More Abandoned Mines Could Provide Geothermal Heat
The Institute of Geology at Tallinn University of Technology is looking for ways to expand the use of underground water in closed mines to heat local homes in Ida-Viru County.
This manmade geothermal resource exists in ten closed oil shale mines in the northeast. One of the mines, Sompa, has been used for most of the last 12 months to heat homes in the village of Kiikla through heat pumps. It is estimated to have cut heating costs there nearly by half: from 109 to 58 euros a megawatt-hour.
“This boiler plant has been in operation for well over a year and works quite well, as we see it," Jana Pavlenkova, development adviser to the Mäetaguse municipality, told Põhjarannik.
In the process, water at a temperature of 7-8 C is drawn from a mine, compressors are used to bring part of the water up to 75 C, and the cold water, now just 2 C, goes back to the mine. At peak times, 74 m³ of water per hour is extracted.
The Sompa facility is seen as a pilot project for the region. While the pipes to and from the mine to the new boiler plant in Kiikla are 1.2 and 1.5 km long, the next candidate in line is just 500 meters from a mine.
"The easiest way would be to introduce heat pumps to the Kose settlement, as it is just 500 meters from Ahtme, where water flows out of a mine. The warmth of that water could be used in a heat pump," Veiko Karu, a Ph.D. student at the Institute, told ETV.
Kristopher Rikken