injuries
Energy consumption
Global warming
na: not applicable
Burden
energy
use
CO2
Impacts
Damages
Unit
per TWh mECU/kWh
ECU/t poll.
MWh
1.1e-2
9.3e-1
5.8
15,057
σg
2.9e-2
1.2e-1
1.1e-2
5.7e-1
na
na
na
na
A
A
A
B
2e-2 - 7.2e-1
3.8 - 139
C
6.4.2 Turbine operation
Visual impact is usually cited as the largest impact of wind farms. In this case, however, it is
doubtful whether this impact really exists, as the wind farm is highly considered in the area,
having become a sort of tourist attraction. Therefore, its visual impact, if it exists, has been
considered to be negligible.
As for noise impacts, they are also quite small, because of the low population density of the
area surrounding the wind farm.
Occupational accidents are also expected to be negligible. However, some damages have been
estimated due to road accidents created by the transport of the staff.
104
Wind Fuel Cycle
Table 6.Error! Unknown switch argument. Impacts and damages of turbine operation
Impact
Road accidents
Deaths
Major injuries
Minor injuries
Noise
Visual amenity
na: not applicable
Burden
Impacts
Damages
Unit
per TWh mECU/kWh
ECU/t poll.
3.2e-1
8.5e-1
3.9
8.3e-1
1.1e-1
7.4e-3
8e-3
<0.001
na
na
na
na
na
σg
A
A
A
B
B
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ExternE National Implementation. Spain
6.5 Summary and interpretation of results
Table 6.Error! Unknown switch argument. Damages of the wind fuel cycle
POWER GENERATION
Public health
Mortality*- YOLL (VSL)
of which TSP
SO2
NOx
NOx (via ozone)
Morbidity
of which TSP, SO2, NOx, CO
NOx (via ozone)
Accidents
Occupational health
Major accidents
Crops
of which SO2
NOx (via ozone)
Ecosystems
Materials
Noise
Visual impacts
Global warming
low
mid 3%
mid 1%
upper
OTHER FUEL CYCLE STAGES
Public health
Occupational health
Ecological effects
Road damages
Global warming
low
mid 3%
mid 1%
upper
mECU/kWh
σg
ng
B
ng
ng
0.95
nq
ng
ng
ng
8e-3
ng
A
B
A
A
B
B
B
C
ng
ng
ng
ng
nq
0.16
ng
nq
A
A
B
A
C
2.0e-2
9.3e-2
2.4e-1
7.2e-1
*Yoll= mortality impacts based on ‘years of life lost’ approach, VSL= impacts evaluated based on ‘value of
statistical life’ approach.
ng: negligible; nq: not quantified; iq: only impact quantified; - : not relevant
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Wind Fuel Cycle
Table 6.Error! Unknown switch argument. Sub-total damages of the wind fuel cycle
YOLL (VSL)
low
mid 3%
mid 1%
upper
mECU/kWh
1.7 (1.7)
1.8 (1.8)
1.9 (1.9)
2.4 (2.4)
Damages of the wind fuel cycle are really small, as might be expected. Indeed, the largest
damages correspond to occupational accidents, which should be internalized to a certain
extent.
Those impacts most characteristic of this fuel cycle, such as noise or visual amenity, are quite
small in this case, due to the good siting of this wind farm, far from population centres and
from ecologically-sensitive areas.
These damages could be greater for wind farms installed nearer to population centres, or on
migratory routes, such as those in Tarifa. Therefore, great care should be taken for the future
wind energy deployment in Spain. Indeed, given the local nature of the impacts of the wind
fuel cycle, it may be shown that most of the impacts may be corrected from the planning
stage.
107
7. WASTE INCINERATION
7.1 Definition of the waste incineration cycle, technology and site
7.1.1 Technology description
The waste incineration process to be analyzed will be based on a real MSW plant located in
Mataró, near Barcelona. The plant has an integral treatment of residues, that is, there is a
recycling and composting stage, and the refuse is then burnt for electricity production. It has
an installed power of 11.6 MW, producing some 65,000 MWh of electricity per year. The
amount of residues treated by the plant is 170,000 t, of which 86% are incinerated.
The stages of the treatment process are shown in the following diagram.
PLANT
CONSTRUCTION
Recycling
Cardboard
Glass
Plastic
Non-ferrous metals
Magnetic scrap
PVC
14%
RESIDUES
Composting
MSW
transport
86%
Compost
ELECTRICITY
Incineration
Transport
PLANT
DISMANTLING
Ash
Figure 7.Error! Unknown switch argument. Stages of the waste incineration process
Each of these stages is characterized in the following sections.
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ExternE National Implementation. Spain
7.1.1.1 MSW transport
170,000 t of residues are transported yearly to the power plant from the Maresme region.
Every day, about 115 lorries arrive to the plant, involving the work of some 115 drivers. The
average distance travelled is 40 km per day and truck, what makes a total annual distance of
1,380,000 km.
As for the composition of the MSW, it is shown in the following table.
Table 7.Error! Unknown switch argument. Typical composition of MSW of the Maresme
region.
Type of residue
% in weight
Organic matter
45
Paper and cardboard
20
Glass, wood and metals
10
Plastic and fiber
25
An input-output diagram of this stage is shown in the following figure.
115 workers
170,000 t MSW
1,380,000 km
MSW TRANSPORT
Road
damages
Road
accidents
170,000 t MSW
Air emissions
0.69 t HC
8.58 t CO
1.46 t NOx
0.12 t TSP
946 t CO2
Figure 7.Error! Unknown switch argument. MSW Transport stage
7.1.1.2 Waste treatment
The treatment process starts with the lorries’ discharge in the reception section of the plant.
The waste passes to the selection conveyor belts where are manually separated the voluminous
110
Waste incineration cycle
residues and the recyclable materials (glass, paper and cardboard). The rest of the waste is
recirculated through a rotative screen where the organic matter is separated from the rest of
the waste. This organic matter is sent to the fermentation silos to make compost.
The voluminous residues are grinded and transported to the energy recovery pit to be
incinerated with the rest of residues.
The composting process is carried out inside channels of 50-70 m limited by 2 m walls topped
with rails. The organic residues are daily placed at the beginning of the channels. A tumbling
machine, supported on the top rails, stirs, grinds, homogenizes and moves the residues
towards the end of the channels. At the same time, the tumbled waste is aerated and
oxygenated. The organic matter, with optimal temperature and humidity conditions, suffers a
microbial aerobic decomposition that rises the waste temperature to 60-70ºC. The controlled
conditions of the process favours the obtention of compost of adequate characteristics.
From the inorganic fraction are separated manually other materials, as various types of plastics
and magnetic scrap.
The resulting refuse from the previous treatments, together with the voluminous residues
previously grinded, are conveyed to the energy recovery pit. It has a volume of 6,000 m3,
which can contain 3,000 tons of residues. 43% of the residues received in the plant go directly
into the pit.
Two bridge cranes take the residues from the pit to the feeding hoppers of the two
combustors. Once the residues are in the hopper, they fall by gravity into the boiler.
The combustion process takes place on travelling grates with steps that make the residues
move forward and mix them to achieve a complete combustion. The combustor has been
designed in such a way that the combustion gases remain at least two seconds over 840ºC, in
order to control the dioxins and furans emission that may have been formed in the combustion
process. There are also emergency gas burners that work if the combustion temperature falls
below 850ºC.
The combustion gases pass through a heat recovery steam generator (HRSG) with a steam
production capacity of 25.4 tons/hour of superheated steam at 61 bar and 380ºC. That steam
powers a steam turbine of 11.6 MWe. The alternator is connected to the electricity grid.
With the electricity generated in the plant, around 65,000 MWh, one third of the population of
the Mataró town could be supplied.
The steam from the turbine is condensed in an air cooled condenser, closing the steam cycle.
The flue gases from the HRSG pass through a limestone semi-humid scrubber. Limestone
slurry is sprayed over the flue gas stream and reacts mainly with the chloride and sulphur
contained in the gases. The new compounds formed precipitate and are separated in a cyclone.
The limestone consumption is around 12 kg per ton of MSW incinerated. At the same time, as
the gas temperature is reduced, the heavy metals evaporated in the incineration process at 850-
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ExternE National Implementation. Spain
1,000ºC, precipitate. The global removal efficiency for heavy metals particulates is around
99%, except that for mercury, that is about 95%.
The flying ashes and most of the particulates that have not been cleaned out in the scrubbing
process are retained in the electrostatic precipitators and stored in silos. The total volume of
this collected ashes is around 0.5% of the total MSW incinerated, and 3% in weight. Fly ash is
disposed in a landfill for inert materials, while bottom ash is transferred to a treatment plant
where it is prepared for use for road construction.
The stack height is 45 m, with a 2 m diameter.
Regarding to liquid effluents, the policy of the plant has been to minimize the water
consumption and disposal. That is the reason of having an air cooling system for the steam
cycle and using the process water very efficiently.
The water needs of the plant are supplied by the public water system, and it is around 0.5
m3/h. The water is used for general services of the plant buildings and in different processes:
steam cycle make up, gas neutralization and slag cooling. The purges from the steam cycle are
used to cover the needs of the other two processes. So there are no liquid effluents from the
plant apart from those from general services, that are disposed to the public sewage system.
The operation of the plant requires 52 people.
The construction period lasted for two years, during which the average number of workers
involved was 90. An estimation has been made of the construction materials, and their
transport needs, based on previous ExternE reports.
The waste treatment process is shown in the following figure.
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Waste incineration cycle
90 workers
(for two years)
9,000 t steel
25,000 t concrete
500 t cladding
and roofing
PLANT
CONSTRUCTION
Occupational accidents
Road damages
Air emissions
26 t SO2
2.6 t NOx
43 kg TSP
Air emissions
982 t CO2
52 workers
2,800 m3 water
1,754 t limestone
Compost
PLANT
OPERATION
170,000 t MSW
65,000 MWh
55,250 t CO2
6,163 kg TSP
20,075 kg SO2
84,137 kg NOx
21,118 kg CO
3,614 kg VOC
2,709 kg HCl
227 kg HF
370 kg Pb+Cr+Cu+Mn+Ni+As
7 kg Cd+Hg
1 g PCDD/F
Occupational accidents
33,000 t bottom ash
6,600 t fly ash
Recycled products
Road damages
Occupational accidents
5 workers
PLANT
DISMANTLING
9,000 t steel
25,000 t concrete
500 t cladding
and roofing
Air emissions
36 kg SO2
587 kg NOx
43 kg TSP
32 t CO2
Figure 7.Error! Unknown switch argument. Waste treatment process
7.1.1.3 Ash transport
Fly ash is disposed daily in an special landfill for inert materials. For its transport, one truck
per day is required.
110 t of bottom ash are produced daily, and transported by 4-5 trucks to a treatment plant
nearby, where they are prepared to be used as base materials for road construction.
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ExternE National Implementation. Spain
5 workers
60,000 km
33,000 t bottom ash
ASH TRANSPORT
6,600 t fly ash
Road
damages
Road
accidents
Air emissions
0.03 t HC
0.37 t CO
0.06 t NOx
0.01 t TSP
41.12 t CO2
Figure 7.Error! Unknown switch argument. Ash transport
7.1.2 Site description
7.1.2.1 Geographical location
The site of the municipal solid waste power plant is the municipality of Mataró, in the
province of Barcelona, in Northeastern Spain. The site is 4 km away from the nearest village,
Mataró, 26 km from Barcelona and 647 km northeast from Madrid, in a populated area, near
the Mediterranean coasts and mostly devoted to industry.
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Waste incineration cycle
CATALUÑA
Mataró
Barcelona
Madrid
Figure 7.Error! Unknown switch argument. Situation of the power plant within Barcelona and
Spain.
The geographical data of the site are the following:
Municipality:
Mataró
Province:
Barcelona
Region:
Cataluña
Latitude:
41º 31’20 N
Longitude:
2º 25’28 W
Altitude:
15 m
UTM coordinates:
x = 451,927
(time zone 31)
y = 4,597,393
In this study, the area within 50 km distance of the power plant site will be analyzed in order
to determine the local impacts that the plant may produce. The total area covered amounts to
10,000 km2. Error! Unknown switch argument. shows this area. The power plant site is
located in the center of the square.
