GEOTHERMAL RESOURCES AT LOW TEMPERATURE FOR GREENHOUSE APPLICATION IN RURAL ECONOMY

Carlo Alberto Campiotti, Francesca DondiENEA Casaccia, dpt. BAS

Email: campiotti@casaccia.enea.it22 november, 2007

ENERGY FOR GREENHOUSESAgriculture 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

EUROPEAN AREANetherlands – Germany

North of ItalyMiddle of Italy

IsraelSouth of Italy

(ENERGY) CAPACITY250 W/m2

150-200 W/m2

100-150 W/m2

80-120 W/m2

30-50 W/m2

ENERGY IN GREENHOUSE AGROINDUSTRY

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

SOUTH EUROPE NORTH EUROPE

5 - 6 kg of oil diesel/year/m2

60 - 80 kg of oil diesel/year/m2

Emission: 0.5 kg of CO2 per Kg of oil diesel

WORLD PROTECTED CULTIVATION

• WESTERN EUROPE: 140,000 HaSpain, Italy, France, Netherlands

• AFRICA: 27,000 HaMorocco, Tunisia, Algeria

• MIDDLE EAST: 28,000 HaTurkey, Israel, Jordan

• AMERICA (North and South): 22,350 HaUSA, Colombia, Ecuador, Argentina

• ASIA: 450,000 HaChina, Japan, Corea

Source: Jouet, 2001

CEE - PROTECTED CULTIVATION

GLASSHOUSES: 12,400 Ha

GREENHOUSES (plastic - tunnels): 77,724 Ha

Source: Campiotti, 2007

Total Protected Cultivation: 90,124 Ha

* Vegetable and flori-ornamental cultures.** Surface included in the glasshouses.

GEOTHERMAL GREENHOUSES ** : 1067 Ha

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 InstalledMWt

ProductionGWh/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

LOW GEOTHERMAL ENERGY

HIGH GEOTHERMAL ENERGY

GREENHOUSE AREA

Geothermal and greenhouses areas in Italy

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 SPRINGS IN ITALYAn 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 greenhouses in ItalyLocation No. of wells Depth (m) Flow-rate Type

of resourceGreenhouse

area (he)Capacity

(MWt)Energy saving

(OET/year)Integrated

uses

Galzignano (Padua)

2 300 78 P 2.9 2.9 1300

Amiata (Siena) 2000 S 23 85 30000 B

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

Pomarance (Pisa) 1 1300 35 S 0.5 0.9 300 SH+AQ

Radicondoli (Siena)

1 900 250 S 2.4 9 3200

Canino (Viterbo) 1 35 A 0.17 0.5 100 AQ

Pantani (Rome) 4 420 800 P 16 24 20000

Sardara (Cagliari) 1 A (0.5) (1.5) (200) B

Pozzuolo del Friuli (Udine)

1 400 35 A 1 0.5 60

TOTAL 48.45 126.9 55,9601= 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).

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

Slide Title Slide Title

Free convection pipes Fan-jet forced convection

ENERGY USE IN AGRICULTUREGreenhouse heating (1)

High temperature systems

ENERGY USE IN AGRICULTUREGreenhouse heating (2)

Low temperature systems

Title Slide

30-50 cm

15-40 cm

Slide Title

Title Slide

Slide Title Slide Title

Soil heating (burried pipes)

Hortitherm system

Soft plastic sleeves on the ground

Low-temperature 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.

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)

Funds and grants distributed in Italy by the Law 86/896

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 0HYDROELECTRIC 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

National support as Research, development and demonstrative plants for RES in Italy

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.

Factors which determine the greenhouse geothermal economy

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).

Approaches for geothermal greenhouse heating

DIRECT USESINSTALLATION AND PLANT COST : 200 - 700 €/kWt

PRODUCTION COST : 3 -15 €/MWtUTILIZING FACTOR

0.8 (GEOTHERMIC ENERGY) - 0.20 – 0.35 (EOLIC – SOLAR)

ELECTRICITY GENERATIONINSTALLATION AND PLANT COST : 1000 – 3000 €/kWe

PRODUCTION COST : 25 - 60 €/MWhe

W hite Paper

Current trend

Development of geothermal direct uses

Estimated carbon dioxide emission reduction from renewable energy in Europe

TYPE OF ENERGY ADDITIONAL CAPACITY1997-2010

CO2 REDUCTIONMillion 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 402

Source: Blue Book on Geothermal Resources

Research, institutes, experts and scientists, since they have to provide know-how, 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).

ACTORS FOR IMPLEMENTING GREENHOUSE GEOTHERMAL MARKET

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 Co-ordinated Development in the Western Balkan Region. Acronym: RECOVER.

ENEA ACTIVITY ON GEOTHERMAL GREENHOUSE TECHNOLOGY

Scientific responsible: Carlo Alberto Campiotti

THANKS FOR YOUR ATTENTION

CARLO ALBERTO CAMPIOTTI

campiotti@casaccia.enea.it