Go ahead for planned geothermal heat project in Gräfelfing, Germany

Preliminary planning for geothermal use in the municipality of Gräfelfing started more than ten years ago. In 2009, seismic reflection surveys were carried out in the municipality to explore the geological structures down to a depth of 4,000 meters. The results that were subsequently received looked promising, however, the required drilling permit has not been in the hands of the municipality. It was not until 2016 that the municipality received the exploration permit from the responsible mining authority. A decision in principle by the municipal council in the summer of 2017 opened a multi-year process with an EU-wide tender for the search for a suitable general contractor.

Now progress in project planning regarding the search for a partner has been reported.

“For its geothermal project, the municipality of Gräfelfing needs a strong, experienced partner who has the technical know-how and supports the operating concept,” explains Mayor Peter Köstler. The decision of the municipality in the choice of partner has now fallen on Silenos Energy GmbH & Co. KG, a subsidiary of the Strabag Group. As the general contractor, the company will take over the drilling work as well as the implementation and operation of the district heating network. In addition to Gräfelfing, Silenos Energy is also involved in various other geothermal projects in Bavaria, including Gauting, Garching an der Alz and Fürstenfeldbruck.

On April 28th of this year, the municipality of Gräfelfing founded the project company Gräfelfing GmbH & Co. KG together with Silenos Energy. As the main shareholder and 100 percent subsidiary of the municipality, Fernwärmenetz Gräfelfing GmbH will control 51 percent and Silenos 49 percent. The aim is to supply the municipality of Gräfelfing with environmentally friendly heat from deep geothermal energy. According to an article in Merkur , the entire procedure in the individual stages is carried out in joint coordination with the committees and the municipal council. “Now we’re finally on track and can work flat out on the implementation,” said the mayor.

Next steps

Economic feasibility calculations are initially carried out as part of an approval and detailed planning phase. The project receives financial support from the German development bank KfW. According to the mayor, the total costs so far amount to around EUR 70 million for both the drilling and the construction of the network. The amount will cover the work over several years and includes public funding. The Municipal Council of Gräfelfing has already budgeted EUR 12 million for the project over the next few years.

According to the current schedule, drilling could begin in 2024. So far, the drilling time has been estimated at around six months. “Hopefully by the end of 2024 we will be able to feed in the first hot water from our own geothermal energy. […] we have to get to it now, especially against the background of the events affecting the energy supply,” explains Peter Köstler.

The project offers great opportunities for the region and beyond. According to the mayor, the project company is free to make the subsidized heat available to Planegg or the municipal utilities.