GEOTHERMAL
RESOURCES
AT
LOW
TEMPERATURE
FOR
GREENHOUSE
APPLICATION IN RURAL ECONOMY
Carlo Alberto Campiotti, Francesca Dondi
ENEA Casaccia, dpt. BAS
Email: campiotti@casaccia.enea.it
22 november, 2007
ENERGY FOR GREENHOUSES
Agriculture is directly responsible for 3-5% of the total fuel
used in European western countries, some 40% of that
being for heating. Of this thermal energy consumption, an
average of 60% is spent for greenhouse heating, relatively
more in the north and less in the south.
So, we end up with greenhouse heating making up about
2% of EU western countries total energy consumption.
MEDIUM TECHNOLOGY
HIGH TECHNOLOGY
LOW TECHNOLOGY
ENERGY IN GREENHOUSE AGROINDUSTRY
EUROPEAN AREA
Netherlands – Germany
North of Italy
Middle of Italy
Israel
South of Italy
(ENERGY) CAPACITY
250 W/m2
150-200 W/m2
100-150 W/m2
80-120 W/m2
30-50 W/m2
SOUTH EUROPE
5 - 6 kg
of oil diesel/year/m2
NORTH EUROPE
60 - 80 kg
of oil diesel/year/m2
Emission: 0.5 kg of CO2 per Kg of oil diesel
GREENHOUSE ENERGY BUDGET
2 – 3 kWh/m2/day (14-10 °C)
North of Europe
0.5 – 1 kWh/m2/day (12-10 °C)
South of Europe
WORLD PROTECTED CULTIVATION
• WESTERN EUROPE: 140,000 Ha
Spain, Italy, France, Netherlands
• AFRICA: 27,000 Ha
Morocco, Tunisia, Algeria
• MIDDLE EAST: 28,000 Ha
Turkey, Israel, Jordan
• AMERICA (North and South): 22,350 Ha
USA, Colombia, Ecuador, Argentina
• ASIA: 450,000 Ha
China, Japan, Corea
Source: Jouet, 2001
CEE - PROTECTED CULTIVATION
GLASSHOUSES: 12,400 Ha
GREENHOUSES (plastic - tunnels): 77,724 Ha
Total Protected Cultivation: 90,124 Ha
GEOTHERMAL GREENHOUSES ** : 1067 Ha
* Vegetable and flori-ornamental cultures.
** Surface included in the glasshouses.
Source: Campiotti, 2007
GEOTHERMAL ENERGY FOR AGRICULTURE
Geothermal Direct Uses (Sources : IGA)
France and Italy as the leading countries. Uses consist chiefly of district heating (Iceland
and France), agricultural uses and balneology/therapy (Italy, Hungary, Turkey) and
geothermal heat pumps GHP (Switzerland, Germany and Sweden).
COUNTRIES
Installed
MWt
Production
GWh/a
China
2282
10531
Japan
1167
7482
USA
3766
5640
Iceland
1469
5603
Turkey
820
4377
New Zealand
308
1967
Georgia
250
1752
Russia
308
1707
France
326
1360
Sweden
377
1147
Hungary
473
1135
Mexico
164
1089
Italy
326
1048
Romania
152
797
Switzerland
547
663
Geothermal and greenhouses areas in Italy
GREENHOUSE AREA
LOW GEOTHERMAL ENERGY
HIGH GEOTHERMAL ENERGY
GEOTHERMAL SPRINGS IN ITALY
An inventory of Italy’s thermal waters lists 485 thermal points. These consist of
347 springs and 138 wells (less than 1000 m depth) producing water ranging from
20°C to 39°C (71%), 40°C to 59°C (21%) and <60°C (8%).
Geothermal spring resources and greenhouses in Italy *
Geothermal spring points
Greenhouse industry (he)
Geothermal applications (he)
25% in Tuscany
< 1,000
28
16% in Latium
< 3000
16
13% in Campania
> 5,000
-
12% in Sicily
> 10,000
-
9% in Sardinia
< 3000
-
8% in Veneto
< 200
3
17% in the other Italian
regions
*
-
the total greenhouse surface in Italy has been estimated to be not less than 30,000 Ha,
20% of which are fitted with heating installations.
