| Abstract |
In north-eastern Slovenia, the most geothermally utilized region and belonging to the geothermally anomalous Pannonian Basin, no significant progress with new deep drillings was achieved in geothermal development for direct heat use of thermal water during the last five years. The geothermal energy use in Slovenia stagnates. It does not develop. Improvements are just better utilization schemes at several localities with introduction of heat exchangers and heat pumps of bigger rated power for more economical geothermal heat use. Of three geothermal boreholes, recently drilled just before 2015 with good characteristics and depths between 1.2 and 1.52 km, only one, 1.48 km deep, is in production for greenhouse and soil heating for the tomato production since 2013 at Renkovci, while two others (for a new doublet system) at Murska Sobota are considered stranded as the Municipality preferred other energy sources for district heating operation. They all tap thermal water from the Late Miocene (Pannonian-Pontian) sand aquifer with temperatures of 44 to 77 °C. No other new direct heat user has appeared in the country, and no deep research has been done to check the probable existence of suitable deep geothermal systems to be enhanced for binary power production in this period. The installed capacity and annual energy use of 31 users amounted to 62.1 MWt and 600 TJ. Greater progress is achieved in shallow geothermal energy use, where the number of smaller GSHP units of typically 11 to 12 kW is ca 12,074 with 147.4 MWt capacity and 737 TJ/yr energy use (Dec. 2019). The number of bigger GSHP systems with heat pumps of rated power over 20 kW is also in constant increase during the last 5 years, resulting in 53.5 MWt and 272.2 TJ/yr, with some 656 systems accounted for, however detailed operational data for the latter are difficult to get, especially for buildings in private sector (factories, touristic facilities, etc) since there is no regulation in place. The total complete numbers are 262.9 MWt and 1609.5 TJ/yr. It is expected the trend of energetic renovation of older buildings (including blocks of flats in the cities) will continue more intensively in future, also with installation of the GSHP units, as one of the obligations to reach the renewable energy targets set by the EU directives. |