The system heats around 2,000 tonnes of crushed soapstone, retaining thermal energy for days or weeks before supplying district heating. Developers say the technology cuts reliance on fossil fuels while offering an alternative to conventional battery storage for heating networks.

Credits: Unsplash; Author: Federico Beccari;

Located in the southern town of Pornainen, the installation has reduced emissions from the local district heating network by about 70 percent and eliminated the need for oil heating. The technology stores renewable electricity when production is high and releases the heat during periods of greater demand. Developers believe similar systems could support industrial heating and renewable energy storage in other countries.