Your Daily Dose of Climate Hope: June 26, 2025
Finland's epic sand battery!
Finland has built the world’s largest-ever sand battery!
Tell your state leaders to support novel energy storage projects!
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Reasons For Hope
The world’s largest-ever sand battery has come online in Finland, created by Finnish startup Polar Night Energy. The Pornainen project, standing 13 meters high and 15 meters wide, uses 2,000 tons of crushed soapstone (obtained as a by-product from a fireplace manufacturer) to deliver 1 MW of fuel oil-replacing thermal power. Routing electricity into the sand battery generates heat from the friction as the charge interacts with the sand particles, storing heat at 500°C for weeks on end. A heat exchanger then deploys that heat when needed to warm water for nearby homes.
In total, the battery can supply close to one month’s district heating demand in summer and one week’s district heating demand in winter — and it can be recharged with electricity from the grid. It will allow the town of Pornainen to reduce its consumption of wood chips for heating by 60% and to stop using fuel oil for heating entirely, reducing its emissions by 70%.
“We want to build a hundred times larger storages around the world as fast as possible.”
— Markku Ylönen, cofounder of Polar Night Energy.
This is an awesome brand-new and ready-to-go energy storage technology with immediate applicability to help heat homes across America and the world! U.S. state leaders can help empower innovators to build sand batteries in America by proactively supporting and incentivizing sand battery projects (and novel energy storage concepts in general!), with supportive legal and regulatory structures plus a fast-track permitting process.
