Finland has activated the world's largest sand battery in Pornainen, an industrial-scale thermal storage system that stores renewable energy as heat. This 13-meter-tall silo holds 2,000 tonnes of crushed soapstone, capable of storing 100 MWh of energy for weeks or months. Surplus electricity from wind and solar powers a resistive heater, which sends hot air through pipes to heat the soapstone to temperatures between 500°C and 600°C. This high-temperature heat is retained with a round-trip effici

Finland has launched the world’s most powerful sand battery — an innovative thermal energy storage system capable of heating an entire town for up to a week. This groundbreaking technology stores excess renewable energy by heating tons of sand to extremely high temperatures and releasing that heat when needed. It offers a clean, stable, and affordable solution for winter heating in one of the coldest regions on Earth. • The sand battery stores energy by heating industrial-grade sand to around 50