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ExternE National Implementation. Spain
Girona
LLEIDA
Vic
GIRONA
BARCELONA
Manresa
Granollers
Terrassa
Igualada
Mataró
Power plant
Sabadell
Cerdanyola
Badalona
MAR
MEDITERRÁNEO
Barcelona
Villafranca
del Penedés
l’Hospitalet de Llobregat
TARRAGONA
El Vendrell
Sant Feliu
Vilanova i
La Geltrú
Figure 7.Error! Unknown switch argument. Area of study at local level.
7.1.2.2 Topography
Maresme district relief has two well defined units: the coastline mountain-chain and the
flatlands near the coast.
The Sierra de Marina belong to the central part of the Catalonian coastline mountain-chain.
The Montnegre-Corredor’s massif is one of the most important in this mountain-chain, with
the highest mountains in the Maresme district. Near this massif is located the municipal solid
waste power plant.
The coastal flatlands are very narrow, but in this area are located the main villages and crops.
They have an aqueous origin and they are greater where minor-watercourses corrade the lands.
The coastline is quite sandy, formed by deposit materials due to erosion. There are no relevant
rocky coasts, only in Arenys de Mar, Canet, Sant Pol and Calella beachs. However, groins are
very usual to protect the coast from unconsolidated materials of flatlands.
Error! Unknown switch argument. shows the topography of the reference environment of
the power plant.
116
Waste incineration cycle
Figure 7.Error! Unknown switch argument. Topography in the reference environment.
7.1.2.3 Hydrology
Surface hydrology in the studied area is built by short minor-watercourses from near
mountains. Their flows are very irregular and have a high sensitivity to rainfall.
Water flows through tranverse thrusts in the Corredor’s massif. An example of this is the
“riera de Argentona”. Montnegre’s watercourses have the most irregular flows. Sant Pol
minor watercourse collects water from several other minorwatercourses and it has water until
the summer in Sant Iscle de Vallalta.
7.1.2.4 Climatology
The area around the power plant is located in a district where climatology is defined by
geographical situation and relief units. So, climatology of the Maresme district is outlined by a
coastline mountain-chain, very close to the sea. This mountain-chain protects from northeast
cold winds in winter and condenses the water vapor. Moreover, climatology is softened by the
Mediterranean sea.
Rainfall is very irregular. Montnegre´s massif has the highest levels of rainfall in the district,
due to its height and the nearness to the Montseny’s massif, with heights over 1,700 m. This
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ExternE National Implementation. Spain
fact provides a great rainfall irregularity, with minimum values in summer and maximum
values in autumm and spring. Rainfall increases from SW to EN. So, while Mataró has 583
mm/year, Calella rises until 843 mm/year. Maximum level of rainfall occurs in autumn,
mainly in October.
Temperatures along the year are very constant, due to the smoothing effect of the sea and the
location of the coastline mountain-chain. Temperature variations increase in inland areas.
Annual average temperature in Mataró is 16.1ºC while in Conreria is 13.8ºC.
Maresme district has a characteristic coastal climatology, with annual rainfall between 600
and 800 mm. and quite soft temperatures. However, northern areas are colder and wetter.
Error! Unknown switch argument. summarizes in a monthly average basis the wind,
temperature and solar irradiation data of the meteorogical station located in the power plant.
Table 7.Error! Unknown switch argument. Climatology data in the reference site (1995).
January
February
March
April
May
June
July
August
September
October
November
December
Annual
Wind Velocity
(m/s)
1.53
1.38
1.42
1.25
1.20
1.08
1.15
1.18
1.10
0.81
1.11
1.25
1.21
Wind Direction
(degrees)
239.52
224.53
210.68
215.59
207.64
197.06
204.06
218.88
218.35
223.01
232.21
235.63
218.90
Temperature
(º c)
10.07
12.38
11.52
13.84
17.28
20.06
24.93
24.45
19.93
19.26
14.45
12.12
16.53
Solar irradiation
(w/m2)
79.50
120.83
187.98
216.83
254.59
236.32
271.56
227.29
173.93
128.82
88.87
58.66
169.56
7.1.2.5 Land use
General land distribution
The Maresme district has mainly Mediterranean natural vegetation. The most common species
that can be found are coastal holm oak, cork oak and mountainous holm oak in several points
of Montnegre. The coastline flatlands have northern grassland herbages.
White and stone pines (Pinus pinaster) are currently the most characteristic forests in
flatlands. Cork oak forests are located in highlands, near the Montnegre massif. Alder (Alnus
glutinosa) can be found near the watercourses.
The underbrush is built by Mediterranean shrubs like heather, furze (Ulex europaeus), pairies,
broom and rosemary.
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Waste incineration cycle
The human action has changed the vegetation in flatlands. So, crops are established over all
the inferior areas suppressing natural vegetation and beach communities. The only exception
is the sea rave.
The coast municipalities have the largest part of crop areas in the studied site, especially in the
Maresme district. For instance, the percentage of surface dedicated to crops is 53% in Arenys
de Mar, 30% in Mataró and 28% in Canet de Mar. On the other hand, forest surface is located
in inland and northern municipalities. So, Dosrius, Sant Iscle de Vallalta or Sant Cebrià de
Vallalta have more than 80% of their surface dedicated to forest.
Industrial location in the Maresme district is around Mataró, with more than 50% of the
industrial wage-earners. Other relevant industrial municipalities are Argentona and Canet.
Error! Unknown switch argument. summarizes the land distribution in the Maresme district
in 1,989.
Table 7.Error! Unknown switch argument. General land distribution in the Maresme district.
(ha.)
(%)
1,850
14.8
70
0.5
Forest
8,444
67.6
Other
2,126
17.0
Crop surfaces
Pastures
Agriculture
The most important crops in the reference area are forage, barley, wheat and green products.
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ExternE National Implementation. Spain
Green
products
9%
Wheat
12%
Oats
4%
Other
19%
Forage
30%
Barley
26%
Figure 7.Error! Unknown switch argument. Surface distribution by product.
Ecosystems
The Montnegre-Corredor Natural Park is located in the studied area. It was created in 1989
with an area of 15,000 ha. and two relevant units: the Corredor and the Montnegre. These
units are divided by the Vallgorguina and Arenys minor watercourses. The Santuario del
Corredor with 638 m. and the Turó de Ponent with 762 m. are the two highest points.
Holm oaks, cork oaks, white and stone pines are predominant in this Natural Park, but there
are other oaks, alders (Alnus glutinosa), chestnuts (Castanea sativa), birches and beeches
(Fagus silvatica) too.
The Montnegre-Corredor Natural Park has a great diversity of animal species like squirrels,
goshawks or white snakes and other reptiles, birds, insects and small mamals. This natural
park is an bird migration route too.
Relevant natural protected spaces in the reference area of the power plant are summarized in
Error! Unknown switch argument..
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Waste incineration cycle
Table 7.Error! Unknown switch argument. Ecosystems in the reference environment.
Name
1.Montnegre-Corredor
2.Riera d’Arbúcies-Hostalrich
3.Montseny
4.Montesquiu
5.Sant Llorenç del Munt i l’Obac
6.Muntanya de Montserrat
7.Garraf
8.Embassament del riu Foix
9.Delta del Llobregat
10.Collserola
11.Olérdola
Protection figure
Surface
(ha)
15,010
1989
Partial Natural
Reservoir
Natural Park
10 km.
1987
30,120
1977
Especial
Protection Plan
Natural Park
546
1985
9,638
1982
Natural Park
3,630
1987
Especial
Protection Plan
Especial
Protection Plan
10,638
1986
1,700
1993
Partial Natural
Reservoir
Especial
Protection Plan
Especial
Protection Plan
288
1987
7,992
1987
409
1992
Natural Park
Date
Latitude
Longitude
41º 38’ N
2º 33’ E
41º 46´ N
2º 35’ E
41º 46’ N
2º 23’ E
42º 07’ N
2º 13’ E
41º 39’ N
1º 55’ E
41º 36’ N
1º 48’ E
41º 17’ N
1º 53’ E
41º 15’ N
1º 38’ E
41º 17’ N
2º 04’ E
41º 27’ N
2º 00’ E
41º 18’ N
2º 43’ E
Observations
Mature forest systems.
River banks with
trees.
Holm and cork oaks,
birchs, pines and
chestnuts.
Oaks, ribera and albar
pines. Pastures.
Holm oaks and pines.
Relevant fauna.
Rocky formations.
Holm oaks.
Karstic area. Holm
oaks and pines.
Karstic area. Pinus
alepensis and dry
pastures.
Wet area formed by
coastline lakes.
Holm oaks, oaks and
pines.
Arqueologic center of
great value.
7.1.2.6 Population
The total population of the local area studied is 4,471,600 inhabitants, as taken from the
national census (National Institute of Statistics). Table 7.Error! Unknown switch argument.
shows their distribution according to age.
Table 7.Error! Unknown switch argument. Population distribution according to age (1986).
Age group
%
0-14
24.2
15-29
23.6
30-44
19.8
45-65
20.7
> 65
11.5
For the local area the population density is 447.1 inh/km2, what is very high, higher than the
population density for Spain (78 inh/km2).
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ExternE National Implementation. Spain
7.1.2.7 Transport network
The road network in the surrondings of the Mataró MSW power plant is formed by:
• the A-19 motorway from Barcelona to Mataró,
• the B-30 motorway from Mataró to Granollers,
• the Cabrera’s motorway to Malgrat, and
• the trunk road N-II from Barcelona to Girona.
All the villages in the reference area are linked by secondary roads. The most relevant are:
• the C-1415 from Mataró to Granollers, through Argentona and La Roca,
• the B-511 from Arenys de Mar to Sant Celoni,
• the BV-5101 from Dosrius to Canyamars,
• the BV-5031 from Mataró to Sant Vicenç de Montalt,
• the BV-5111 from Arenys de Mar to Sant Iscle de Vallalta, and
• the BV-5128 from Sant Iscle de Vallalta to Sant Pol del Mar.
The railway from Barcelona to Blanes goes over the Maresme district.
In Error! Unknown switch argument., the transport network of the area is shown.
122
Waste incineration cycle
Girona
N-141
A-17
Vic
N-II
C-253
C-250
San Felíu
de Guixois
N-141
N-152
A-17
Manresa
Blanes
Arenys de M ar
N-II
Granollers
B-30
Terrasa
Sabadell
Igualada
N-II
A-17
M ataró
A-19
Ripollet
Martorell
Cerdanyola
El M asnou
M ontgat
Badalona
A-7
BARCELONA
N-340
Sant Feliu
l’Hospitalet de Llobregat
Figure 7.Error! Unknown switch argument. Transport network in the reference environment.
7.2 Overview of burdens
The most important burdens of the waste incineration cycle are the atmospheric emissions
generated by the power generation stage. Of important concern within these emissions are the
dioxins and furans ones, whose effect on human health is still in dispute.
The amount of km traveled (1,440,000 per year) is also an important burden of this cycle, due
to the impact on roads, and on road accidents.
Liquid effluents have not been determined, although they are not expected to be significant.
As for solid waste generation, only ash production is significant, with some 40,000 t produced
yearly.
7.2.1 Atmospheric emissions
Table 7.Error! Unknown switch argument. Atmospheric emissions of the waste incineration
cycle (g/MWh)
1. MSW transport
2. Waste treatment
3. Ash transport
TOTAL
PM10
1.8
95
0.2
97
SO2
nd
309
nd
309
NOx
23
1294
0.9
1318
CO2
14,554
850,000
633
865,000
CO
132
325
6
463
HC
10.6
nd
0.5
11
VOC
nd
57
nd
57
HCl
nd
42
nd
42
PCDD/F
nd
1.5e-5
nd
1.5e-5
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ExternE National Implementation. Spain
nd : not determined
7.3 Selection of priority impacts
The main impacts that are expected to be produced because of the MSW fuel cycle are those
produced by the atmosferic emissions of the generation stage. Of special concern are effects
on public health caused by dioxins and furans. Error! Unknown switch argument. displays
the impacts of each stage of the MSW fuel cycle.
