Chapter 5 on energy balances

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Chapter 5 on energy balances
Ann Christin Bøeng,
Senior adviser
Division for energy and environmental statistics, Department of
economics, energy and the environment
Statistics Norway
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Outline for this presentation
• Work process with the chapter
• Comments from last Oslo group meeting in Helsinki
• Current structure in the chapter and changes since last
meeting
• Comments from the virtual meeting in April this year
• Questions
• First annotated outline of the chapter: Does the chapter
follow UNSD’s planned outline.
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Comments and discussion on last OG meeting
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The first draft of chapter 5 was presented in Helsinki in October 2012.
Statistics Norway wrote the main part of the first draft.
The following countries / organizations volunteered to contribute;
Country/Organization
Representative
IEA
Karen Treanton
Canada/Statistics Canada
Andy Kohut
China/ National Bureau of Statistics of China
Xie Xin
Cameroon/Ministère de l'Energie et de l'Eau (MINEE)
Defo Wafo Sylvain
Congo/Ministère de l'Energie
Willy Kipoy S. Musalu
Ghana/Energy Commission of Ghana
Salifu Addo
UK/UK Department of Energy and Climate Change (DECC)
Iain MacLeay
UNSD
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Some of the comments from the meeting in Helsinki were
the following:
• Start with description of energy commodity balance and
then explain how to convert it to an energy balance.
• Ensure that the chapter follows IRES
• It was a discussion whether the chapter should explain how
to estimate the renewable energy share in the balance
• IRES sais that the energy balance should contain an ”of this
renewable” column, and it was agreed to explain this in the
chapter.
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Several comments on the chapter (continues)
• Give more practical guidance on how to compile the
balance
• Explain better what an energy balance is and what is the
purpose with it.
• Include more country practices or refer to places where
practical examples on how to do things could be found
• Needs of some restructuring
• Describe better conversion from physical units to energy
units.
• Describe ”energy losses” better!
• Make it more easy to understand
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Changes made in the chapter
• A somewhat modified draft was published on the
virtual meeting the 15th. April this year.
There are now 4 main parts in the chapter and an appendix.
• Part A: Introduction / Importance of energy balances. (one
page)
• Part B: General information pertinent to both commodity
balances and energy balances (describes flows etc.)
• Part C: Compilation of energy balances.
• Part D: Country spesific examples
• Appendixes
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Part B: Information pertinent to both balances and commodity balances
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1. Level of detail
2. Yearly, quarterly or monthly balances?
3 Timeliness, preliminary and final balances
4. Scope of commodity balances and energy balances
- 4.1 Energy products (SIEC)
- 4.2 Energy flows
5 : Domestic supply and transfers (describes prod., bunkers etc.)
6. Transformation (examples on transformation processes)
7: Energy industries own use
8: Losses
9; Final consumption
10: Statistical difference
11: Possible elements for reconciliation
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Part C Compilation of energy balances
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1 Calculating an energy balance
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5 . Hydro pumped storage plants: Different treatment in balances and
commodity balances
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6 Example of an energy balance (EB for Austria as example)
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8 Presentational issues in an energy balance (transformation, transfer)
2 Net or gross calorific values? (NCV recommended)
3 Choice of the primary energy form
4 Calculation of the primary energy equivalent : How to calculate
nuclear, hydro, solar etc., when only the electricity produces is known.
7 Checking the energy balance (checking transformation losses,
statistical difference, generation efficiency)
9 How to calculate the renewables column
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Part D Country-specific examples
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1. Statistics Norway’s energy balance
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Appendix A. Heat production from heat pumps
2. Statistics Austria’s energy balance
3. Aggregated energy balance for the United Kingdom
Appendix B. Calculation of the primary energy equivalent
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Changes in the chapter
• Most modifications was done by me and Karen Treanton in
IEA (who has now retired- gone sailing)
•
The current draft now starts with describing commodity
balances, before explaining how to compile energy
balances.
- One challenge was that existing recommendations on
how to compile commodity balances are limited. Appendix
C in IRES gives only a short general description of this.
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Commodity balances
• Energy commodity balances varies among countries.
