GeologicalSurvey of Sloveni a

1. Characteristics of geothermal potential, current utilization and its future (challenges) in SloveniaAndrejLapanje, Nina Rman, Dušan Rajver GeologicalSurvey of Slovenia RENEXPO, Budapest, 6 May2011

2. LECTURE CONTENT • GEOTHERMAL SYSTEMS IN SLOVENIA • GEOTHERMAL ENERGY POTENTIAL IN SLOVENIA • GEOTHERMAL ENERGY USE IN SLOVENIA • GEOTHERMAL ENERGY USE IN THE NE SLOVENIA • PRESENT AND FUTURE OF GEOTHERMAL UTILIZATION IN SLOVENIA

3. GEOTHERMAL SYSTEMS IN SLOVENIA • Existence is dependant on geology, while their utilization on economic conditions • Potential for geothermal heat pumps utilization is not estimated in a wider scale but utilization is applied • In Slovenia mostly low-temperature aquifers in warm spring, sedimentary basin and basement of sedimentary basin systems exists • Middle and high-temperature aquifers in sedimentary basins and the basement are only presumed to exist

4. GEOTHERMAL SYSTEMS IN SLOVENIA Various systems → different water properties → different use and problems

5. SURFACE HEAT-FLOW DENSITY (mW/m2) • Thinner solid crust in the NE Slovenia – higher than normal heat flow (>65 mW/m2)

6. EXPECTED TEMPERATURE AT 1 KM DEPTH

7. EXPECTED TEMPERATURE AT 3 KM DEPTH

8. Geothermal energy – POTENTIAL FOR ELECTRICITY • Indications on possible high temperature reservoirs in NE Slovenia → yet to be proven

9. Geothermal energy – POTENTIAL FOR ELECTRICITY • Potential high temperature reservoirs: - aquifer depth, thickness and boundaries - water yield, wellhead and reservoir pressure and temperature - water chemistry - produced energy - reinjection • Mg-6 - temperature 202°C at 3739 m - no hydraulic tests were performed • Possible deeper drilling in existent boreholes for evaluation of the geothermal potential • Nearest demonstration geothermal electricity plants: Altheim (1 MWe), Bad Blumau (0.2 MWe)

10. GEOTHERMAL UTILIZATION IN SLOVENIA • Direct use • Thermal water is in usage at 30 locations • Capacity: 66.8 MWt(in 2010) • Energy: 774.6 TJ (in 2010) • > 4400 geothermal heat pumps (GHP) - open groundwater system (W) - closed system (H and V) - groundwater temperature 4-20°C • Capacity: 49.9 MWt(May 2010) • Energy: 244 TJ (May 2010) • Total capacity in Slovenia (June 2010): 117 MWt • Total energy use in Slovenia (June 2010): 1019 TJ

11. LOCATIONS AND TYPES OF DIRECT USE IN SLOVENIA

12. EXAMPLES OF DIRECT USE IN SLOVENIA Moravske Toplice – Health resourt Murska Sobota – District heating Pirniče - Meditation Dobrovnik – Orchids greenhouse Lendava – De-icing Benedikt – Space heating

13. SHARE (%) OF GTE CAPACITY IN SLOVENIA BY FIELD (June 2010)

14. GTE DIRECT USE INSTALLED CAPACITY (June 2010)

15. GTE DIRECT USE ANNUAL ENERGY USE (June 2010)

16. GEOTHERMAL ENERGY USE IN NE SLOVENIA

17. IDENTIFIED UTILIZATION PROBLEMS IN NE SLOVENIA • Degassing of methane, CO2, H2S • Scaling • High organic matter content • Changes in chemical composition • Water-level and yields decrease, interference • Sand-clogging • Pump cavitation

18. IDENTIFIED UTILIZATION PROBLEMS IN NE SLOVENIA

19. PROJECT ADDRESSING THE GEOTHERMAL IN NE SLOVENIA http://www.t-jam.eu • Conceptual models: • Geological • Hydrogeochemical • Geothermal • Hydrogeological

20. PROJECT ADDRESSING THE GEOTHERMAL IN NE SLOVENIA http://www.t-jam.eu http://akvamarin.geo-zs.si/t-jam_boreholes/

21. PROJECT ADDRESSING THE GEOTHERMAL IN NE SLOVENIA http://akvamarin.geo-zs.si/users/ http://transenergy-eu.geologie.ac.at/

22. PRESENT AND FUTURE OF GEOTHERMAL IN SLOVENIA • Geothermal energy utilization rises, especially GHP • Strong interest in geothermal energy in the NE Slovenia • Thermal water production rises with no reinjection applied • Cascade use, operational and waste water monitoring are mostly poorly applied • Utilization problems are becoming more evident • Geothermal electricity is questionable in Slovenia • Investors wanted for inactive wells exploitation (Janežovci, Mislinjska Dobrava, Turnišče, Dobrovnik, Izola…) • Investors wanted for drilling new wells (Goriška Brda, Zasavje, Besnica, Petišovci…) • No national evidence on installed GHP • No national monitoring system for deep geothermal systems • Only rare concessions granted, no control or deadlines

23. Future challenges • Geologists & Drillers : - current exploitation: - designing unified operational and national monitoring for sustainable production of thermal water - dealing with aquifer changes: pressure drops, temperature and chemistry changes, interference, aquifer response to reinjection - developing, modeling and testing doublet systems: reinjection into sand and loose sandstone reservoirs - new research: - developing new low and high temperature geothermal sites - exploring indicated potential high temperature deep geothermal aquifers - exploring EGS potential in Slovenia - identifying potential areas for GHP’s installation, elaborating expert basis, and estimating influence of its increasing installation on hydrogeological conditions in shallow aquifers

24. Future challenges • Users & Investors: - applying technologicaloptimization at operating geothermal sites: higher efficiency of heat extraction, cascade use, prevention of scaling and degassing - installing hybrid systems and cogeneration - installing GHP’s in larger infrastructure objects according to European Energy Performance of Buildings Directive (EPBD) - implementing operational monitoring on active wells - developing new geothermal sites • Authorities: - enhancing national-wide geothermal and structural research by national and regional plans (financing & conducting research) - enhancing GHP’s and other direct use geothermal installations by subsidies and expert support - regulating new installations of water-water GHP’s - issuing research and water permits and control their implementation - designing, maintaining and interpreting national monitoring - interpreting and controlling operational monitoring

25. THANK YOU! AFP-1/95 photo: Geoprojekt