Table 7.Error! Unknown switch argument. Impacts of the MSW fuel cycle.
Impact
Transport Generation Waste disposal Construction
Public health
x
x
x
Occupational health
x
x
x
Global warming
x
x
x
Crops
x
x
x
Forests
x
x
x
Materials
x
x
x
Ecosystems
x
x
x
x
Visual impact
x
x
Noise
x
x
Odour
x
Road traffic
x
The effects of ozone, because of NOx and VOCs emissions, the high insolation of the area,
and its urban characteristics are also expected to be significant. However, no ozone dispersion
model is available now.The effects of acid pollutants on forests and materials will be also
assessed. The effect on crops is not expected to be too large, because of the low SO2
emissions.
A specific impact of this cycle is that caused by road traffic, which is very heavy due to the
low density of the fuel.
The global warming effects of CO2 will also be considered, as well as the workers and public
accidents along the cycle. Other impacts such as noise or visual impact will not be assessed
due to their local nature.
So, the priority impacts that will be assessed are:
•
•
•
•
•
•
•
Public health,
Occupational health,
Forests,
Ecosystems,
Materials,
Road traffic, and
Global warming.
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Waste incineration cycle
7.4 Quantification of impacts and damages
7.4.1 MSW transport
The major impact of this stage is the road damage caused by the vehicles used for MSW
transport. This is justified on the basis of the low energy density of the MSW fuel. However,
this impact may be internalized through road taxes in some countries.
The impact of atmospheric emissions from transport has not been considered, since the
emissions from this stage contribute very little to the total emissions of the whole process.
Table 7.Error! Unknown switch argument. Impacts and damages of MSW transport
Impact
Road accidents
Deaths
Major injuries
Minor injuries
Road damages
Global warming
na: not applicable
Burden
Impacts
Damages
Unit
per TWh mECU/kWh
ECU/t poll.
0.17
0.48
0.88
km
traveled
CO2
repair
costs
σg
0.44
6.0e-2
1.7e-3
1.0
na
na
na
na
A
A
A
A
5.5e-2 - 2.0
3.8 - 139
C
7.4.2 Waste treatment
CO2 and NOx emissions from the power plant cause the largest damages for this stage. The
effects on human health, and on materials, of other atmospheric emissions is also significant.
Damages on human health are specially large for this case because of its proximity to a very
large population centre, Barcelona, what makes TSP damages rise considerably compared to
other fuel cycles. One important aspect of this plant is that the local health impacts account for
some 85% of the total impacts of the power plant, due to the very high population density of
the area.
Damages on crops, which might be important for this plant because of the concentration of
high value agricultural activity around the area, is certainly underestimated, since only
damages for cereals have been assessed.
The impacts caused by dioxins and furans, in spite of the social concern involved, are from
our estimations four orders of magnitude smaller than for TSP.
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Table 7.Error! Unknown switch argument. Impacts and damages of power generation
Impact
Human health
Chronic YOLL
Acute YOLL
Morbidity
Crops
Ecosystems
Materials
Occupational accidents
Deaths
Major injuries
Minor injuries
Road damages
Global warming
na: not applicable
Burden
TSP
Nitrates
Sulfates
SO2
Ozone
Nitrates
Ozone
CO
PCDD
SO2
Sulfates
TSP
SO2
Ozone
N dep.
Impacts
Unit
per TWh
years
years
years
years
2.00e+1
1.38e+2
2.66e+1
7.57e-1
cases
8.53e+3
cases
add. cancer
cases
cases
cases
dt yield loss
2.02e+1
1.76e-4
2.89e-1
1.64e+3
1.23e+3
5.60e+2
kg fertilizer
added
Ac. dep.
kg lime
added
N dep.
km2 exceed.
area
SO2
km2 exceed.
area
NOx
km2 exceed.
area
SO2
m2 maint.
area
km
traveled
CO2
repair costs
mECU/kWh
Damages
ECU/t poll.
σg
1.69
11.7
2.24
1.17e-1
7.65e-1
1.50
1.36
1.59e-1
17800
9000
7250
380
676
1160
1202
489
B
B?
B
B
B
A-B?
B
B
-8.17e+4
2.28e-3
2.79e-1
2.16e-1
4.13e-3
6.25e-1
-1.40e-3
7.36
903
2280
13.4
546
na
A-B
A-B
A-B
A
B
A
4.00e+5
6.86e-3
na
A
0
0
0
0
0
0
6.61e+3
9.83e-2
318
B
0.2
1.1
40.6
0.5
1.4e-1
7.8e-2
1.2e-2
na
na
na
na
A
A
A
A
3.2 - 118.2
3.8 - 139
C
7.4.3 Ash transport
As for other transport stages, the major impact assessed has been road damages, which may
already be internalized. It has to be said that the impacts of this stage are very small compared
to those of the other stages.
126
Waste incineration cycle
Table 7.Error! Unknown switch argument. Impacts and damages of fuel transport
Impact
Burden
Road accidents
Deaths
Major injuries
Minor injuries
Road damages
Global warming
na: not applicable
Impacts
Damages
Unit
per TWh mECU/kWh
ECU/t poll.
7.7e-3
2.2e-2
3.8e-2
km
traveled
CO2
repair
costs
σg
2.0e-2
2.7e-3
7.3e-5
4.3e-2
na
na
na
na
A
A
A
A
2e-3 - 8.8e-2
3.8 - 139
C
7.4.4 Impacts and damages related to waste treatment
Table 7.Error! Unknown switch argument. Impacts and damages of power generation
Impact
1. MSW transport
Road accidents
Deaths
Major injuries
Minor injuries
Road damages
Global warming
2. Waste treatment
Human health
Chronic mortality
Acute mortality
Morbidity
Crops
Materials
Occupational accidents
Deaths
Major injuries
Minor injuries
Road damages
Global warming
3. Ash transport
Road accidents
Deaths
Major injuries
Minor injuries
Road damages
Global warming
Damage in ECU per t of waste
1.7e-1
2.3e-2
6.5e-4
3.8e-1
2.1e-2 - 7.7e-1
6.0
4.5e-2
8.2e-1
1.6e-3
3.8e-2
1.9e-1
5.4e-2
3.0e-2
4.6e-3
1.2 – 45.2
7.6e-3
1.0e-3
2.8e-5
1.6e-2
7.4e-4 - 3.3e-2
127
ExternE National Implementation. Spain
7.5 Summary and interpretation of results
Table 7.Error! Unknown switch argument. Damages of the waste incineration cycle
mECU/kWh
σg
POWER GENERATION
Public health
Mortality*- YOLL (VSL)
16.3 (60.9)
B
of which TSP
1.7 (6.2)
SO2
2.4 (11.4)
NOx
11.7 (42.8)
NOx (via ozone)
0.53
NMVOC (via ozone)
0.23
Morbidity
3.2
of which TSP, SO2, NOx, CO
2.2
A
NOx (via ozone)
0.95
B
NMVOC (via ozone)
0.41
B
PCDD/F
ng
B
Accidents
ng
A
Occupational health
0.72
A
Major accidents
nq
Crops
0.45
B
of which SO2
4.1e-3
NOx (via ozone)
0.45
NMVOC (via ozone)
0.17
B
Ecosystems
ng
B
Materials
9.8e-2
B
Noise
nq
Visual impacts
nq
Global warming
C
low
3.2
mid 3%
15.3
mid 1%
39.1
upper
118.2
OTHER FUEL CYCLE STAGES
Public health
0.52
A
Occupational health
nq
A
Ecological effects
nq
B
Road damages
1.0
A
Global warming
C
low
5.8e-2
mid 3%
2.7e1
mid 1%
7.0e-1
upper
2.1
*Yoll= mortality impacts based on ‘years of life lost’ approach, VSL= impacts evaluated based on ‘value of
statistical life’ approach.
ng: negligible; nq: not quantified; iq: only impact quantified; - : not relevant
128
Waste incineration cycle
Table 7.Error! Unknown switch argument. Sub-total damages of the waste incineration cycle
YOLL (VSL)
low
mid 3%
mid 1%
upper
mECU/kWh
25.6 (70.2)
37.9 (82.5)
62.1 (106.7)
142.6 (187.2)
Table 7.Error! Unknown switch argument. Damages by pollutant
SO2 *- YOLL (VSL)
NOx *- YOLL (VSL)
PM10 *- YOLL (VSL)
NOx (via ozone)
VOC (via ozone)
CO2
ECU / t of pollutant
9001 (38142)
10198 (34224)
20250 (67711)
1500
930
3.8 - 139
*Yoll= mortality impacts based on ‘years of life lost’ approach, VSL= impacts evaluated based on ‘value of
statistical life’ approach.
The damages of this fuel cycle are rather large (even excluding global warming), mostly due
to the site in which it is located, very near to a large population centre. This explains the large
damages per t of pollutant emitted. However, it is not really sensible to consider the change of
the location, since MSW plants are usually installed near, or inside, large cities.
Therefore, since the damages per t of pollutant will be high for most cases, the only way of
reducing the damages caused by atmospheric emissions of waste incineration is to reduce
emission factors, by improving the environmental performance of the technology.
Technology is also responsible for the high damages caused by global warming. If better
conversion technologies were used, with higher efficiencies, global warming damages might
be reduced. It has to be noted that here MSW have not been considered as renewable, that is,
carbon neutral, what is sometimes the case.
An important remark to be made is that the effect of dioxins is quite small, contrary to what
might be expected according to public concern.
These would be the conclusions of the assessment of waste incineration as an energy source.
However, that should not be the only point of view. Since MSW should be disposed of
anyway, a comparison with the damages caused by alternative disposal schemes should be
carried out, so that the net effects might be ascertained.
129
ExternE National Implementation. Spain
130
8. AGGREGATION
8.1 Description of the national electricity sector
As shown in section 1.4.2, Spanish electricity comes mainly from three sources: nuclear,
hydro, and fossil fuels. Of fossil fuels, the greatest share goes for national coal.
The current Spanish electricity mix is conditioned by the non-liberalized nature of the
electricity sector. Several restrictions apply, such as the compulsory use of national fuels (27.7
kt of coal and lignites for 1996), environmental regulations, etc.
There is a large controversy nowadays about the role that national coal and lignites, specially
the latter, will play in the generation mix. Except for some cases, domestic fuels are much
more expensive, and much more polluting, than imported coal or gas. However, coal mining
provides a very important income source for some areas, and so, its elimination would
produce serious social effects. Therefore, it seems that national fuels will still be used at least
in the short term. This situation might change in the next years, if the free energy market
becomes operative.
The large presence of hydro produces also a large variability of the generation mix, depending
on climatology. The nuclear share is almost constant, as it is used for base load. The rest
changes according to climatology, and to the national coal quotas set by the Government.
For 1996, the electricity generation mix for the main grid (i.e., excluding independent power
producers and cogeneration) is shown in the following table.
Table 8.Error! Unknown switch argument. Spanish electricity generation mix for 1996
Energy source
Electricity generated
Electricity share
(GWh)
(%)
Nuclear
53,693
33.3
Hydro
41,619
25.8
Coal (national)
35,914
22.2
Coal (imported)
10,328
6.4
Brown lignite
9,459
5.9
Black lignite
9,493
5.9
Gas
732
0.5
Fuel
194
0.1
131
ExternE National Implementation. Spain
8.2 Aggregation methods
Two major problems exist for a reasonable aggregation of the external costs of the Spanish
electricity sector. The first one is the large amount of electricity generated by nuclear and
hydro. The second one is the unavailability of a multi-source EcoSense version for estimating
the impacts of atmospheric pollution. Both introduce a large degree of uncertainty in the
analysis.
Nuclear and hydro fuel cycles have not been deeply studied yet, specially nuclear. Several
issues remain to be cleared for this fuel cycle, some of which are expected within the Core
Project. However, the implementation of these latest improvements to the existing results, for
their use in aggregation, is not available yet.
For hydro, the major problem is that most of its impacts are those on local environment and
population, and that makes the transferability of results really difficult.