• Some countries present commodity balances separately for
each energy product, while others present complete
commodity balances for all products.
• Most countries do not include the primary form of electricity
and heat (hydro, wind, nuclear) in their commodity
balances, but Eurostat does.
• Most countries and institutions does also include both
primary and secondary energy production in the top row in
the commodity balance (but not Eurostat)
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Several changes
• The chapter gives a description on common practices for
compiling commodity balances.
• We approve that layouts may differ of various reasons, such
as different preferences or energy situations in the countries
• Furthermore; There is a lot of common elements in the
energy balance and commodity balance;
• Most of the flows and the products are the same, but it is
just restructured, and presented in different units.
• That is why we use the following title on part B of the
chapter (which describes flows and contents in the balance)
• - Information pertinent to both balances and commodity
balances
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Other changes in the draft
• There are added more practical examples on certain
technical issues, - such as calculating hydro and
geothermal in the balance.
• To convert from commodity balances to energy balances, it
is necessary to calculate the primary energy equivalent
(hydro, wind, sun, nuclear etc.) on basis of the output of
electricity and heat.
• This is described in part part C in the chapter.
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Physical energy content method
• The partial substitution method and physical energy content
method is described. The physical energy content method is
recommended.
• It is added calculation example on how to calculate the
primary energy equivalent for hydro, nuclear, wind, etc. on
basis of electricity and heat output (in table 5.5)
• This is simply done by converting the primary energy
products to a joint unit; Petajoule
• No losses are assumed for hydro and wind, but for nuclear
and geothermal it is assumed losses (efficiency = 33 % for
nuclear and 10 % for electricity from geothermal)
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Table 5.5 Calculation of primary energy using
the physical energy content method
Non-combusted products
Electricity output
(GWh)
Equation
Primary energy equivalent
in PJ
Nuclear
0
=(0*.0036)/0.33
0
Hydro
41596
=(41596-3190)*0.0036
138.26
(of which pumped storage)
3190
Solar PV
not included in energy
balance
89
=89*0.0036
0.32
2064
=2064*0.0036
7.43
Geothermal
1
=(1*0.0036)/0.1
0.04
Solar thermal
0
=(0*0.0036)
0
Heat output (TJ)
Equation
Primary energy equivalent
in PJ
538
=(538/1000)/0.5
1.08
0
=(0/1000)/0.5
0
Wind
Non-combusted products
Geothermal
Solar thermal
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Conversion
• This means that for 10 PJ electricity produced from
geothermal we need an input of 100 PJ geothermal.
• These efficiencies are provided by IEA. However, I think the
efficiencies used may vary among countries.
Conversion from tonnes to PJ;
• It is also added tables (table 5.4) that shows how to convert
oil products from physical units to energy units (by
multiplying with the net calorific value) for energy balance
purposes.
• Net calorific values are taken from IRES.
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Validation rules
• It is included several validation practices in the balance;
- Such as checking efficiency in transformation processes
(for instances refinery plants) . Losses should not be too
large or too small and it should not be an energy gain.
• In refineries the losses in the transformation process from
crude oil to oil products, should be around 0.5-2 per cent.
• It is also added a table with expected
generation efficiency in thermal power
plants and heat plants.
• Statistical differences is another useful
check for the balance
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Other changes
• There is included a section on how to calculate the
renewable part of the balance in the chapter.
• This is a challenge for electricity, because
it might be traded among countries.
• A few countries are very dependent of
imported electricity
• In the chapter we propose that countries
should calculate the RE part of electricity
according to the renewable production
in the country.
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Renewable column
• However, if the country are very dependant of electricity
imports, it might be wrong to calculate this share on basis of
production.
• One solution is to assume that all imported electricity is nonrenewable.
• Another possibility is to estimate the RE-share in
imported
electricity (on basis of production technology in the
countries) and take also this into account . This is proposed
in cases were import dependency of electricity is high.
• Other changes in the draft:
• There are added country practices; for Austria, Norway,
Azerbaijan and UK.
