Two 7 km-deep wells are to be drilled near an existing district heating plant, which is operated by Fortum and serves the city of Espoo. The wells, with the natural cracks in the bedrock, will function as underground heat exchanges, which will be connected to the district heating plant through a pipe system. The drilling process is expected to take six months according to the project developer, Finnish clean energy firm St1.
When completed in 2017, the geothermal heating system is planned to supply up to 40 MWth, which will be sold to Fortum and is expected to cover up to 10% of Espoo’s heating demand.
‘This geothermal heat project is a key part of Fortum’s plan to shift to carbon-neutral district heating in Espoo by 2030,’ said Heli Antila, Fortum’s Chief Technology Officer. ‘In addition to geothermal heat, we will diversify our district heating production by using wood-based fuels and waste heat. This will enable us to significantly reduce the carbon dioxide emissions of our heat production and to offer cleaner district heating for the citizens of Espoo.’