1. Geothermal energy GEOTHERMAL ENERGY Fausto Batini Enel – International Rome – Italy fausto.batini@enel.it Rome, 2006 5th July

2. Geothermal energy Contents 1° PART 1.introduction 2.Geothermal energy basic concepts Heat sources Geothermal systems 3.The geothermal industry worldwide Electric energy generation Direct use application 2° PART 1. Resource assessment and project development Ranking of geothermal prospects Project development Operation and maintanamce 2.Drivers & barriers for the geothermal energy growth Technological challenges Economic and environmental sustainability 3.Conclusions

3. Geothermal energy Contents 1° PART 1.introduction 2.Geothermal energy basic concepts Heat sources Geothermal systems 3.The geothermal industry worldwide Electric energy generation Direct use application 2° PART 4. Resource assessment and project development Ranking of geothermal prospects Project development Operation and maintanamce 5.Drivers & barriers for the geothermal energy growth Technological challenges Economic and environmental sustainability 6.Conclusions

4. Geothermal energy The principal electricity operator in Italy with the leading position in the generation, transmission*, distribution and sale of electricity Strong presence in the gas market One of the world largest operators in the energy sector Enel market capitalization Source: Bloomberg * Enel owns 36,14% of the share capital of Terna and has already signed an agreement for the sale of up to 30% of the company

5. Geothermal energy Enel in the world Europe America 53.161 MW, 750 power plants, 1.000.000 km grid, over 34 million customers America 1.592 MW Thermal 671 MW Hydroelectric 600,000 customers ! 50% of EUFER: 294 MW Wind 89 MW Hydroelectric 62 MW Cogeneration SPAIN ROMANIA 51% of Dobrogea 51% of Banat 1.4 million customers RUSSIA North Western thermal power plant management contract BULGARIA 67% of Maritza East III: 732 MW Thermal SLOVACCHIA 66% of Slovenske Elektrarne 6.850 MW ITALIA 30 million customers (power) 2 million customers (gas) 42.000 MW 286 MW Hydroelectric 67 MW Wind 21 MW Biomass and Biogas 293 MW Hydroelectric 20 MW Wind 115 MW Geo (12,7% of LaGeo) Over 19.000 MW of renewable energy

6. Geothermal energy Contents 1° PART 1.introduction 2.Geothermal energy basic concepts Heat sources Geothermal systems 3.The geothermal industry worldwide Electric energy generation Direct use application 2° PART 1. Resource assessment and project development Ranking of geothermal prospects Project development Operation and maintanamce 2.Drivers & barriers for the geothermal energy growth Technological challenges Economic and environmental sustainability 3.Conclusions

7. Geothermal energy Temperature gradient in the earth is 33°C/km (In the geothermal areas > 100 °C/km) A mean heat flux at the earth's surface is around 16 kW t / km 2 (In the geothermal areas > 100 kW t / km2 ) 42.000.000 MW t dissipated to the atmosphere and space Geothermal heat source Geothermal energy is, literally, the heat contained within the Earth that generates geological phenomena on a planetary scale. Only a fraction of this energy can be recovered and exploited by man.

8. Geothermal energy The thermal engine in the Earth Immense volumes of deep hotter rocks, less dense and lighter than the surrounding material, rise with convective movements towards the surface

9. Geothermal energy Geothermal areas worldwide The heat flux tends to be strongest along tectonic plate boundaries where volcanic activity transports high temperature material to near the surface. However, even in parts of the world far from plate boundaries, there can still exist areas of higher than average natural heat flow.

10. Geothermal energy Geothermal system Heat source Depth 5-10 km T > 600- 700 ° C Meteoric water Hot fluid Production wells Caprock Thickness 500 – 1500 m Impervious rocks Utilization of geothermal energy has been limited to areas in which geological conditions permit a carrier (water in the liquid phase or steam) to 'transfer' the heat from deep hot zones to or near the surface, thus giving rise to geothermal system Reservoir Porous – fractured rocks Tickness 500 – 1500 m T = 150 – 300 °C Reinjection well Power plant Steam gathering system Drilling rig

11. Geothermal energy Geothermal system

12. Geothermal energy Geothermal systems

13. Geothermal energy Electric energy generation This is the most common type of geothermal power unit. NAMEPLATE CAPACITY : 5 - 60 MW NAMEPLATE CAPACITY : 2 - 10 MW

14. Geothermal energy Direct use of geothermal heat

15. Geothermal energy HDR Project at Soultz: the Pilot Plant concept Heat mining Develop advanced technology to use the huge thermal energy amount contained in the earth crust

16. Geothermal energy Contents 1° PART 1.introduction 2.Geothermal energy basic concepts Heat sources Geothermal systems 3.The geothermal industry worldwide Electric energy generation Direct use application 2° PART 1. Resource assessment and project development Ranking of geothermal prospects Project development Operation and maintanamce 2.Drivers & barriers for the geothermal energy growth Technological challenges Economic and environmental sustainability 3.Conclusions

17. Geothermal energy Once upon a time at the underworld watchdog site... Larderello (Italy)… The dawn of geothermal industry … in 1817 a small group of entrepreneurs formed the first geothermal firm starting the extraction of boric acid by evaporation of the waters of the many geothermal lagoons present in the Larderello region.

