Finland Launches 100-MWh Sand Battery, Cutting Heating Emissions by Nearly 70%
Updated
Updated · CNBC · Jul 25
Finland Launches 100-MWh Sand Battery, Cutting Heating Emissions by Nearly 70%
3 articles · Updated · CNBC · Jul 25
Summary
Pornainen in southern Finland has put into service the world’s largest commercial sand battery, using 2,000 metric tons of crushed soapstone to store 100 megawatt-hours of thermal energy for district heating.
The 13-meter-high, 15-meter-wide system charges when wind and solar power make grid electricity cheap, then releases stored heat for up to one week in winter or nearly one month in summer.
Polar Night Energy and Loviisan Lämpö said the project has cut district-heating greenhouse gas emissions by almost 70% and wood-chip use by about 60%, while a wood-chip plant remains for backup and peak demand.
Loviisan Lämpö aims for the battery to supply 55% to 60% of the municipality’s district heating in the first months of this year, up from roughly 30% in 2025.
The project is about 10 times larger than Finland’s 2022 pilot, underscoring global interest in long-duration heat storage even as sand batteries still face scaling limits, including low energy density and weak heat-to-power conversion.