St1 Deep Heat Project: Geothermal energy to the district heating network in Espoo

Abstract St1 Deep Heat Project with its two deep wells extending to 6.2 - 6.4 km depth is the world’s deepest industrial geothermal energy project. The aim build an EGS (enhanced system) at of about 5 6 km. project a pilot aiming exploring technical and economic feasibility in crystalline rock conditions Finland for production thermal power district heating network. Due demands heating, produce hot fluid 100°C re-inject it formation 50°C. goal requires drill depth. site located Espoo, next Fortum plant on Aalto University campus. So far (2020) has drilled 2 completely cored hole (OTN-1), OTN-2 OTN-3 Hydraulic conductivity been enhanced by hydraulic stimulation both 2018 2020. extreme level sets significant challenges drilling stimulation, as well controlling induced seismicity. At present, proceeds installation pumps OTN-3, first test cross-hole pumpings are expected start January 2021. In presentation we provide insight major achievements challenges.