Geothermal Energy Use in Germany at the Turn of the Millennium

Abstract

By the end of 1999 direct thermal use of geothermal energy in Germany amounted to an installed thermal power of roughly 397 MWt. Of this sum, approximately 55 MWt are generated in 27 major centralised installations. Small, decentralised earth-coupled heat pumps and groundwater heat pumps are estimated to contribute an additional 342 MWt. By the year 2002 an increase in total installed power of about 120 MWt is expected: 82 MWt from major central and 40 MWt from small, decentralised installations. This would boost direct thermal use in Germany close to an installed thermal power of 517 MWt. At present no electric power is produced from geothermal resources in Germany, whose annual final energy consumption at present amounts to about 9469 PJ. Final energy is defined as the fraction of primary energy which is supplied to the final consumer. It is less than the corresponding primary energy because of losses, mainly due to conversion and distribution. Related to one year this is equivalent to a total consumed power of approximately 300,000 MW. Almost 60% of this energy is required as heat. The total technical potential for the direct use of geothermal energy in Germany is 2125 PJ a-1, with a weighting according to the local variation in the demand for heat; this is equivalent to a maximum thermal power generation of about 67,380 MWt. This corresponds to about 22 % of the countryís annual final energy consumption, or roughly 37 % of its demand for heat. However, at present only about 6 â of the existing maximum 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 utilised to substitute fossil fuels, roughly 100 million tons less of CO2 would be released to the atmosphere annually, equivalent to about 10 % of Germanyís CO2 output in 1998.