Geothermal Energy Use, Country Update for Germany

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 336.6 MWt (geothermal share) and 720.1 MWt (total, including peak load capacity, etc.) with a heat production of 1,099.0 GWht (geothermal) and 1,259.9 GWht (total), respectively. 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 Molasse Basin in Southern Germany, in the North German Basin, or along the Upper Rhine Graben. Data of all centralised geothermal installations in Germany and statistics on their contribution to the renewable heat and power supply can be retrieved from the open access Geothermal Information System GeotIS, which is operated by the Leibniz Institute for Applied Geophysics (LIAG). Besides data on geothermal energy use, the system provides information and data compilations on deep hydrothermal aquifers as well as potential petrothermal resources. The GeotIS project aims at an improvement of quality in the planning of geothermal projects and at the minimisation of exploration risks.
In addition to installations using “deep” geothermal energy numerous small- and medium-sized decentralised geothermal heat pump units are in use for heating and cooling of individual houses and office buildings (ground coupled heat pumps and groundwater heat pumps). Their total installed capacity (including electrical energy consumed) reached 3,900 MWt in 2015 with a geothermal (renewable share) heat production of about 5,700 GWht. 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.
Binary power plant technologies like organic Rankine and Kalina cycle allow electricity production at temperatures down to 100 °C. This circumstance, combined with feed-in tariffs, makes geothermal power production economically feasible even for countries like Germany, lacking high enthalpy resources at shallow depth. With the commissioning of the 4.3 MWe power plant at Grünwald/Laufzorn at the end of 2014, the installed geothermal electrical capacity in Germany reached 34.5 MWe and a geothermal power production of 151,05 GWhe in 2015.
Besides supporting R&D projects, the Federal Government of Germany incentivizes new projects with the above mentioned feed-in tariff for geothermal electricity under the Renewable Energy Sources Act (EEG). The amendment of the EEG with improved conditions for geothermal energy came into effect on 1st January 2012. The subsidy for geothermal electricity was 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 came into force in an amended version in 2011, mainly aims at the installation of renewable heat sources in buildings.