All media releases · 03. October 2025

Geo-Energie Jura SA (GEJ) has successfully completed the exploration phase of the Haute-Sorne (Canton Jura, Switzerland) geothermal pilot project. Tests conducted in July in the deep borehole confirm that rock permeability can be increased sufficiently to create a usable geothermal reservoir—while complying with the prescribed seismic thresholds. Geothermal energy is available around the clock, produces no CO₂ emissions, and is an ideal complement to other renewable energy sources.

All media releases · 28. August 2024

A depth of 4,000 metres was reached in less than three months. This is the first borehole in the Swiss Jura Arc between Geneva and Basel to have been drilled entirely through the sediments and deep into the crystalline bedrock. Thanks to the scientific and technical expertise applied both before and during the construction work, the borehole was drilled, cased and cemented to a high standard without any impact on safety or environmental quality. The work yielded the data required for the next ph