1. State-of-the-art of thermal water utilization in the TRANSENERGY region: current state, potentials and challenges Nina Rman 1 Nóra Gál 2, Daniel Marcin 3, Katarína Benková 3, Julia Weilbold 4, Gerhard Schubert 4, Tadej Fuks 1, Dušan Rajver 1, Andrej Lapanje 1, Annamária Nádor 2 1 Geological Survey of Slovenia 2 Geological and Geophysical Institute of Hungary 3 State geological Institute of Dionýz Štúr, Slovakia 4 Geological Survey of Austria Vienna, 24.6.2013

2. Aim of this overview geothermal energy utilization in the project area (year 2011) recognition of possible transboundary aquifers impact of exploitation on regional hydrogeological conditions potential for increased exploitation challenges of sustainable geothermal energy utilization WhoWhatWhere How much How What for

3. Geothermal energy resource Energy (Use) - Mining Act - Environment (Protection) - Water Act - ENERGETIC USE THERMAL WATER USE Aquaculture Technological and agricultural water Bathing and balneology Energetic use (no reinjection) Enhanced geothermal systems Geothermal doublet Geothermal heat pumps YES reinjection NO reinjection

4. (http://pubs.usgs.gov) DRAWDOWN What is so special about regional and transboundary water resouces?

5. Thermal water users T wellhead > 20°C CountryUsersWells Slovenia2035 Slovakia4459 Austria2048 Hungary129259 Total213401

6. Maximum wellhead temperature T wellhead (°C)

7. Thermal water utilization Foto: S.M., K.M., T.F. Bathing and balneologyHeating

8. Thermal water utilization P = 180 kW e net T = 110°C Q = 20 l/s M = 18 g/l

9. Exploited geothermal aquifers 11 different aquifers 0.5 to 2 km depth Q = 20-30 l/s lots of CO 2 → carbonates scaling → inhibitors Q = 5-10 l/s lots of H 2 S, CO 2 → carbonates scaling → inhibitors Q = 10-35 l/s high abstraction → pump failures due to sand clogghing

10. Monitoring of geothermal wells  Groundwater level (m)  Momentary yield (l/s)  Cumulative quantity (m 3 )  Water temperature (°C)  Chemical monitoring  Identify anomalous changes  Sustainable management  Benchmarking indicators Groundwater level monitoring

11. Thermal water production

12. Exploitation characteristics

13. Waste thermal water management sewage

14. Future geothermal development Technical potential 65 inactive users 94 inactive wells +7 mio m 3 annually: Upper Miocene clastic rocks: +2.8 million m 3 MZ carbonates: +1.7 million m 3 Others: app. + 2.8 million m 3

15. Future geothermal development Hydrogeological potential regional and transboundary aquifers → interferences → numerical models

16. Legislative potential Applications for or granted water concessions (AT, SI, SK): +30 mio m 3 annually Heat extraction: reinjection with doublets Management of resources: benchmarking Future geothermal development

17. Conclusions  Utilization status in 2011 : 148 users with 307 active wells  Low temperature resources: direct use and 1 binary electricity power plant  2 most favourable geothermal aquifers: MZ carbonates & Upper Miocene sand  Indications of overexploitation  Cascade use: improves thermal efficiency and reduces water demand  Inactive geothermal wells  Low and intermediate temperature potential for new drillings  Limited hydrogeological potential can be expanded by reinjection Monitoring system: comparable and systematic, public data  Sustainable development: pilot models, benchmarking and strategy paper

18. http://transenergy-eu.geologie.ac.at/ http://akvamarin.geo-zs.si/users Wellbore database Geological maps Utilization maps Geothermal maps Combination of layers !!! Scale !!!! Thermal water temperature and surface heat flow density Most tapped geothermal aquifers and extent of the Upper Miocene sand Temperature at 1000 m and thermal water users Interactive webmaps and database of users