Characteristics of geothermal potential, current utilization and its future (challenges) in Slovenia

Andrej Lapanje, Nina Rman, Dušan Rajver Geological Survey of Slovenia RENEXPO, Budapest, 6 May 2011

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

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

GEOTHERMAL SYSTEMS IN SLOVENIA

Various systems → and problems different water properties → different use

SURFACE HEAT-FLOW DENSITY (mW/m 2 )

Thinner solid crust in the NE Slovenia – higher than normal heat flow (>65 mW/m2)

EXPECTED TEMPERATURE AT 1 KM DEPTH

EXPECTED TEMPERATURE AT 3 KM DEPTH

Geothermal energy – POTENTIAL FOR ELECTRICITY

 Indications on possible high temperature reservoirs in NE Slovenia → yet to be proven

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 MW e ), Bad Blumau (0.2 MW e )

GEOTHERMAL UTILIZATION IN SLOVENIA



Direct use

   Thermal water is in usage at 30 locations Capacity: 66.8 MW t

(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 MW t

(May 2010)

Energy: 244 TJ (May 2010)   Total capacity in Slovenia (June 2010): 117 MW

t

Total energy use in Slovenia (June 2010): 1019 TJ

LOCATIONS AND TYPES OF DIRECT USE IN SLOVENIA

EXAMPLES OF DIRECT USE IN SLOVENIA

Moravske Toplice – Health resourt Dobrovnik – Orchids greenhouse Pirniče - Meditation Murska Sobota – District heating Lendava – De-icing Benedikt – Space heating

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

GTE DIRECT USE INSTALLED CAPACITY (June 2010)

GTE DIRECT USE ANNUAL ENERGY USE (June 2010)

GEOTHERMAL ENERGY USE IN NE SLOVENIA

IDENTIFIED UTILIZATION PROBLEMS IN NE SLOVENIA

       Degassing of methane, CO 2 , H 2 S Scaling High organic matter content Changes in chemical composition Water-level and yields decrease, interference Sand-clogging Pump cavitation

IDENTIFIED UTILIZATION PROBLEMS IN NE SLOVENIA

PROJECT ADDRESSING THE GEOTHERMAL IN NE SLOVENIA

http://www.t-jam.eu

Conceptual models: • Geological • Hydrogeochemical • Geothermal •Hydrogeological

PROJECT ADDRESSING THE GEOTHERMAL IN NE SLOVENIA

http://akvamarin.geo-zs.si/t-jam_boreholes/ http://www.t-jam.eu

PROJECT ADDRESSING THE GEOTHERMAL IN NE SLOVENIA

http://transenergy-eu.geologie.ac.at/ http://akvamarin.geo-zs.si/users/

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

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

Future challenges



Users & Investors:

- applying technological optimization 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

THANK YOU

!

AFP-1/95 photo: Geoprojekt