As far as the nuclear impact is concerned, the nuclear cycle is different, plant characteristics
are not the same, and the sites cannot be compared with the references already estimated. Risk
aversion might also be characteristic of the Spanish situation.
Therefore, the reliability of the damage transfer to Spanish conditions is not expected to be
high. This is further aggravated by the already mentioned fact that most of Spanish electricity
comes from these sources. However, since some values are needed to carry out the
aggregation, those figures obtained in previous implementations of these fuel cycles will be
used.
The second problem is the unavailability of a multi-source version of EcoSense software for
Spain. This has forced us to use a simpler aggregation method for the damages of atmospheric
pollution.
The simple method proposed by the Core Project recommended to extrapolate damages per t
of pollutant emitted by any plant in the country. However, the research undertaken has
demonstrated that the location is really significant for the quantification of the damages. In
fact, for three different Spanish plants sited less than 150 km apart from each other, we have
obtained damages per t of pollutant emitted which vary around 20%. This may be due, among
other reasons, to the background pollutant emissions, which affect results to a significant
extent.
Therefore, more than one power plant has been analyzed. The assessment has been carried out
with EcoSense software. The problem here resides in that the atmospheric dispersion models
included in EcoSense are not well suited to the complex Spanish topography, and therefore
the accuracy of the results is not expected to be too high.
The not consideration of complex topography by EcoSense has determined the selection of the
representative locations. This selection has been done based only on a geographical basis,
without taking into account the site characteristics, which, in some cases, might prove to be
really significant, or the local meteorological conditions. Hence, one real plant has been
132
Aggregation
selected for each region in which power plants exist, so that their results might be then
extrapolated to the rest of power plants in that area. The power plants selected have been:
Puentes de García Rodríguez, Teruel, Aboño, Compostilla, Pasajes, Puertollano, Litoral de
Almería, Los Barrios, Colón, and Foix. Since results have been obtained per t of pollutant
emitted, they are only dependent on the location of the power plant. Fuel type and technology
are introduced in the analysis by the pollutant emission factor, which depends on these two
factors.
Technological data introduced in EcoSense have been obtained from the Ministry of Industry,
and from the fuel consumption and composition provided by electric utilities.
These emission factors have been calculated based on the fuel composition, according to
estequiometric relationships. Results have then been checked with real emission factors for
some of the plants, for which some information was available.
By linking the damages per t of pollutant emitted with the emission factors, the damage per
kWh generated has been calculated. This damage has then been multiplied by the electricity
generation of each power plant in 1996, to obtain the total damages produced for this year.
It has to be noted that only the generation stage of the fossil fuel cycles has been assessed.
Although the ExternE methodology recommends to address all stages, this would have
complicated too much the assessment, without providing substantial changes in the results,
due to the very high percentage of total fuel cycle damages caused by the generation stage.
However, for some fuel cycles, this simplification may introduce some uncertainties.
Only health damages have been included in the analysis. This has been done in order to make
it simpler, once considering that, for all cases assessed, health damages make up for more than
99% of the total damages estimated, excluding global warming. These health damages have
been estimated based on the YOLL approach, since it is the one preferred by the methodology.
Only damages caused by TSP, SO2 and NOx have been considered, since ozone damages are
much smaller.
Regarding global warming, its assessment has been carried out separately, due to the
uncertainty lied to it. Damages have been quantified for the whole Spanish electricity sector,
based on the total CO2 emissions.
The results obtained using these aggregation methods are shown in the next section.
8.3 Results
As has been mentioned, the results presented here should only be regarded as approximate,
indicative figures. Besides from the uncertainty lied to the externality assessment process,
several uncertainty sources have been introduced in the aggregation procedure, such as the
extrapolation of results from one location to another, the determination of emission factors, or
the direct extrapolation of nuclear and hydro externalities.
133
ExternE National Implementation. Spain
Anyway, it is expected that these results may provide a useful indication of the external costs
of the electricity generation system in Spain, so that they may be used for a better
environmental management of this system.
In the following table, the damages in ECU per t of pollutant emitted are shown for each of
the Spanish fossil power plants, along with the emission factors for TSP, NOx, and SO2.
Table 8.Error! Unknown switch argument. Damages and emission factors of fossil power
plants in Spain
Power group
National coal
Aboño1
Aboño2
Lada3
Lada4
Soto1
Soto2
Soto3
Narcea1
Narcea2
Narcea3
Anllares
Compostilla1
Compostilla2
Compostilla3
Compostilla4
Compostilla5
La Robla1
La Robla2
Guardo1
Guardo2
Puertollano
Puentenuevo
Imported coal
Pasajes
Litoral
Los Barrios
Black lignites
Serchs
Escatrón
Teruel1
Teruel2
Teruel3
Escucha
Brown lignites
Puentes1
Puentes2
Puentes3
Puentes4
Meirama
Fuel
San Adrián2
Algeciras1
Algeciras2
Escombreras1
Escombreras2
Escombreras3
Escombreras4
134
Emission factors (g/kWh)
SO2
NOx
TSP
SO2
Damages (ECU/t)
NOx
TSP
6.2
6.3
7.7
7.2
6.4
7.7
7
7.2
7.5
7.3
7.8
7.7
7.8
7.8
7.8
7.8
7.7
7.8
7.2
7.2
7.7
7.8
3.7
3.6
4
3.8
3.1
4
3.7
3.5
3.8
3.7
4
3.9
4
4
4
4
3.9
3.9
3.8
3.8
3.9
4
0.4
0.4
0.6
0.5
0.5
0.6
0.5
0.5
0.5
0.5
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.5
0.5
0.6
0.6
6991
6991
6991
6991
6991
6991
6991
6991
6991
6991
5813
5813
5813
5813
5813
5813
5813
5813
5813
5813
6361
6361
8170
8170
8170
8170
8170
8170
8170
8170
8170
8170
6554
6554
6554
6554
6554
6554
6554
6554
6554
6554
7556
7556
6121
6121
6121
6121
6121
6121
6121
6121
6121
6121
4876
4876
4876
4876
4876
4876
4876
4876
4876
4876
6483
6483
3.5
3.5
3.5
2.5
2.5
2.5
0.1
0.1
0.1
9583
5657
4219
12076
6136
4651
10780
5083
4418
18.1
3.8
22.1
22.2
22.2
27.5
2.7
3.2
2.8
2.8
2.9
3
0.3
0.5
0.3
0.3
0.3
0.3
7450
7450
7450
7450
7450
7450
4823
4823
4823
4823
4823
4823
6847
6847
6847
6847
6847
6847
17.3
18
17.3
17.3
23.3
3.1
2.9
3.2
3.1
2.6
0.5
0.5
0.5
0.5
0.5
5073
5073
5073
5073
5073
2918
2918
2918
2918
2918
5262
5262
5262
5262
5262
5.1
5.1
5.1
5.1
5.1
5.1
5.1
1.6
1.6
1.6
1.6
1.6
1.6
1.6
0.2
0.2
0.2
0.2
0.2
0.2
0.2
8427
4219
4219
5657
5657
5657
5657
8983
4651
4651
6136
6136
6136
6136
8107
4418
4418
5083
5083
5083
5083
Aggregation
Power group
Escombreras5
Aceca1
Aceca2
Sabón1
Sabón2
Castellón1
Castellón2
Badalona1
Badalona2
Colón1
Colón2
Colón3
Gas
Besós1
Besós2
Foix
San Adrián 1
San Adrián 3
Elcogas
Emission factors (g/kWh)
SO2
NOx
TSP
5.1
1.6
0.2
5.1
1.6
0.2
5.1
1.6
0.2
5.1
1.6
0.2
5.1
1.6
0.2
5.1
1.6
0.2
5.1
1.6
0.2
5.1
1.6
0.2
5.1
1.6
0.2
5.1
1.6
0.2
5.1
1.6
0.2
5.1
1.6
0.2
0
0
0
0
0
0
1.6
1.6
1.6
1.6
1.6
0.4
0
0
0
0
0
0
SO2
5657
6361
6361
5073
5073
8427
8427
8427
8427
4820
4820
4820
Damages (ECU/t)
NOx
6136
7556
7556
2918
2918
8983
8983
8983
8983
5753
5753
5753
TSP
5083
6483
6483
5262
5262
8107
8107
8107
8107
5426
5426
5426
8427
8427
8427
8427
8427
6361
8983
8983
8983
8983
8983
7556
8107
8107
8107
8107
8107
6483
These values allow us to calculate the externality of electricity generation by each power plant
in mECU/kWh.
By multiplying these values by the electricity generated in 1996, we may estimate the damages
caused by the generation stage of fossil fuels on human health, which, as said before, make up
for most of the total damage caused by these fuel cycles.
As mentioned before, the values for nuclear and hydro fuel cycles have been extrapolated
directly from European values (the one for nuclear corresponding to a 0% discount rate, which
may be more reasonable due to the long-term nature of the impacts), and so the results for
these electricity sources should be regarded with caution.
All these figures are shown in Error! Unknown switch argument..
