Geothermal energy use in Germany--status and potential

Abstract By the end of 1995 direct thermal use of geothermal energy in Germany amounted to an installed thermal power of roughly 323 MWt. Of this sum, 38.7 MW, are generated in 22 major centralized installations. Small, decentralized earth-coupled heat pumps and groundwater heat pumps are estimated to contribute an additional 95 and 190 MW, respectively. By the year 2000 an increase in total installed geothermal power of about 144 MWt is expected: 115 MWt from major central and 29 MWt from small, decentralized installations. This would bring direct thermal use in Germany close to an installed thermal power of 467 MWt. At present no electric power is produced from geothermal resources in Germany, whose annual final energy consumption now amounts to about 9000 PJ. This is equivalent to a total consumed power of 285,000 MW. Almost 60% of this energy is required as heat. The technical potential for direct thermal use of geothermal energy in Germany is estimated to be 1622 PJ yr−1 for hydrothermal applications and 960 PJ yr−1 for earth-coupled and groundwater heat pumps; this is equivalent to a thermal power generation of 51,400 and 30,420 MW, respectively. The total, 81,820 MWt, corresponds to about 29% of the country's annual final energy consumption, or roughly 49% of its demand for heat. However, at present only about 4% of the existing technical potential for direct thermal use of geothermal energy meets the demand for heat. If the vast potential of geothermal energy for direct thermal use was utilized to substitute fossil fuels, roughly 110 million tons less of CO2 would be released to the atmosphere annually, equivalent to about 12% of Germany's CO2 output in 1994.