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Comments during the virtual meeting
• During the virtual meeting from 15. April 2013, we got
comments from UK, Poland, Ireland, UNSD and Egypt
• First of all;
• Many thanks to all who have given comments;
• They were all very useful
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Some of the comments
• Proposal to recommend countries to include heat pumps in
the energy balance
• Better explanation of stocks (as in IRES)
• How to allocate fuels input between electricity and heat ion
CHP plants
• Calculation of renewable part of electricity, taking trade into
account.
• Correct errors in the renewable table (table 5.9)
• Remove repeating text about heat pumps
• Some restructuring of the introduction part of the chapter
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Other comments
• Give better explanations certain places or rephrase some of
the text.
• Use the term ”energy products” (not energy commodities)
everywhere in the chapter.
• Emphasize, and describe annual energy balance before
quarterly or monthly balances
• Better explanations of treatment of electricity in hybrid cars.
• Consider the text on backflows / petrochemical plants
(is it necessary to explain it)
• Delete appendix C on calculation of ”useful energy”
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Comments
• Most comments are implemented;
• However, I do not recommend to include energy from heat
pumps in energy balances, due to the uncertainty in the
calculations, but it is recommended to have additional
tables for it. Furthermore, IRES doesn’t recommend it to be
included.
• Explanation of electricity used in hybrid cars
are challenging.
This text could be reviewed
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Current text on hybrid cars;
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Electricity in hybrid cars and electric motor cars: Hybrid cars have a battery and
produce their own electricity from fossil fuels. Own electricity production from
fossil fuels in the car should not be included in energy balances. Certain hybrid
cars (plug-in hybrid cars) can also be charged, in addition to that they can
produce their own electricity. Electricity charged by plug-in hybrid cars and
electric motor cars should be estimated and included as electricity consumption
in road transport in the energy balance. The figures can be estimated on basis
of mileages (for instance from the vehicle registry) and information about
electricity charged per km. driven (usually around 0,2 kWh/km). Furthermore, it
is necessary with surveys that indicate how much plugin hybrid cars are charged
vs. producing its own electricity. The surveys must also contain information on
where the cars are charged. If the cars are charged at home 30 per cent of the
time, the corresponding quantity of electricity has to be deducted from electricity
consumption in households, in order to avoid double counting of electricity.
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Some points for discussion
• Heat pumps in energy balances
• Calculation of electricity i hybrid cars
• Calculation of renewable electricity consumption
• Efficiencies used to calculate the primary energy equivalent
(hydro, nuclear, geothermal etc.) on basis of the output of
electricity and heat. Are they the same for all countries /
institutions ?
• Does the current chapter follow the earlier outlines of the
chapter?
• Other things?
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Memorandum of annotated draft outline of
chapter 5 (which was tabled at the OG meeting in
canada 2009)
• Chapter 6 Compilation of energy balances
• This chapter will provide details on good practices in
compilation of various types of energy balances focusing on
the reconciliation of data obtained from different sources and
other technical issues. Examples of energy balances
compiled by several countries will be included.
• Also, the balance formats used by UNSD, IEA and Eurostat
will be presented together with a correspondence between
them and the rationale for use of these formats.
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More detailed guidelines for chapter 5, prepared
by UNSD and the OG secretariat says the
following;
This chapter will provide practical guidance for the
compilation of energy balances. In particular, it will describe
how to use the data items presented in Chapter 6 of IRES
(and discussed in Chapter 4 of the ESCM) in the balances.
Data editing and the validation rules inherent to the energy
balances will also be addressed here.
This chapter will also discuss secondary data sources that
can be used for the compilation of balances when only
partial data items are available, as well as associated data
estimation and reconciliation methods.
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outline by UNSD / OG secretariat continues.
• A. Commodity balances
How to compile commodity balances from the data items in
Chapter 4. In the absence of some of the data items, this
section will describe secondary sources that can be used
for compiling the commodity balances
• B. Energy Balances
How to go from commodity balances to energy balances;
description of the methods for setting the value of primary
energy (physical energy content vs. partial substitution
methods), use of calorific values;
• C. Validation rules
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Thank you for your attention
Contact info: Ann Christin Bøeng.
E-mail: [email protected]
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