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Analysis of the potential for hydrothermal geothermal energy in Germany

Holzkirchen geothermal plant, Bavaria/ Germany (source: Turboden)
Alexander Richter 23 Apr 2020

A study conducted in 2017 looked at the hydrothermal geothermal potential of Germany with its conclusion recently presented in a webinar by Enerchange in Germany. The potential is estimated at around 2,000 MW electric or 18,000 MW thermal.

How high is the technically and economically accessible geothermal potential in Germany?  To answer this question, the Chair for Energy Systems at the Technical University of Munich (TUM) and the Geothermal Alliance Bavaria have conducted a study to find out. Christopher Schifflechner of TUM presented the results on April 17 in the webinar series “Blickpunkt Geothermie”.

A milestone in the exploration of deep geothermal energy in Germany was certainly the so-called TAB study published in 2003 by the Office for Technology Assessment of the German Bundestag (TAB) on the “Possibilities of geothermal power generation in Germany” by Herbert Paschen, Dagmar Oertel and Reinhard Grünwald.

However, this was associated with high uncertainties regarding the thermodynamic performance of the systems and the geological data on which it is based are now partially out of date. The study made no statements about the economic potential.

In 2017, a group of researchers from the Geothermal Alliance Bavaria headed by Sebastian Eyerer created a new study. The aim was to use current operating experience from existing plants to present the technical and, subsequently, the economic potential of hydrothermal geothermal energy for the generation of electricity (and subsequently also heat) in Germany. In 2020 the study was refined and published again after a scientific review.

From technical to economic potential

Based on the technical potential of the geothermal reservoirs in Germany (“Heat in Place”), the scientists calculated the amount of electricity to be developed technically. The decisive factor here is the thermodynamic performance. Based on the generation costs and the drilling costs, the team developed a function to calculate the economic potential.

In his lecture, Christopher Schifflechner presented the data basis for the calculations, explained the parameters used and how the research group carried out the calculations came to the available results.

12.2 PWhel technical potential

For the hydrothermal geothermal energy in Germany, the study showed a technical potential of 12.2 Petawatt hours electrical (PWh el). The TAB study was based on 15 PWh el. Of these, 74 percent are also economically accessible, although a drop in EEG remuneration would significantly reduce the economic potential.

So that the utilization of the geothermal reservoirs has a truly regenerative character, a usage period of 1,000 years was determined. This would provide 9.1 Terrawatt hours of electricity (TWh el) and 12.5 Terrawatt hours of heat (TWh th) from geothermal energy each year. To tap this potential, around 460 geothermal plants of the average current plant size (5 MW el / 40 MW th) are required.

The study provides a comprehensive database for the future development of the industry and shows where the trend is headed. Above all, the increasing focus on heat generation may lead to changed project characteristics.

The text above is based on a Webinar with Christopher Schifflechner of the Technical University of Munich.

For those who missed the webinar there is a recording on Enerchange’s YouTube channel (in German).

Source: our German partner website TiefeGeothermie