Government financing sought for expansion of geothermal heating in Riehen, Switzerland
Riehen, Switzerland (source: Erdwärme Riehen) )
Carlo Cariaga
6 Mar 2026
Funding of CHF 15.2 million is sought for the expansion of geothermal district heating in Riehen, a pioneering municipality for geothermal in Switzerland.
The government of the canton of Basel and the municipality of Riehen are requesting their respective parliaments to approve a conditionally repayable loan to expand the scope of geothermal district heating in Riehen, Switzerland, called the “geo2riehen” project. The funding being sought is CHF 7.6 million (approx. USD 9.7 million) from each party.
The loan will finance the 5.5-km expansion of the Riehen district heating network, new house connections, and the necessary expansion of the production facilities. This will connect 620 new properties to the network and reduce approximately 6875 tons of CO2 emissions.
Since 1994, the geothermal plant in Riehen has been supplying clean and reliable geothermal heat to about 8500 residents. It is the oldest geothermal facility in Switzerland, and currently still the largest. The system is supplied by a doublet, drilled in 1988 to depths of about 1500 meters.
The expansion of geothermal district heating in Riehen, operated by local heating company Wärmeverbund Riehen AG (WVR), had been initially proposed in 2020. It had then received CHF 1.2 million in funding from the Federal Government to execute geophysical studies to characterize the extension of the geothermal reservoir. Funding was granted for the project based on the 2018 König-Lüdin motion which promotes the direct exploitation of geothermal energy for the production of heat, with the ultimate aim of reducing the CO2 emissions of buildings. The project received the approval of the local residents’ council soon after.
A seismic survey was done in 2022, yielding encouraging results and supporting the development of a second heating plant. The results also helped identify a site in the Grendelmatten area as optimal for the drilling of new wells and the location of the plant.
Expansion of geothermal district heating will support the goal of Basel-Stadt to reduce its greenhouse gas emissions to net zero by 2037, as set by the cantonal constitution. In addition to expanding the scope of geothermal heating, 47% of the heat produced from non-renewable energy sources in Riehen will also have to be replaced.
Source: Canton of Basel-Stadt and Swissinfo.ch