135
ExternE National Implementation. Spain
Table 8.Error! Unknown switch argument. Externalities of the Spanish electricity system
Power group
Damages in mECU/kWh
SO2
NOx
TSP TOTAL
Aboño1
43.34
30.23
2.45
76.02
Aboño2
44.04
29.41
2.45
75.90
Lada3
53.83
32.68
3.67
90.18
Lada4
50.33
31.05
3.06
84.44
Soto1
44.74
25.33
3.06
73.13
Soto2
53.83
32.68
3.67
90.18
Soto3
48.93
30.23
3.06
82.23
Narcea1
50.33
28.60
3.06
81.99
Narcea2
52.43
31.05
3.06
86.54
Narcea3
51.03
30.23
3.06
84.32
Anllares
45.35
26.22
2.93
74.49
Compostilla1
44.76
25.56
2.93
73.25
Compostilla2
45.35
26.22
2.93
74.49
Compostilla3
45.35
26.22
2.93
74.49
Compostilla4
45.35
26.22
2.93
74.49
Compostilla5
45.35
26.22
2.93
74.49
La Robla1
44.76
25.56
2.93
73.25
La Robla2
45.35
25.56
2.93
73.83
Guardo1
41.86
24.91
2.44
69.20
Guardo2
41.86
24.91
2.44
69.20
Puertollano
48.98
29.47
3.89
82.34
Puentenuevo
49.61
30.23
3.89
83.73
NATIONAL COAL
78.20
Pasajes
33.54
30.19
1.08
64.81
Litoral
19.80
15.34
0.51
35.65
Los Barrios
14.76
11.63
0.44
26.84
IMPORTED COAL
36.30
Serchs
134.84
13.02
2.05
149.92
Escatrón
28.31
15.43
3.42
47.16
Teruel1
164.64
13.50
2.05
180.20
Teruel2
165.38
13.50
2.05
180.94
Teruel3
165.38
13.99
2.05
181.42
Escucha
204.87
14.47
2.05
221.39
BLACK LIGNITES
175.35
Puentes1
87.77
9.04
2.63
99.44
Puentes2
91.32
8.46
2.63
102.41
Puentes3
87.77
9.34
2.63
99.74
Puentes4
87.77
9.04
2.63
99.44
Meirama
118.21
7.59
2.63
128.42
BROWN LIGNITES
106.75
San Adrián2
42.98
14.37
1.62
58.97
Algeciras1
21.51
7.44
0.88
29.84
Algeciras2
21.51
7.44
0.88
29.84
Escombreras1
28.85
9.82
1.02
39.68
Escombreras2
28.85
9.82
1.02
39.68
Escombreras3
28.85
9.82
1.02
39.68
Escombreras4
28.85
9.82
1.02
39.68
Escombreras5
28.85
9.82
1.02
39.68
Aceca1
32.44
12.09
1.30
45.83
Aceca2
32.44
12.09
1.30
45.83
Sabón1
25.87
4.67
1.05
31.59
Sabón2
25.87
4.67
1.05
31.59
Castellón1
42.98
14.37
1.62
58.97
Castellón2
42.98
14.37
1.62
58.97
Badalona1
42.98
14.37
1.62
58.97
Badalona2
42.98
14.37
1.62
58.97
Colón1
24.58
9.20
1.09
34.87
Colón2
24.58
9.20
1.09
34.87
Colón3
24.58
9.20
1.09
34.87
136
GWh/yr
electricity
2788
3804
757
2401
0
1902
2327
0
384
2265
2586
1008
105
2213
2588
2588
1296
1947
0
1843
1187
1925
35914
1570
4328
4430
10328
476
492
2601
2594
2594
702
9459
2077
1081
1978
2095
2262
9493
0
39
0
0
0
0
0
0
88
0
0
0
0
0
0
0
0
67
0
Damages in kECU per year
Mid
%
211945
3.5%
288733
4.7%
68268
1.1%
202741
3.3%
0
0.0%
171526
2.8%
191338
3.1%
0
0.0%
33230
0.5%
190990
3.1%
192622
3.1%
73836
1.2%
7821
0.1%
164838
2.7%
192771
3.1%
192771
3.1%
94931
1.6%
143749
2.3%
0
0.0%
127535
2.1%
97735
1.6%
161180
2.6%
2808558
45.9%
101753
1.7%
154285
2.5%
118881
1.9%
374919
6.1%
71360
1.2%
23205
0.4%
468692
7.7%
469363
7.7%
470614
7.7%
155416
2.5%
1658649
27.1%
206545
3.4%
110707
1.8%
197277
3.2%
208335
3.4%
290497
4.7%
1013361
16.5%
0
0.0%
1164
0.0%
0
0.0%
0
0.0%
0
0.0%
0
0.0%
0
0.0%
0
0.0%
4033
0.1%
0
0.0%
0
0.0%
0
0.0%
0
0.0%
0
0.0%
0
0.0%
0
0.0%
0
0.0%
2336
0.0%
0
0.0%
Aggregation
Power group
Damages in mECU/kWh
NOx
TSP TOTAL
FUEL
38.83
Besós1
0.00
14.37
0.00
14.37
Besós2
0.00
14.37
0.00
14.37
Foix
0.00
14.37
0.00
14.37
San Adrián 1
0.00
14.37
0.00
14.37
San Adrián 3
0.00
14.37
0.00
14.37
Elcogas
0.00
3.02
0.00
3.02
GAS
10.22
Asco1
2
Asco2
2
Almaraz1
2
Almaraz2
2
Cofrentes
8
Vandellós
2
Garoña
8
Trillo
2
J.Cabrera
2
NUCLEAR
3.18
TOTAL HYDRO
2
37.94
TOTAL ELECTRICITY SYSTEM
SO2
GWh/yr
electricity
194
0
123
180
161
0
268
732
7577
5667
5671
7581
7402
7507
3121
7971
1196
53693
41619
161432
Damages in kECU per year
Mid
%
7533
0.1%
0
0.0%
1768
0.0%
2587
0.0%
2314
0.0%
0
0.0%
810
0.0%
7479
0.1%
15154
0.2%
11334
0.2%
11342
0.2%
15162
0.2%
59216
1.0%
15014
0.2%
24968
0.4%
15942
0.3%
2392
0.0%
170524
2.8%
83238
1.4%
6,124,261
100.0%
The final result is affected, as all the results calculated within this report, by an uncertainty
factor. For the damages considered here, that is, health damages, the corresponding
uncertainty factor is a B, that is, a σg ranging from 4 to 6. Given that most of the damage is
caused by chronic mortality, for which the σg is 4, we will use this value to illustrate the
confidence intervals which might be expected for these results.
Confidence interval of 68% : 1,531,065 to 24,497,044 kECU
Confidence interval of 95% : 382,766 to 97,988,176 kECU
As may be seen, the average total figure obtained is rather large, up to more than 106 million
Ptas, that is, more than 1% of the Spanish GDP in 1994, or around 47% of the electricity
sector turnover in 1996.
It has to be reminded that these results do not include global warming damages, which are
presented in the following table, aggregated for the whole electricity sector.
Table 8.Error! Unknown switch argument. Global warming damages
CO2 emissions in kt
Damage in ECU per t
70,345
3.8
18
46
139
Total damages in 1996
(kECU per year)
267,311
1,266,210
3,235,870
9,777,955
These figures range from 4.36% to 160% of the mid-estimates for TSP, SO2, and NOx
damages. This broad range shows the difficulty of dealing with CO2 effects for the policy case
study presented in the next chapter.
137
9. POLICY CASE STUDY
9.1 Introduction
The objective of this case study is to include the results obtained from the ExternE Project in a
particular aspect of the decision making process. Therefore, the externalities of the energy
generation obtained within this project could be used in an economic task such as operation
and planning of the electric power systems of an UE country.
For the Spanish case, it is being developed a production cost model to simulate and optimise
the operation of the system under medium term analysis. The integration of the external costs
among the different generation technologies in the model, and to evaluate the system
performance under social costs minimisation criterion, are the main objectives of this policy
case study.
The main tasks of this policy case are the following.
• ExternE methodology to be used and calculation of externalities.
The ExternE Project will be used as the main source of information for the calculation
of externalities. The fuel cycle will be analysed and external costs will be estimated for
representative plants of the Spanish electricity network. The results will be estimated
for representative plants of the Spanish electricity system.
• Model for the exploitation of the electricity network: development of the model,
and adaptation of the model for the introduction of externalities.
A computer model will be described and developed to provide the minimum variable
cost for the exploitation of the Spanish electricity network, subject to operating
constraints such as generation, transmission and national fuel consumption limits. The
model will be adapted to enable the introduction of externalities into the final decision
process.
• Evaluation and analysis of different cases.
Different case studies will be defined varying parameters of the model such as demand
scenarios, hydraulic years, consumption of national fuels, etc. The selected cases will
be run and the obtained results will be analysed.
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ExternE National Implementation. Spain
9.2 Policy case study description
The electricity network model is being developed by the Institute for Research in Technology
(IIT) of the "Universidad Pontificia Comillas" of Madrid. The model will be of the operational
type and not a planning tool. The aim of the program will be to provide the minimum variable
cost for the exploitation of the Spanish electricity network, subject to operating constraints
such as generation and fuel consumption limits. It is being designed to represent yearly
operation of the Spanish electric power system, and it would be used for medium term
economic planning.
The Spanish electricity system is composed of hydroelectric, nuclear and thermal units. These
last units are mainly coal plants, which consume national and imported coal. National coal has
compulsory consumption quota set by the Government, which is one of the constraints of the
system. Each one of these areas of electricity production has a different contribution to the
domestic production. Their share may vary depending on the hydro inflows per year, fuel
imports policy or other yearly constraints.
All the electricity production units of the country that exceed a certain capacity are included in
the program. At the moment, only the internal costs of the system are taken into account to
perform the economic central dispatch of the overall generation units of the Spanish electric
power. The integration of external costs in the model may vary in a significant way the
decision process.
The external cost associated to each plant can be introduced as another defining parameter for
the system. The ExternE Project provides site and technology specific studies, so each unit
would have its associated external cost expressed in terms of mECU/kWh.
As is will not be possible to carry out an study for each electricity generation unit in the
country, a representative case for each kind of plant will be analysed. For the rest of the units,
some extrapolation will be necessary. To perform this task, results from the aggregation part
of the ExternE Project will be deemed necessary, as explained in section 8.
The results from this case study will give a first approximation of the influence of external
costs in the medium term economic planning of the electricity power system of an EU
country.
9.3 Model description
Power plants have been traditionally dispatched by minimum fuel cost criteria, in what has
been called economic dispatch optimal load flow. This process did not consider the
contamination produced in the energy generation, mainly in the generated with fossil fuels.
The tool described in this document permits the evaluation of the contamination reduction
mechanisms in large electric systems (more than 100 generators). It is a model of annual
operation that reproduces the system considering in detail the generation activities. It also
considers the cogeneration as well as the energy interchanges with other systems. It models
140
Policy case study
precisely the most relevant pollutants and apply the external costs that their contamination
implies. Some of its results are the gross and net monthly productions, fuel consumption,
different pollutant emissions and variable and external costs of operation. All these can be
obtained in different optimisation conditions as minimum emissions, minimum social costs,
minimum operation costs under certain pollutants constraints, etc.
This model provides the minimum variable cost (or social) subject to operating constraints
(generation, fuel and emissions constraints). Generation constraints include power reserve
margin with respect to the system peak load, balance between generation and demand, hydro
energy scheduling, maintenance scheduling, and generation limitations. Fuel constraints
include minimum consumption quotas and fuel scheduling for domestic coal thermal plants.
Emissions constraints apply to fossil fuel units. The relevant decision variables and the real
operation of the power system are adequately represented, two types of decisions are
addressed:
• Interperiod decisions are those regarding resources planning for multiple periods. In
particular, maintenance scheduling for thermal units, yearly hydro energy scheduling,
seasonal operation of pumped-hydro units (A pumped-hydro unit is a pump-turbine having
a large upper reservoir with seasonal storage capability that receives water from pumping
and also from natural hydro inflows. By the contrary, a pumped-storage unit has a small
upper reservoir filled only from pumped water allowing just a weekly or dairy cycle), and
fuel scheduling are represented. The model determines the optimal hydrothermal coordination (i.e., the use of hydro against thermal generation resources).
• Intraperiod decisions correspond to a generation economic dispatch. In particular, those
related to weekly/daily operation of pumped-storage units and commitment decisions of
thermal units.
This operations planning problem is formulated as a large-scale mixed integer optimisation
problem. The model has been implemented in GAMS, a mathematical specification language
specially indicated for the solution of optimisation problems, and solved by using CPLEX, a
well-known MIP solver.
The medium term planning problem is stochastic by nature. Uncertainties arise in load, hydro
inflows, thermal unit availability, etc. However, the model described is deterministic.
Stochasticity in unit availability and load can be naturally implemented within this
methodology via scenarios. Uncertainty in hydro inflows is modelled deterministically
because medium term operation planning is performed under the assumption of average
hydrology.
No model with this whole set of characteristics (i.e., fuel, maintenance and hydro scheduling
on one hand and commitment decisions on the other hand) has been found in the literature.
Models deciding seasonal hydro scheduling, usually based on stochastic dynamic
programming or decomposition methods, represent in detail the spatial hydro dependencies
but usually ignore the fuel and maintenance scheduling problems. Medium term fuel
scheduling is decided using a large-scale linear programming approach in several works.
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ExternE National Implementation. Spain
Maintenance scheduling has been solved by many different techniques, decomposition
techniques and integer programming among others. Combined seasonal and weekly/daily
operation of pumped units has not been addressed so far. Emissions dispatch and social costs
have been recently incorporated in production cost models and not in detail as in this tool.
9.3.1 System Description
A production cost model determines the variables defining the system operation at minimum
variable cost for the scope of the model. Let us define horizon as the point in time for which
the system operation is to be modelled and scope as the duration of the time interval to be
studied. In this medium term model, the horizon is two or three years ahead and the scope is
usually one year. The scope is divided into periods, subperiods and load levels. Typically,
periods will correspond to months, subperiods to weekdays and weekends of a month, and
load levels to peak, plateau and off-peak hours.
The load for each period is modelled as a staircase load duration curve, where an step is a load
level. Hence, generation will be constant for each load level.
Each thermal, hydroelectric, pumped-hydro and pumped-storage unit is modelled individually.
Each thermal unit is divided into two blocks, being the minimum load block the first. Heat
rate is specified by a straight line with independent and linear terms. Random outages are
deterministically modelled by derating the unit’s full capacity by its equivalent forced outage
rate. A thermal plant consists of units in a physical plant. Fuel constraints affect the fuel
consumption of domestic coal thermal plants.
Very small hydro units are aggregated. Spatial dependencies among hydro plants are
considered irrelevant to the medium term thermal generation scheduling problem and ignored.
Therefore, the variation in the hydro energy reserve of a reservoir due to the generation in a
hydroelectric plant located upstream is not taken into account.
Only the economic utilisation of pumped units is considered. This economic function includes
both the transference of energy from off-peak hours to peak hours and the alleviation of
minimum load conditions in off-peak hours or maximum load conditions in peak hours.
Additionally, these units may be operated for reliability purposes keeping their upper
reservoirs full at the beginning of each week but this operation is not represented in the model.
