Soultz-sous-Forets

The Soultz-sous-Forêts geothermal project started in 1987, and is the cradle of the geothermal energy European research in granitic and fractured systems. After almost 30 years of research, the geothermal site is exploiting the fractured basement at 5 km depth, under commercial conditions, for the EEIG Heat Mining. The installed gross capacity of the plant is about 1.7 MW_e.

The actual geothermal system is made of three wells: one production well named GPK-2 and two injection wells named GPK-3 and GPK-4. The geothermal brine is produced at a temperature of 150°C, reaching the wellhead with a nominal flow rate of 30 kg/s provided by a Downhole production Line Shaft Pump.

The geothermal brine is then flowing through a system of three consecutive double-pass tubular heat exchangers supplying heat to an. Organic Ranking Cycle (ORC), in order to produce electricity. The geothermal brine is then fully reinjected at around 70°C, and the volume of reinjected brine is shared between the two injection wells, one third in GPK-4 and two third in GPK-3 without using reinjection pumps. The reinjection temperature is linked to the conversion process. The geothermal plant has been successfully producing electricity since September 2016 under commercial conditions.