Bern examines geostorage for district heating


Bern – The city of Bern will test a heat geostorage system in a research project. Heat generated in summer from waste incineration is to be stored in sandstone layers at a depth of around 500 meters. In winter, it will be used as district heating.

According to a statement from the Swiss Federal Office of Energy ( SFOE ), Energie Wasser Bern (ewb ), a utility company in the city of Bern, is planning a research project to investigate the feasibility of an underground heat storage facility. For this purpose, a borehole was drilled into a sandstone layer 500 meters deep near the Forsthaus energy center. This is where ewb intends to discharge and store the heat generated from waste incineration in the summer so that it can be used to heat Bernese apartments in the winter.

According to the announcement, heated water will be introduced through a main borehole and heat the porous sandstone. The cooling water is drawn off again via secondary holes, and the heat remains in the stone. In winter, the process is reversed. Cold water is introduced through the secondary wells and heated before being withdrawn through the main well. District heating, according to the announcement, could heat up to 1500 larger apartments.

The project is budgeted at 33 million francs. Of the costs, ewb bears 44 percent. 51 percent is covered by the Swiss Federal Office of Energy, which is funding the pilot project. The remaining 5 percent is financed by the Eco Fund of the City of Bern.

“ewb’s project can be described as a frontrunner project as far as high-temperature heat storage in Switzerland is concerned,” explains Christian Minnig, geothermal specialist at the Swiss Federal Office of Energy. “It also provides valuable information on the utilization potential of deep geothermal energy. Hence the SFOE’s large and broad-based financial commitment.” eb