9.3.2 Emissions modelling
The emissions modelling of pollutants is quite recent in this type of tools and in the analysis
of electric systems operation.
Each power group with fossil fuel is modelled as a focus emitter of pollutants. For this
purpose it is necessary to define the combustion conditions (humidity, temperature, % O 2,
etc.), in the boiler and in the exit of the chimney. A detailed model needs as well the
elementary analysis of the fuel or fuels used in the unit.
142
Policy case study
In this tool four emissions are considered: the sulphur dioxide, the nitrogen oxides, the
particles and the carbon dioxide.
The legal limits are introduced in the model as constraints. The form can vary: some times it
is the concentration of pollutants in the exhaust gases from the chimney; in others it is the
total amount of emissions in a group of generators or in a single one.
9.3.3 Model Formulation
As mentioned previously this medium term production cost model performs hydro,
maintenance and fuel scheduling, seasonal operation of pumped-hydro units, weekly/daily
operation of pumped-storage units, and thermal unit commitment for a generation system. The
model is formulated as a large-scale mixed integer optimisation problem. The objective
function to be minimised is the total variable cost for the scope of the model subject to
operating constraints. These can be classified into inter and intraperiod, according to the
periods that are involved in. The interperiod constraints are associated to the co-ordination in
the use of limited resources (minimum quotas of fuel consumption, hydro inflows, seasonal
pumping, storage and generation). The intraperiod constraints deal with the system operation
in each period (thermal unit commitment, weekly/dairy pumping, storage and generation
limits).
The detailed mathematical formulation of the objective function, the constraints and the
variables involved in the problem are described elsewhere. Here, it is described their meaning.
A. Objective Functions
• Objective function #1. The first objective function is the minimisation of the fuel costs
(including independent and linear terms of the heat rate and O&M variable costs) plus
start-up costs plus storage costs of fuel stocks plus some penalties (due to non served
power, interruptibility, and reserve margin defect) for all the load levels, subperiods and
periods of the time scope.
• Objective function #2. It is the minimisation of social costs, including operation variable
costs set in objective function #1 and the environmental external costs associated to the
power generation. Usually the externalities are associated to a technology or to a particular
facility. This last is better as the environmental and its valorisation depend in the location
of the unit. The externalities can be defined in different ways: in monetary value per kWh
produced or in monetary value per tonne of pollutant produced. In this model both ways are
available.
• Objective function #3. It represents the minimisation of pollutants. The unit dispatch under
economic and environmental criteria is to reduce the pollutants emissions caused in the
fossil fuelled generation. The reduction can be reached through constraints or with
penalties in the objective function in the system operation. When this is done in the
objective function it is called emissions dispatch (the previous functions are considered
economic dispatch).
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ExternE National Implementation. Spain
B. Interperiod Constraints
These constraints tie all the periods considered in the model and correspond to maintenance,
fuel and hydro scheduling.
• Maintenance Scheduling
The units will be an integer number of periods in maintenance according to the specified
requirement. Also limits on the maximum number of thermal units simultaneously on
maintenance on the same plant and on the maximum thermal capacity simultaneously on
maintenance in any period with respect to the total installed thermal capacity are imposed.
Contiguity among the periods in maintenance is required too if more than one is specified.
• Fuel Scheduling
For each thermal plant, the stock level at the beginning of each period is a function of the
previous stock and the purchase and consumption done in the period. The initial and final
storage levels are prespecified by the user. It represents the must-buy fuel purchase mandated
by socio-economic and political considerations for domestic coal plants, although their cost
can be more expensive than other available fuels.
• Hydro Scheduling
For each hydro unit, the hydro reserve level at the beginning of each period is a function of the
previous level, the hydro inflow, pumping and generation on that period. The initial and final
hydro reserves are specified by the user.
C. Intraperiod Constraints
These constraints are internal to each period and represent the thermal unit commitment, the
security constraint based on the reserve margin, generation-demand balance and the
weekly/dairy operation of pumped-storage units.
• Reserve Margin
A power reserve margin for the peak load level of each subperiod must be met. This constraint
represents the condition imposed to provide some amount of power available to account for
increments in demand or failures of committed generation units.
• Generation-Demand Balance
Balance between generation and demand for any load level including non served power and
interruptibility.
• Pumped-Storage Units
144
Policy case study
Balance between pumped and generated energy by pumped-storage units in a period and a
reservoir limit imposed to the pumped energy.
• Thermal Generation Constraints
For each thermal unit the maximum generation is less than the maximum available capacity
and the minimum generation is greater than the minimum load. Thermal unit commitment
related constraints state that the unit’s output during higher load levels must be larger than its
generation in lower load levels and that the commitment decision in a higher load subperiod
(weekdays) must be greater than the commitment decision in a lower load subperiod
(weekends).
The above constraints enforce a minimum generation for each thermal unit committed at peak
load level. Note that since the heat rate curves are represented as linear curves, during any
load level all the committed units will be at their maximum output except one marginal unit.
D. Environmental Constraints
The limitation of emissions in power generation can have different formulation. It can focus in
the total amount of emissions, in the concentration in the exhaust gases or in the contamined
land (inmissions). The scope can also be annual, monthly, hourly, etc. Finally it can refer to
the units individually or to a group of them.
This model reproduces the Spanish power system through the following types of contraints:
• Maximum SO2 emissions in the old and new units
• Maximum NOX emissions in the old and new units
• Maximum particles emissions in new units
• Minimum rate of desulphurization
• etc.
E. Variables
All the variables involved in the previous formulation are: maintenance decisions, fuel stock
levels, hydro productions, consumption of pumped-hydro units, hydro energy reserves,
commitment decisions of thermal units, thermal generations, generation and consumption of
weekly/dairy pumped-storage units, non served power, interruptible power and reserve margin
defect.
The initial and final fuel stocks levels for each thermal plant and the initial and final energy
reserves for each hydro unit are predefined by the user.
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ExternE National Implementation. Spain
The variables regarding operation of the pumped-hydro and pumped-storage units are defined
only for the periods, subperiods and load levels where they are meaningful according to the
system operation.
The variables commitment and maintenance decisions for thermal units cause the problem to
be mixed integer with the associated difficulty to be solved. Codes with such feature are
needed, such as CPLEX or OSL for example.
9.3.4 Implementation
The model has been implemented in GAMS version 2.25, a mathematical specification
language specially indicated for the solution of optimisation problems. It allows the creation
of large and complex problems in a concise and reliable manner. This language lets the user to
concentrate on the modelling problem by eliminating the writing details of special code in the
preliminary stages of algorithmic development. GAMS is flexible and powerful. This
flexibility is crucial in the development and test of new algorithms.
The problem as previously formulated is a large-scale mixed integer optimisation problem. Its
size for the Spanish electric power system is about 10000 rows, 9000 variables, being 2500
discrete, and 38000 non zero elements in the constraints matrix. In particular recent
developments in branch and bound and interior point methods are specially suited for the
solution of these problems. Several MIP solvers can be used in conjunction with the GAMS
language, CPLEX and OSL for example.
Careful attention when solving a large-scale optimisation problem should be paid to the
scalation of constraints and variables. So GW is taken as the natural unit for power, TWh for
energy, Tpta for monetary unit and kTcal for heat consumption.
The implementation of this model and its resolution using direct solution of the global
problem using this compact and elegant algebraic language takes only 1400 lines of code. The
model can be used in any hardware platform where GAMS and the solvers were available.
Currently, a personal computer is being used.
The model presented is being used as a economic and operations planning tool representing
the large-scale Spanish electric power system. The model provides the minimum variable cost
subject to operating constraints (generation and fuel constraints). Generation constraints
include power reserve margin with respect to the system peak load, generation-demand
balance, maintenance scheduling, hydro energy scheduling, and generation limitations. Fuel
constraints include minimum consumption quotas and fuel scheduling for domestic coal
thermal plants. The relevant decision variables and the real operation of the power system are
adequately represented. Two types of decisions are addressed: interperiod decisions are those
regarding resources planning for multiple periods, (i.e., maintenance scheduling, yearly hydro
energy scheduling, seasonal operation of pumped-hydro units, and fuel scheduling) and
intraperiod decisions correspond to a generation optimal economic dispatch (i.e., weekly/daily
operation of pumped-storage units and commitment decisions of thermal units).
146
Policy case study
The operations planning problem is formulated as a large-scale mixed integer optimisation
problem. The model has been formulated in GAMS, a modelling language specially indicated
for the solution of optimisation problems, and solved by using a simplex or interior point
method with different well-known solvers. The model is a very powerful and flexible tool
easily adaptable to any electric power system.
9.4 Case Study: Spanish Power System
According to data extracted from 1994 statistical records, the Spanish power system met a
maximum peak load of 25336 MW and a yearly energy demand of 145670 GWh. The
installed generation capacity is 42096 MW (16110 MW are hydro, 10675 MW coal, 7910
MW oil/gas and 7401 MW nuclear).
There are about 71 thermal generators (8 nuclear, 36 coal and the remaining oil/gas). Their
production is about 80 % of the total generation.
There are 70 hydro units with capacity greater than 5 MW and annual energy production
greater than 100 GWh, that can be grouped into about 10 basins. In the model they have been
used units smaller than these. The maximum capacity at the same location is 915 MW. They
produce as an average about 20 % of the total generation, ranging in between 13 % and 28 %,
depending on the hydrology.
There are 8 pumped storage units, but their impact on annual energy production is minimum
(about 1%).
The model has been designed to represent the Spanish electric power system. The
characteristics of the system regarding time division and number of elements are presented in
the first table.
The time required to run this model depends on the option been solved. For the electric power
system shown two options have been executed, the first one has a hydro units aggregation and
discrete commitment and maintenance decisions and in second one the hydro units has been
treated individually but there is a relaxation of the discrete decisions. The following table
shows the sizes of the problem and the time consumption. Time is expressed in seconds,
corresponding to a PC 486 at 33 MHz.
Periods
Subperiods/period
Load levels/subperiod
Coal units
Fuel-oil units
Natural gas units
Nuclear units
Thermal plants
Hydro/Pumped-Hydro units
Pumped-Storage units
12
2
3 and 2
36
22
5
9
16
122
8
147
ExternE National Implementation. Spain
9.5 Externalities of the Spanish Electrical System
The externalities of the Spanish electricity system have been calculated in the previous section
on Aggregation. Details for these calculations may be found there.
9.5.1 Fossil fuels power units
Externalities of several plants have been calculated, extrapolating the results for the rest of the
system units. In the extrapolation some attributes for each plant have been considered:
• location
• fuel
• technology
These two last aspects determine the emissions rate for the main pollutants. This rate is the
most important factor of the extrapolation. System units characteristics are described in the
next pages.
9.5.1.1 Thermal units data
For each thermal unit:
• Thermal unit identification
• Maximum and minimum rated capacity (MW)
• Heat rate (linear and independent terms)
The parameters A and B are the linear and independent terms respectively of the heat
rate curve of each power plant. Th./MWh and Th./h are the natural units taken for each
term.
• Commitment hours in 1996 operation
The time when the unit is committed producing between the minimum and the maximum
rated capacity.
• Energy production in 1996 operation (GWh).
148
Policy case study
Table 9.Error! Unknown switch argument. Coal units description (1996).
