Bavarian geothermal plant to supply entire municipality with heat

Silenos Energy’s geothermal plant in Garching an der Alz in southern Bavaria is set to expand by 2028 to supply heat to the local district heating network. The facility, which has been operating since 2021 and has so far generated only electricity, will now supply heat to the entire municipality. The project benefits from exceptionally favourable geological conditions in the Molasse Basin and fits into Bavaria’s broader plans to significantly strengthen the role of geothermal energy in heat supply.

Silenos Energy’s geothermal plant in the German town of Garching an der Alz, located near the German Alps close to the Austrian border, is set to start supplying heat to the local heating network by 2028. The facility has been operating since 2021, but until now it has supplied only electricity to the grid.

Construction of the district heating network is expected to begin in mid-2027. The completed project will consist of a central heating plant, a distribution network and heat transfer stations in connected buildings. A peak-load boiler and a backup boiler are also planned to ensure reliable heat supply during periods of peak demand. The aim is to gradually connect the entire municipality to the network.

The geothermal plant in Garching an der Alz officially began operating in early 2021, with an installed electrical capacity of 5.2 MWe and a thermal capacity of 7 MWth. Drilling for the project began in 2018 and eventually reached the Malm formation at a depth of 3832 metres, where thermal waters have a temperature of 125 °C.

The project’s success hinges on geological conditions that are exceptionally favourable in southern Bavaria. The area lies in the so-called Molasse Basin, where thick layers of porous limestone and dolomite from the Jurassic and Upper Cretaceous periods are found. These rocks are highly permeable and allow large volumes of hot water to circulate, which is crucial to the economics of deep geothermal energy. This combination of sufficiently high temperatures and good hydraulic properties makes the region one of the most suitable in Europe.

Given the favourable geological conditions, geothermal energy has significant potential to contribute to heat supply in Bavaria. Currently, 11 plants are operating in the state, each with an installed capacity of several MW. Geothermal energy has so far met 0.6% of Bavaria’s heat demand.

Under plans announced in 2021, up to 25% of Bavaria’s heat demand is to be met by 2050 using heat drawn from warm underground water. According to statements made at the time by Bavarian Minister-President Markus Söder, the current use of this resource is insufficient, and this is expected to change in the future.