So far geothermal energy has been utizilized by heat pumps in Finland. Large geothermal power stations using bedrock’s deeper energy resources are now at initial stages.
St1 is carrying out a pilot project on a geothermal plant in Otaniemi, Espoo. It has drilled two over 6 km deep holes, heat wells, between which water will be circulating. Permeability of the bedrock and thus water circulation will be enhanced via stimulation, i.e. pumping water with a high pressure to the heat well. Pressurized water opens new pathways between fracture zones, which will cause small so called induced earthquakes. The induced earthquakes have been monitored both by St1 and Institute of Seismology. The stimulation of the firstly completed heat well was performed in summer 2018. Thousands of small induced earthquakes took place, the majority of which were only observable with specific seismological instruments. Additional information on geothermal energy and induced earthquakes can be found in a report by the Institute of Seismology.
The final preparations of the second heat well are taking place. A new counter stimulation phase has been scheduled to early May. Also this phase may induce earthquakes, some of which are observable by citizens. For more information turn to a release on St1 website.
The Institute of Seismology, University of Helsinki, would like the public to report unusual, transient observations associated with ground vibrations. The observations will help scientists and authorities to investigate and assess the phenomena. The observations are used for non-commercial purposes only and the responses will not be forwarded to third parties.