Coal and lignite
Units
Anthracite
Aboño 1
Aboño 2
Lada 3
Lada 4
Soto 1
Soto 2
Soto 3
Narcea 1
Narcea 2
Narcea 3
Anllares
Compostilla1
Compostilla2
Compostilla3
Compostilla4
Compostilla5
La Robla1
La Robla2
Guardo1
Guardo2
Puertollano
Puentenuevo
Imported coal
Pasajes
Litoral
Los Barrios
Black lignite
Serchs
Escatrón
Teruel1
Teruel2
Teruel3
Escucha
Brown lignite
Puentes1
Puentes2
Puentes3
Puentes4
Meirama
Maximum
capacity
(MW)
Minimum
capacity
(MW)
A
(Th./kWh)
B
(Th./h)
Commitment
hours
1996
Energy
(GWh)
1996
360
543
155
350
68
254
350
65
154
350
350
141
141
330
350
350
270
350
148
350
220
313
200
256
70
180
48
160
175
35
85
220
170
65
70
160
175
175
140
220
74
150
80
150
2210
2130
2390
2210
2670
2210
2210
2670
2390
2210
2210
2390
2390
2210
2210
2210
2210
2210
2390
2210
2210
2210
55000
77000
31000
55000
15000
44000
55000
15000
31000
55000
55000
31000
31000
55000
55000
55000
44000
55000
31000
55000
44000
55000
8366
7589
5700
7651
0
7921
7380
0
2828
7111
7756
7238
1493
6765
7393
7393
5492
6162
0
6192
6346
7000
2788
3804
757
2401
0
1902
2327
0
384
2265
2586
1008
105
2213
2588
2588
1296
1947
0
1843
1187
1925
214
550
550
105
180
180
2130
2130
2130
77000
77000
77000
7921
8397
8453
1570
4328
4430
160
80
350
350
350
160
80
44
180
180
180
80
2410
2140
2260
2260
2260
2410
33000
19000
57000
57000
57000
33000
3426
6534
7486
7452
7453
4856
476
492
2601
2594
2594
702
350
350
350
350
550
230
230
230
230
270
2390
2390
2390
2390
2390
59000
59000
59000
59000
83000
6518
3393
6205
6545
4744
2077
1081
1978
2095
2262
149
ExternE National Implementation. Spain
Table 9.Error! Unknown switch argument. Fuel-oil units description (1996).
Fuel-oil
Units
San Adrián2
Algeciras1
Algeciras2
Escombreras1
Escombreras2
Escombreras3
Escombreras4
Escombreras5
Aceca1
Aceca2
Sabón1
Sabón2
Castellón1
Castellón2
Badalona 1
Badalona 2
Colón1
Colón2
Colón3
Maximum
capacity
(MW)
350
220
533
70
70
140
289
289
314
314
120
350
542
542
172
172
70
148
160
Minimum
capacity
(MW)
100
66
160
20
20
4
100
100
61
61
40
100
140
140
55
55
22
43
48
A
(th/kWh)
B
(th/h)
2190
2130
2190
2650
2650
2360
2190
2190
2190
2190
2360
2190
2120
2120
2360
2360
2650
2360
2360
48000
77000
38000
14500
14500
29000
43000
43000
43000
43000
29000
48000
77000
77000
29000
29000
14500
29000
29000
Commitment
hours
1996
0
216
0
0
0
0
0
0
354
0
0
0
0
0
0
0
0
555
0
Energy
(GWh)
1996
0
39
0
0
0
0
0
0
88
0
0
0
0
0
0
0
0
67
0
Table 9.Error! Unknown switch argument. Natural gas units description (1996).
Natural gas
Units
Besos1
Besos2
Foix
San Adrián1
San Adrián3
Elcogas
Maximum
capacity
(MW)
150
300
520
350
350
335
Minimum
capacity
(MW)
45
60
100
100
100
0
A
(th/kWh)
B
(th/h)
2310
2130
2060
2130
2130
1260
25000
37000
67000
42000
42000
106000
Commitment
hours
1996
0
516
436
564
0
1790
Energy
(GWh)
1996
0
123
180
161
0
268
Table 9.Error! Unknown switch argument. Nuclear units description (1996).
Nuclear
Units
Asco1
Asco2
Almaraz1
Almaraz2
Cofrentes
Vandellós
Garoña
Trillo
J. Cabrera
150
Maximum
capacity
(MW)
930
930
931
931
990
1004
460
1066
160
Minimum
capacity
(MW)
0
0
0
0
0
0
0
0
0
A
(th/kWh)
B
(th/h)
1000
1000
1000
1000
1000
1000
1000
1000
1000
0
0
0
0
0
0
0
0
0
Commitment hours Energy (GWh)
1996
1996
8147
6093
6093
8147
7477
7477
6785
7477
7477
7577
5667
5671
7581
7402
7507
3121
7971
1196
Policy case study
For each fuel of all thermal units:
• Analysis of primary and secondary fuels
The immediate analysis of any fuel is a simple composition used in commercial
terms. It is composed by four components: humidity, ash, volatile and carbon. It is
normally accompanied by the percentage of sulphur in the fuel.
%H humidity
%C ash
%V volatile
%Cf carbon
%S
sulphur
• Maximum use of the secondary fuel (%)
It is the maximum percentage mix with the primary fuel that can be burned in the
boiler of each unit.
For each technology:
• Specific SO2 emissions rate (g/kWh) (1996)
• Specific NOx emissions rate (g/kWh) (1996)
• Specific CO2 emissions rate (g/kWh) (1996)
• Specific TSP emissions rate (g/kWh) (1996)
Table 9.Error! Unknown switch argument. Specific SO2, NOx, CO2 and TSP emissions rates
(g/kWh) (1996).
Technology
anthracite
lignite 1
lignite 2
imported coal
fuel-oil
natural gas
SO2
(g/kWh)
7.8
37.9
26.8
3.5
5.1
0.0
NOx
(g/kWh)
4.0
3.2
2.5
2.5
1.6
1.6
CO2
(g/kWh)
924
936
1108
855
781
781
TSP
(g/kWh)
0.6
0.5
0.5
0.1
0.2
0.2
9.5.1.2 Externalities of fossil fuels units
As mentioned, the externalities of the thermal units have been quantified extrapolating the
results obtained for some of the most representative plants. The units considered for the first
analysis are:
151
ExternE National Implementation. Spain
• Puentes de G.R. (brown lignite)
• Teruel (black lignite)
• Compostilla (anthracite)
• Aboño (anthracite)
• Pasajes (imported coal)
• Litoral de Almería (imported coal)
• Puertollano (natural gas)
• Colón (fuel-oil)
• Foix (natural gas)
These units have been chosen considering their geographic location. For them, health damages
at regional scale due to SO2, NOX and TSP emissions have been assessed. In this study, only
health damages have been included considering that other quantifiable impacts are negligible excepting the possible impact of global warming due to CO2 emissions-; it is concluded that
the considered impacts are sufficient for our analysis.
The externalities obtained are shown in the next tables. There are two types of results: damage
estimates in mECU/t of pollutant emitted and in mECU/kWh produced. The second is
obtained using the specific emission rate of each unit and pollutant. The model uses the first
type of estimation in order to choose one or other fuel considering its environmental,
economic or technical characteristics in each unit.
152
Policy case study
Table 9.Error! Unknown switch argument. Externalities of the Spanish Power System. Coal
units.
Unit
Aboño 1
Aboño 2
Lada 3
Lada 4
Soto Ribera 1
Soto Ribera 2
Soto Ribera 3
Narcea 1
Narcea 2
Narcea 3
Anllares
Compostilla 1
Compostilla 2
Compostilla 3
Compostilla 4
Compostilla 5
La Robla 1
La Robla 2
Guardo 1
Guardo 2
Puertollano
Puentenuevo
Pasajes
Litoral
Los Barrios
Serchs
Escatrón
Teruel 1
Teruel 2
Teruel 3
Escucha
Puentes 1
Puentes 2
Puentes 3
Puentes 4
Meirama
Damages
mECU/kWh
76.02
75.90
90.18
84.44
73.13
90.18
82.23
81.99
86.54
84.32
74.49
73.25
74.49
74.49
74.49
74.49
73.25
73.83
69.20
69.20
82.34
83.73
64.81
35.65
26.84
149.92
47.16
180.20
180.94
181.42
221.39
99.74
102.41
99.74
99.44
128.42
Damages
ECU/t SO2
6991
6991
6991
6991
6991
6991
6991
6991
6991
6991
5813
5813
5813
5813
5813
5813
5813
5813
5813
5813
6361
6361
9583
5657
4219
7450
7450
7450
7450
7450
7450
5073
5073
5073
5073
5073
Damages
ECU/t NOX
8170
8170
8170
8170
8170
8170
8170
8170
8170
8170
6554
6554
6554
6554
6554
6554
6554
6554
6554
6554
7556
7556
12076
6136
4651
4823
4823
4823
4823
4823
4823
2918
2918
2918
2918
2918
Damages
ECU/t TSP
6121
6121
6121
6121
6121
6121
6121
6121
6121
6121
4876
4876
4876
4876
4876
4876
4876
4876
4876
4876
6483
6483
10780
5083
4418
6847
6847
6847
6847
6847
6847
5262
5262
5262
5262
5262
153
ExternE National Implementation. Spain
Table 9.Error! Unknown switch argument. Externalities of the Spanish Power System. Fueloil units
Unit
San Adrián 2
Algeciras 1
Algeciras 2
Escombreras 1
Escombreras 2
Escombreras 3
Escombreras 4
Escombreras 5
Aceca 1
Aceca 2
Sabón 1
Sabón 2
Castellón 1
Castellón 2
Badalona 1
Badalona 2
Colón 1
Colón 2
Colón 3
Damages
mECU/kWh
58.97
29.84
29.84
39.68
39.68
39.68
39.68
39.68
45.83
45.83
31.59
31.59
58.97
58.97
34.87
34.87
34.87
34.87
34.87
Damages
ECU/t SO2
8427
4219
4219
5657
5657
5657
5657
5657
6361
6361
5073
5073
8427
8427
8427
8427
4820
4820
4820
Damages
ECU/t NOX
8983
4651
4651
6136
6136
6136
6136
6136
7556
7556
2918
2918
8983
8983
8983
8983
5753
5753
5753
Damages
ECU/t TSP
8107
4418
4418
5083
5083
5083
5083
5083
6483
6483
5262
5262
8107
8107
8107
8107
5426
5426
5426
Table 9.Error! Unknown switch argument. Externalities of the Spanish Power System.
Natural gas units
Unit
Besós 1
Besós 2
Foix
San Adrián 1
San Adrián 3
Elcogas
Damages
mECU/kWh
14.37
14.37
14.37
14.37
14.37
3.02
Damages
ECU/t SO2
8427
8427
8427
8427
8427
6361
Damages
ECU/t NOX
8983
8983
8983
8983
8983
7556
Damages
ECU/t TSP
8107
8107
8107
8107
8107
6483
9.5.2 Nuclear units
As mentioned before, the values for nuclear and hydro fuel cycles have been extrapolated
directly from European values, and so the results for these electricity sources should be
regarded with caution. Two different values are used for the two nuclear technologies.
154
Policy case study
Table 9.Error! Unknown switch argument. Externalities of Spanish Power System. Nuclear
units
Unit
Asco 1
Asco 2
Almaraz 1
Almaraz 2
Cofrentes
Vandellós
Garoña
Trillo
J. Cabrera
Technology
PWR
PWR
PWR
PWR
BWR
PWR
BWR
PWR
PWR
Damages
mECU/kWh
2.0
2.0
2.0
2.0
8.0
2.0
8.0
2.0
2.0
In the nuclear generation, only damages by kWh produced are considered.
9.5.3 Hydro units
In the hydraulic generation the externalities have not been calculated for each unit specifically.
For the hydro cycle (hydro and pumped-storage units), externalities have been extrapolated
directly from European values. Even the pumped-storage units have this same value per kWh
generated.
Table 9.Error! Unknown switch argument. Externalities of Spanish Power System. Hydro
units
All units
Damages
mECU/kWh
2.0
9.5.4 Other units
Wind and biomass generation technologies are of very little importance in the Spanish system.
Thus, they have not been incorporated. Cogenerators produce a significative amount of energy
but they have not been considered in this study because its externalities have not been
quantified for the moment.
9.6 Analysis of the operation of the Spanish Power System
To quantify the total external costs of the power generation in the operation of the Spanish
system in 1996, 5 dispatch strategies have been studied:
155
ExternE National Implementation. Spain
• Current centralised dispatch, with optimisation of the standard variable costs, with and
without domestic coal constraints due to energy policies (A.1 and A.2)
• Minimisation of the standard variable costs, including the environmental externalities, with
and without domestic coal constraints due to energy policies (B.1 and B.2).
• Minimisation of the standard variable costs, including the 30% of the environmental
externalities, with and without domestic coal constraints due to energy policies (C.1 and
C.2).