Geothermal greenhouses in Italy
Location
Galzignano
(Padua)
No. of wells
Depth (m)
Flow-rate
Type
of resource
Greenhouse
area (he)
Capacity
(MWt)
Energy saving
(OET/year)
2
300
78
P
2.9
2.9
1300
2000
S
23
85
30000
B
Amiata (Siena)
Integrated
uses
Castelnuovo (Pisa)
700-1000
31
S
0.68
1.0
300
D
Lago (Pisa)
700-1000
2.5
S
1.3
1.6
500
SH
SH+AQ
Pomarance (Pisa)
1
1300
35
S
0.5
0.9
300
Radicondoli
(Siena)
1
900
250
S
2.4
9
3200
Canino (Viterbo)
1
35
A
0.17
0.5
100
Pantani (Rome)
4
800
P
16
24
20000
Sardara (Cagliari)
1
A
(0.5)
(1.5)
(200)
Pozzuolo del Friuli
(Udine)
1
A
1
0.5
60
48.45
126.9
55,960
420
400
35
TOTAL
1= P: pumping; S: steam or consensate waste from geothermal power-plants; A: artesian.
2=B: baths; D: drying; SH: space-heating; AQ: aquaculture.
From:Campiotti C., Picciurro G., Popovski K., Dickson M.H., Fanelli M. (1990).
AQ
B
Geothermal water at low-temperature is compatible with a wide range of
geothermal greenhouses (forced-air distribution employing water-to-air heat
exchangers, hot water radiator systems as plastic pipes and finned tubes,
liquid-based radiant heat in the floor, bench-mounted-liquid based radiant
heat, direct soil heating) with energy capacity ranging from 20 to 70 W/m2
INTEGRATED USE OF GEOTHERMIC ENERGY AT LOW TEMPERATURE
ENERGY USE IN AGRICULTURE
Greenhouse heating (1)
High temperature systems
Slide Title
Slide Title
Free convection pipes
Fan-jet forced convection
ENERGY USE IN AGRICULTURE
Greenhouse heating (2)
Low temperature systems
Soil heating
(burried pipes)
Title Slide
30- 50 cm
Slide Title
Title Slide
Soft plastic
sleeves on the
ground
15- 40 cm
Slide Title
Slide Title
Hortitherm
system
Lowtemperature
roof heating
GEOTHERMAL ENERGY AND GREENHOUSE HEATING
Nowadays, the European energy demand is in the range of 1,292 MtOE/year,
of which about 2% as energy demand for greenhouse agriculture (26
MtOE/year).
If we focus on the EU target of 12% as renewable supply, we would have
26*0.12 = 3.12 MtOE/year as potential energy renewable supply target according
to the project energy objectives.
If we look at the potentially enormous quantity of geothermal heat (10-15 million
tOE), and according to the geothermal energy used for the greenhouse heating
industry which is only 0,1 million tOE/year, which represents 0.38%
(0.1/26*100 = 0.38%) of the total greenhouse energy demand.
Although the numerous factors, e.g. technical problems of transportation to users,
the imbalance between continuous supply and periodic utilization the availability
of local demands for the usually huge heat sources, etc., which limit its
applicability, the geothermal greenhouse supply is very low.
The geothermal greenhouse heating could potentially provide of 46%
(12/26*100 = 46%) of the total energy greenhouse demand in the European
greenhouse industry.
Funds and grants distributed in Italy by the Law 86/896
YEAR
AVAILABLE FUNDS (x1000)
GRANTS DISTRIBUTED
1987
12,300
7,824
1988
17,800
6,398
1989
10,056,15,050
2,424
1990
5,000
1,335
1991
5,000
-
1992
5,000
-
1993
5,000
-
1994
5,000
70
1995
3,800
-
1996
3,800
-
TOTAL
82,806 (40 Million Eur)
18,051
Source: report Altener on European insurance scheme to cover Geological Risk
related to geothermal operation. Final Report, June 1997.(1EURO= 1936,27 Lit)
National support as Research, development
and demonstrative plants for RES in Italy
Years 1993-2001 (MEur 2002)
ENERGY SOURCE
2001
2000
1999
1998
1997
1996
1995
1994
1993
BIOMASS
6.9
8.8
5.6
8.6
7.6
10
9.9
6.7
7.6
GEOTHERMIC
0
0
0
0
0
0
0
0
0
HYDROELECTRIC
0
0
0
0
0
0
0
0
0
BIOGAS
0
0
0
0
0
0
0
0
0
PHOTOVOLTAIC AND
THERMAL SOLAR
17
18.7
19
19.8
23
19.3
22.5
23.7
16.8
EOLIC
1.5
2.1
1.4
5.9
6.2
10.7
10.3
1
3.3
TOTAL
25.4
29.6
26
34.3
36.8
40
42.7
31.4
27.7
Source: IEFE – Bocconi University
Factors which determine the greenhouse
geothermal economy
The distance between the resource and the plant greenhouse must be as small as possible to
reduce the costs of pipelines and avoid lost of temperature.