18. Geothermal energy… … and to measure the power of the steam … in 1827 the first approach to explore the hell … The dawn of geothermal industry

19. Geothermal energy… The dawn of geothermal industry The first commercial electric power plant Larderello 1 ( 1916 ) 3x3000kW (indirect cycle) In 1904 the first experiment of electric energy generation

20. Geothermal energy Geothermal highlights in Italy Radicondoli - Travale Since 1950 Exploited area 30 km 2 steam dominated reservoir efficient capacity:160 MW Amiata since 1954 exploited area 50 km 2 Water dominated system efficiente capacity :88 MW Larderello since 1913 exploited area 250 km 2 steam dominated reservoir efficient capacity:463MW Roma Florence Year 2005 Efficient capacity (MW) 711 Net generation (GWh) 5.036 Heat distributed (Tcal ) 235 CO2 avoided (Mt) 3,4 TEP saved (MTEP) 1,13 Same geothermal system at depth over 3000 extending about 400 km 2

21. Geothermal energy Geothermal exploration & production process RESOURCE EXPLORATION & ASSESSMENT DRILLING ENGINEERING & CONSTRUCTION OPERATION & MAINTANANCE

22. Geothermal energy … to select the most promising prospect and to predict the drilling targets An interdisciplinary integrated approach is applied to build an accurate subsurface geological model of the geothermal system… Geological & structural model Exploration & resource assessment

23. Geothermal energy Drilling Vertical and directional wells are drilled from the same pad at depth of 1000 – 4500 m Montieri 1 well Steam production over 240 tonnes/h of steam

24. Geothermal energy Design & construction of the power system Power plants 20 MW each one Steam pipeline (lenght range :1-10 km)

25. Geothermal energy Reduction of gas emission AMIS (process for H2S and Hg removal) Abatement Hg>90% H 2 S70-80% Environmental sustainability Architectural solutions to minimize the visual impact

26. Geothermal energy Integrated management of geothermal resources for production optimization Field and power plant O & M Reinjection well Production well Electric power plant Steam gathering system Steam flow Water Cooling towers

27. Geothermal energy 31 Units in operation Range 6.5 MW - 60 MW 508 wells 408 km steam&water pipelines Enel’s geothermal assets in Italy All the units are remote controlled 711 MW operating capacity

28. Geothermal energy Geo-heat supply in Italy DISTRICT HEATING & GREEN HOUSES

29. Geothermal energy Fonte: IGA 2005 Enel geothermal portfolio – Ytd 2005 1930 2564 953 838 711 535 435 202 163 121 151 79 77 3328 20 16 20 0 500 1000 1500 2000 PHILIPPINES USA MEXICO INDONESIA ITALY JAPAN NEW ZEALAND ICELAND COSTA RICA KENYA El SALVADOR RUSSIA NICARAGUA GUATEMALA CHINA PORTUGAL TURKEY Others MW (installed) 3000 2500 The total installed capacity is 8,933 MW 8,000 MW running and supplying 56,786 GWh an increase of 12% and 15% respectively with respect to year 2000 Enel 100% 12.5%

30. Geothermal energy Geothermal installed capacity 2/3 of the total installed capacity are for dry steam and single flash units Binary units are increasing, but with a lower value of capacity per unit. 29% 37% 25% 8% 1% Dry Steam Single Flash Double Flash Binary Back Pressure Fonte: IGA 2005 About 8,000 MW in operation and supplying 56,786 GWh

31. Geothermal energy Energy saving & pollution avoided Electric use Energy saving (*) of fuel oil per year 96,6 million barrels or 14, 5 millions tonnes Carbon pollution avoided (millions tonnes year) 3 (natural gas) or 13 (oil) or 15 (coal) Total energy saving of fuel oil per year over 220 million barrels Total carbon pollution avoided per year over 39 (oil) million tonnes (*) generating electricity with 0,35 efficiency factor Direct uses Energy saving (*) of fuel oil per year 123,4 million barrels or 18,5 millions tonnes Carbon pollution avoided (millions tonnes year) 4 (natural gas) or 16 (oil) or 18 (coal)

32. Geothermal energy World geothermal potential … up to 72.500 MW exploitable with existing technologies while future technologies will allow the exploitation of up to 140.000 MW … Source: World Bank

33. Geothermal energy Geothermal energy worldwide development Indonesia (838 MW) Filippine (1838 MW) New Zealand (403 MW) Russia (79 MW) Canada Usa (1935 MW) Cina (19 MW) France - Guadalupe (15 MW) Portugal (13 MW) Italy (711 MW) Kenia (129 MW) Ethiopia (7,3 MW) Cile Bolivia Perù Argentina Turchia (18 MW) Iran Nicaragua (38 MW) El Salvador (119 MW) Costa Rica (163 MW) Guatemala (29 MW) Areas with high potential ( MW in operation) Japan (530MW) Iceland (202 MW) Source : Bertani WGC 2005 Mexico (953 MW) 8900 MW in operation forecasted to year 2010

34. Geothermal energy Exploration program 2004-2008 3D seismic 11 wells at depth of 3500-4500 68 € millions investment 100 MW additional in the next 5 years Enel’s new development in Italy

35. Geothermal energy Cile Partenership with ENAP ENG s.a & GDN s.a. 4 project under exploration Apacheta El Tatio – La torta Calabozo Chillan Enel’s worldwide development Berlin Ahuachapan Partenership with LaGeo 119 MW in operation 55 MW under construction El Salvador Partenership with LaGeo GEONICA s.a. 2 project under exploration Nicaragua Chiltepe Hoyo Mt.Galan North America projects under evaluation Far East Market opportunity under evaluation

36. Geothermal energy Contents 1° PART 1.introduction 2.Geothermal energy basic concepts Heat sources Geothermal systems 3.The geothermal industry worldwide Electric energy generation Direct use application 2° PART 1. Resource assessment and project development Ranking of geothermal prospects Project development Operation and maintanamce 2.Drivers & barriers for the geothermal energy growth Technological challenges Economic and environmental sustainability 3.Conclusions

37. Geothermal energy Thanks for your attention For any further information please contact me at the following e-mail address: fausto.batini@enel.it