Pornainen Sand Battery

Polar Night Energy delivered the Pornainen Sand Battery to Finnish district heating company Loviisan Lämpö as a turnkey project. It is the primary production plant of the local heating network, with 1 MW of heating power and up to 100 MWh of thermal storage, about ten times larger than the Sand Battery running in Kankaanpää since 2022. The storage medium is 2,000 tons of crushed soapstone, a by-product of Tulikivi's fireplace production, which reaches a maximum storage temperature of 400 °C. The battery charges from the grid using optimized algorithms, mainly at low spot prices. It is designed to take part in reserve and balancing markets, with Elisa optimizing its charging and reserve market participation. The existing woodchip plant stays on as a backup and peak-load facility, and the network's emissions are expected to fall by 70%, around 160 t CO2e per year.