GEOTHERMAL RESOURCES AT LOW TEMPERATURE FOR GREENHOUSE APPLICATION IN RURAL ECONOMY

1. 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

2. 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

3. ENERGY IN GREENHOUSE AGROINDUSTRY

4. 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

5. 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

6. GEOTHERMAL ENERGY FOR AGRICULTURE

7. 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).

8. Geothermal and greenhouses areas in Italy GREENHOUSE AREA LOW GEOTHERMAL ENERGY HIGH GEOTHERMAL ENERGY

9. 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%).

11. 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

12. INTEGRATED USE OF GEOTHERMIC ENERGY AT LOW TEMPERATURE

13. Free convection pipes Fan-jet forced convection ENERGY USE IN AGRICULTURE Greenhouse heating (1) High temperature systems

14. Soil heating (burried pipes) Soft plastic sleeves on the ground Hortitherm system Low-temperature roof heating ENERGY USE IN AGRICULTURE Greenhouse heating (2) Low temperature systems

15. 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.

16. Funds and grants distributed in Italy by the Law 86/896 Source: report Altener on European insurance scheme to cover Geological Risk related to geothermal operation. Final Report, June 1997.(1EURO= 1936,27 Lit)

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

18. 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.

19. Approaches for geothermal greenhouse heating • 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. • 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).

20. 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)

21. Development of geothermal direct uses

23. ACTORS FOR IMPLEMENTING GREENHOUSE GEOTHERMAL MARKET 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).

24. ENEA ACTIVITY ON GEOTHERMAL GREENHOUSE TECHNOLOGY Scientific responsible: Carlo Alberto Campiotti

25. THANKS FOR YOUR ATTENTION CARLO ALBERTO CAMPIOTTI campiotti@casaccia.enea.it