Finland's Sand Battery Tackles Renewable Energy Storage Challenges

Pornainen, Finland – A small town in southern Finland has deployed the world's largest commercial sand battery to combat the intermittency of renewable energy sources. The facility, standing 13 meters tall and 15 meters wide, uses 2,000 metric tons of crushed soapstone to store clean energy in the form of heat.

The system provides 100 megawatt-hours of thermal energy, capable of covering nearly a month's heating demand in the summer and about a week's demand in the winter for Pornainen's 5,000 residents. Commissioned by Loviisan Lämpö and developed by Polar Night Energy, the battery was launched last year.

This project aims to reduce carbon emissions from the local district heating network, with estimates showing a nearly 70% cut in greenhouse gases and a 60% reduction in wood chip usage. Previously, the town relied on oil and wood chips for heating.

Tommi Eronen, CEO of Polar Night Energy, highlighted the need for new storage solutions in the energy transition. "Hopefully a big portion of those storages could be sand battery-type of storages where we don’t need rare earth materials," Eronen stated, contrasting it with chemical batteries.

The sand battery operates by heating the material within a large, insulated silo when electricity is abundant and cheap. The stored heat is then released via heat exchangers to warm water for the district heating network, offering a flexible and efficient energy storage solution.