The short-term applications makes geothermal energy uneconomical because to achieve real benefits
it must be used over a long period of the year and should be addressed to cover base heat
requirement of the greenhouse energy load while peek heat demand should be meet with
conventional heat technologies.
The payback period for covering investment costs is strongly influenced by the heating system
solution which, however, depends on the greenhouse dimension and technology level and the local
climate.
The timing, the agro-techniques and the biological characteristics of the crops (vegetable or
flower) are of primary importance to achieve economical benefits with geothermal greenhouse.
To achieve appreciable savings as well as an optimal utilization factor, it should be adopted an
integrated scheme and/or a cascade heat system to simplify and to optimise the heat use from
geothermal sources.
The application of heat pumps for extracting energy from very low temperature resources
(<40°C) and the development of appropriate managing options to integrate more energy users in order
to decrease the price of used heat.
Approaches for geothermal greenhouse heating
1) simple installations (10 to 40 W/m2), made of cheap plastic materials
(polyethylene or polybutylene) with installations directly connected to
the heat resource which has the main scope to increase indoor
temperature during short, cold periods.
2) sophisticated solutions (50 to 70 W/m2), that can cover intensive
production requirements in specialized greenhouses adapted for high
quality plant productions even for geographical areas characterized
by severe climatic conditions.
3) in-between solutions (30 to 70 W/m2), that comply with costs,
grower’s experience and market.
As general figure, it should be kept in mind that for the mild
climates (which characterize the Mediterranean countries) a
practical criteria is to supply 150-200 kcal/h per square meter of
covered surface (0.2 kW/m2).
ELECTRICITY GENERATION
INSTALLATION AND PLANT COST : 1000 – 3000 €/kWe
PRODUCTION COST : 25 - 60 €/MWhe
DIRECT USES
INSTALLATION AND PLANT COST : 200 - 700 €/kWt
PRODUCTION COST : 3 -15 €/MWt
UTILIZING FACTOR
0.8 (GEOTHERMIC ENERGY) - 0.20 – 0.35 (EOLIC – SOLAR)
Development of geothermal direct uses
White Paper
Current trend
Estimated carbon dioxide emission reduction
from renewable energy in Europe
TYPE OF ENERGY
ADDITIONAL CAPACITY
1997-2010
CO2 REDUCTION
Million tonnes/year IN 2010
Wind
36 GW
72
Hydro
13 GW
48
Photovoltaics
3 GWp
3
Biomass
90 Mtoe
255
Geothermal (+
heat pumps)
2.5 GW
5
Solar collectors
94 Mio m2
19
TOTAL for EU market
Source: Blue Book on Geothermal Resources
402
ACTORS FOR IMPLEMENTING GREENHOUSE
GEOTHERMAL MARKET
Research, institutes, experts and scientists, since they have to provide knowhow, sustainable technologies and proposals for Municipalities and public actors of
geothermal regions to support the use of local renewable energies for greenhouse
industry.
Farming greenhouse communities, which have to be convinced of the opportunity
of developing available geothermal resources as potential greenhouse districts.
Regional and local Authorities, since they must put in operation legislative
measures (proposals by experts) for supporting programmes for financing help,
grants and subsidies aimed at favouring RES implementation.
Supporters (trade unions, environmentalist organizations, the general public,
the professional networks,banks etc.), since they should encourage end-users with
information on the profitability of geothermal energy in the greenhouse sector.
Press and media, because they are particularly important to establish
communication channels, general awareness and sensibility between key-actors
(stakeholders, decision-makers, supporters, users).
ENEA ACTIVITY ON GEOTHERMAL GREENHOUSE TECHNOLOGY
 EC-Thermie contract on the "Development of a Model for Using Geothermic Energy as
heat for greenhouses in the Mediterranean climatic area". Thermie 1991-94, Contract
No.GE/41/92/IT/HE.
 EC-Thermie contract on "Utilization of Geothermal Water Effluents in Greenhouses for
Special Crops in Windy and Humid Areas". Program Thermie 1994-98, Contract
No.GE/359/94/PO/IT.
 Coordinator of ALTENER project AL/2000/143, “Promotion and dissemination policy on
local natural resource use (geothermal and solar) for agricultural applications in rural areas
of CEC and EU”, 2000-2002.
 Project N. 012066-VI FP 2006. Priority INCO-2002-C.1.3. Renewable Energy Coordinated Development in the Western Balkan Region. Acronym: RECOVER.
Scientific responsible: Carlo Alberto Campiotti
THANKS FOR YOUR ATTENTION
CARLO ALBERTO CAMPIOTTI
campiotti@casaccia.enea.it