Finnish City Inaugurates 1 MW/100 MWh Sand Battery

Summary

Support CleanTechnica's work through a Substack subscription or on Stripe. There are more ways to store energy than just using batteries. Some are using fire bricks, particularly for process heat for industries that rely on high heat in manufacturing. Others propose an arrangement of massive concrete blocks that move up and down like the weights of a giant grandfather clock, converting kinetic energy to potential energy and back again. In Finland, two intrepid engineers began experimenting with a sand battery a few years ago. As we reported when the first prototype was unveiled three years ago, the idea of a sand battery began with two Finnish engineers, Markku Ylönen and Tommi Eronen. The concept is simplicity itself. Make a really big pile of sand. Heat it with excess renewable electricity to around 500°C (932°F), then use that heat later to heat homes, factories, even swimming pools. They say the sand can stay hot for 3 months or more. The pair have founded Polar Night Energy, which constructed a prototype consisting of 100 tons of sand inside what looks like a silo in the town of Kankaanpää. Many Americans are unfamiliar with the concept of district heating, but it is widely used in other counties, especially in Scandinavia where keeping schools, municipal buildings, arenas, factories, and homes warm in winter is a challenge. Loviisan Lämpö is a Finnish district heating company that supplies district heating to customers in Loviisa, Pukkila, Pornainen, and Pyhtää. It has collaborated with Polar Night on a new sand battery — one that is much larger than the prototype — which began operating in the city of Pornainen in southern Finland this month, where it is expected to reduce carbon emissions from district heating by 70 percent. Previously, the majority of heat needed for the system came from burning oil, but that has now been completely eliminated. The system will continue to burn wood chips to supplement the sand battery. Wood chips are at least carbon neutral...