A.1 and A.2 strategies consist in operating the system being the objective function the
minimisation of the standard variable costs of operation (objective function #1) with the
operation, reliability and environmental constraints described in section 9.3.3. Case A.1 is the
reference case for the later comparison with the other strategies.
Strategies B.1 and B.2 have both the objective function (#2) of minimisation of the social
costs of the system operation but B.1 includes the constraints of minimum consumption of
domestic coal due to energy policies and B.2 does not.
In cases C.1 and C.2 the formulation is similar to cases B being the only difference that cases
C only consider the 30% of the externalities calculated for the Spanish power system. The
interest of these strategies is because this is the percentage estimate that can affect the Spanish
system, being a first approximation for the external costs generated by the power system in
Spain.
In all cases the values for the externalities are held in mECUs by ton of emitted pollutant,
except in the nuclear and hydro technologies where the values are in mECUs per kWh
generated.
156
Policy case study
9.7 Results and conclusions
Table 9.Error! Unknown switch argument. CASE A. Operation results in 1996 of the Spanish
power system
1996
Case A.1
Case A.2
Total variable costs
(million ptas.)
335,478
315,957
Total external costs
1,314,709
803,580
TOTAL SOCIAL COSTS
1,650,187
1,118,537
30,352
51,133
8,957
8,780
33,575
10,436
61,747
0
893
30,135
51,133
7,332
966
39,837
10,490
58,625
2,805
893
142,196
142,196
Pumping consumption
1,930
1,619
EMISSIONS of SO2 (kt)
1,105
678
EMISSIONS of NOX (kt)
219
214
EMISSIONS of TSP (kt)
23.7
20
EMISSIONS of CO2 (kt)
77,016
77,616
NET GENERATION (GWh)
hydro
nuclear
brown lignite*
black lignite*
anthracite*
imported coal
total COAL
fuel-oil
natural gas
NET GENERATION (GWh)
* are referred to the total production of the units which main fuel is this one, although they use another.
157
ExternE National Implementation. Spain
Table 9.Error! Unknown switch argument. CASES B.1 and B.2. Operation results in 1996 of
the Spanish power system
1996
Case B.2
Total direct variable costs (million ptas.)
Total external costs
364,851
1,170,439
366,240
206,732
TOTAL SOCIAL COSTS
1,535,290
572,972
29,451
51,133
8,588
8,760
27,677
0
45,024
14,334
2,895
31,293
51,133
0
0
3,083
8,583
11,667
38,988
12,388
142,196
142,196
643
3,274
1,058
166
EMISSIONS of NOX (kt)
164
59
EMISSIONS of TSP (kt)
19.8
1.7
EMISSIONS of CO2 (kt)
73,359
48,178
NET GENERATION (GWh)
hydro
nuclear
brown lignite
black lignite
anthracite
imported coal
total COAL
fuel-oil
natural gas
NET GENERATION (GWh)
Pumping consumption
EMISSIONS of SO2 (kt)
158
Case B.1
Policy case study
Table 9.Error! Unknown switch argument. CASES C.1 and C.2. Operation results in 1996 of
the Spanish power system
1996
Case C.1
Case C.2
Total direct variable costs (million ptas.)
352,212
354,989
Total external costs
358,711
69,891
TOTAL SOCIAL COSTS
710,923
424,880
29,253
51,133
10,283
8,772
27,694
4,417
51,166
9,254
1,794
29,253
51,133
0
0
6,957
8,834
15,791
34,721
11,657
142,196
142,196
360
359
1,079
175
EMISSIONS of NOX (kt)
177
70
EMISSIONS of TSP (kt)
21
2.6
EMISSIONS of CO2 (kt)
74,557
49,623
NET GENERATION (GWh)
hydro
nuclear
brown lignite
black lignite
anthracite
imported coal
total COAL
fuel-oil
natural gas
GENERATION (GWh)
Pumping consumption
EMISSIONS of SO2 (kt)
Table 9.Error! Unknown switch argument. Coal consumption among the different cases (kt)
brown lignite
A.1
9,635
A.2
6,208
B.1
9,635
B.2
0
C.1
9,635
C.2
0
159
ExternE National Implementation. Spain
black lignite
anthracite
imported coal
total COAL
4,092
13,720
9,566
36,552
0
7,999
16,373
30,580
4,092
13,720
3,338
30,785
0
0
4,038
4,038
4,092
13,720
5,826
33,273
0
0
5,523
5,523
• CASES A.1 and A.2
Strategy A.1 is the operation in 1996 of the Spanish power system with constraints on the
domestic coal (minimum consumption) due to energy policy. This compulsory consumption is
distributed among the different coal areas. The domestic coal quota for the whole power
system is 27.5 kt, being black lignite (4 kt), anthracite (14 kt) and brown lignite (9.5 kt).
The system operation under minimum variable costs in 1996 gives a result of 335,478 million
ptas. The distribution of net energy generated by the different technologies is the following:
• coal
43%
• nuclear
35,5%
• hydro
21%
• natural gas 0,5%
The total SO2 emissions are 1,105,000 tons. This amount is distributed among the different
technologies as follows:
• brown lignite:
272 kt
• black lignite:
333 kt
• anthracite:
295 kt
• imported coal:
49 kt
• natural gas:
0.8 kt
As we see, it is the black lignite which produces the biggest amount of this kind of pollutant.
However, the energy generated by this technology (8,780 GWh) is less than the energy
produced by the anthracite units (33,484 GWh). This results in very different emissions rates
of SO2 by kWh generated: 28.8 g/kWh for brown lignite, 38.2 g/kWh for black lignite, 9.6
g/kWh for anthracite and 4.8 g/kWh for imported coal.
• CASES B.1 and B.2
160
Policy case study
When the units dispatch is done minimising social costs -direct costs and externalities-, the
units firstly operated will be those with low social cost. Those units should be obviously the
cleaner ones. Strategies B.1 and B.2 have been analysed following this objective.
To quantify the external costs derived to domestic coal constraints imposed to the system,
strategy B.1 is done with these constraints and B.2 is done without them. Looking at Error!
Unknown switch argument. and considering that the total direct variable costs of both
strategies are similar, we can obtain the external costs of the Spanish coal constraints imposed
to the power system dispatch: 963,707 million ptas.
The total social costs in case B.1 is 1,535,290 million ptas. and in B.2 572,972 being the coal
consumption 30,785 kt and 4,038 kt respectively. This is basically the cause of the SO2
emissions reduction in strategy B.2: from 1,058 to 166 thousand t.
• CASES C.1 and C.2
Strategies C.1 and C.2 have been analysed minimising also the social costs but this time
adding to the direct costs only the 30% of the externalities. Considering this level of
externalities, the external costs of the Spanish coal constraints imposed to the power system
dispatch are in this case 286,043 million ptas.
As a general conclusion, it has to be remarked the significant change in the electricity
dispatching system when externalities are introduced. Lignites, due to their high sulphur
content, disappear from the system, and the contribution of national coal is greatly reduced.
However, here it has to be noted that this result, that is, the minimization of social costs, is
only achieved if other constraints are removed from the dispatching model. Of these, the
major one is the compulsory consumption of national coal. As may be seen, if this constraint
is not removed, the change induced by the introduction of externalities into the system is the
elimination of imported coal, which is indeed cleaner than national coal. This change is very
small indeed, since the contribution of imported coal is quite small.
In fact, it may be said that, if the constraint is not removed, the introduction of externalities
into the dispatching system produces hardly any change, as may be observed from cases A.1,
B.1, and C.1. When it is eliminated, external costs are greatly reduced, even if their
minimisation is not an objective. This may be seen in case A.2., where the constraint is
removed but externalities are not included. In this case, external costs are reduced, simply by
the change from national coal and lignites to imported coal. However, eliminating the
constraint by itself does not minimize social costs, externalities have to be included, as shown
in cases B.2 and C.2. In these cases, national coal is completely eliminated, being substituted
by fuel-oil and gas.
Nevertheless, it has to be reminded that here only environmental externalities have been
assessed. National coal and lignites have also several advantages, such as their contribution to
energy security, and their support of local economies in mining regions. Therefore, in order to
161
ExternE National Implementation. Spain
decide whether the constraint mentioned above is justified or not, a full analysis of these
aspects should be carried out.
162
10. CONCLUSIONS
The major conclusion of this study may be that, in spite of the uncertainties underlying the
analysis, a large set of externalities for electricity generation has been calculated, and
therefore, a first attempt towards the integration of environmental aspects into energy policy
may be carried out, taking into account all the limitations which will be explained later.
And it has to be noted that, although they are considered sub-totals, that is, that there are still a
number of impacts to be quantified in monetary terms, the figures obtained are already
significant, specially if global warming damages are taken into account.
Moreover, it has to be reminded that the technologies assessed for individual fuel cycles are
state-of-the-art technologies, equipped with environmental devices. In the case of the coal fuel
cycle, for example, even though the power plant is equipped with ESP, FGD, or low NOx
burners, the externalities estimated are almost as large as the private generation cost. If the full
range for global warming damages is considered, damages are almost thrice the private costs.
If older technologies are considered, such as those assessed for the aggregation exercise, the
externality per kWh rises to quite high values, up to 4 times the private cost, in the case of
high-sulphur lignites (even if global warming damages are not included).
Therefore, it might be concluded that the external costs of some fuel cycles are high enough to
affect energy policy decisions. However, here it has to be reminded that the methodology has
still a large number of uncertainties.
These uncertainties create some difficulties for using the results directly for policy-making.
Several aspects should be improved, mainly the estimation of global warming damages.
Atmospheric dispersion models, which, at least for the Spanish case, should account for the
complex topographic conditions are also a controversial aspect. An important issue which
should also be studied is the relationship between atmospheric pollution and chronic
mortality.
Regarding global warming damages, its range of estimated results is so broad that it
dominates the results for fossil fuel cycles. This produces that, when the higher estimate for
global warming damages is considered, fossil fuels cannot compete with nuclear, or
renewables. Therefore, the high estimates for global warming benefit to a large extent these
energy sources.
Considering that chronic mortality is, by large, the major externality, besides from global
warming damages, of fossil fuel cycles, the fact that there is only one exposure-response
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ExternE National Implementation. Spain
function for its estimation, and that this function comes from the US, without being checked
in Europe, adds a lot of uncertainty to the final results.
The valuation of human life is also a significant factor affecting the results, as it determines
the human health externality, which, as said before, is the major one. Controversy still exists
around this issue, and, in spite of the modifications introduced in the valuation of life by the
Core Project, the values assigned are still contested outside the project.
All these uncertainties affect the individual fuel cycles examined. For the aggregation of
results to the whole electricity sector, more problems arise, such as the transferability of
results from one site to another, or the accounting of effects for which there is a threshold.
Indeed, differences in the damages per t of pollutant emitted between different sites are quite
large, so the direct transfer of results from one site to another is not reasonable. In the case of
nuclear or hydro, this transferability is even more difficult.
Hence, it is recommended to use the results provided by this report only as background
information. This background information might be very useful for establishing economic
incentives, such as environmental taxes, or subsidies for renewable energies, or for energy
planning measures. However, as said before, results should not be used directly, until the
methodology is refined.
For what results may be used directly, though, is for planning processes where the quantitative
results are not so relevant. This is the case, for example, of the optimization of plant site
selection, or for choosing among different energy alternatives. As may be seen in this report, it
is clear that gas is a much cleaner energy source than coal, and that the mix of biomass with
lignites results in less environmental damages than those of lignites alone. As might be
expected, renewable energies such as wind are the cleanest energy sources.
Another possible use of these results is the analysis of the costs and benefits of the
implementation of environmentally friendly technologies. Results show that fluidized-bed
combustion, or FGD, reduce pollutant emissions, and so reduce environmental damages. As
far as the more certain damages avoided compensate the costs of the implementation, the
installation of these devices will be justified.
Although further research is required to refine the methodology, and thus, to produce more
precise results, removing the existing uncertainties, this report is the first comprehensive
attempt to estimate the externalities of electricity generation in Spain. Hence, it is believed
that it will contribute to a large extent to the integration of environmental aspects into energy
policy.
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