| Abstract |
At present, 180 geothermal installations for direct use of geothermal energy are operating in Germany. The installed capacity of these plants amounts to roughly 260 (geothermal) / 650 (total, including peak load capacity etc.) MWt. The installations comprise centralised heating units (district heating), space heating in some cases combined with greenhouses, and thermal spas. Most of the plants are located in the North German Basin, the Molasse Basin in Southern Germany, or along the Upper Rhine Graben. In addition to these large-scale plants there are numerous small- and medium-size decentralised geothermal heat pump units (ground coupled heat pumps and groundwater heat pumps). Their installed capacity nearly reaches 2,600 (geothermal) / 3,500 (total, including electrical energy consumed) MWt. After a period of growth in the past decade, the number of newly installed geothermal heat pumps decreased over the last years, due to economic and regulatory shortcomings. By the end of 2013 direct thermal use of geothermal energy in Germany amounted to a total installed thermal capacity of about 2,850 (geothermal) / 4,150 (total) MWt. Organic Rankine and Kalina cycle techniques allow efficient electricity production at temperatures down to 100 °C and makes geothermal power production feasible even for countries like Germany lacking high enthalpy resources at shallow depth. In 2013 three new power plants Dürrnhaar (5.5 MWe), Kirchstockach (5.5 MWe) and Sauerlach (5 MWe) have been commissioned resulting in a total installed capacity of 27.1 MWe in Germany. Apart from funding R&D projects, the Federal Government is also creating incentives for new projects by offering a feed-in tariff for geothermal electricity under the Renewable Energy Sources Act (EEG). The amendment of the EEG with improved conditions for geothermal energy has come into effect on 1st January 2012. The subsidy for geothermal electricity has been increased to 0.25 €/kWh with additional 0.05 €/kWh for the use of petrothermal (EGS) techniques. A revision of the EEG in summer 2014, abolished the petrothermal bonus, and deteriorated the economic boundaries for selling the electricity. The Renewable Heat Act (EEWärmeG) of 2009, which has come into force in an amended version in 2011, mainly aims at the installation of renewable heat sources in buildings. The Leibniz Institute for Applied Geophysics (LIAG) is running an internet based information system on geothermal resources (Agemar et al. 2014a, b, GeotIS 2014). The system provides data of all centralised geothermal installations in Germany and information and data compilations of deep aquifers. The project aims at an improvement of quality in the planning of geothermal plants and at a minimization of exploration risks. |