6
At Polar Night Energy, co-founders Tommi Eronen and Markku Ylönen use sand to store wind and solar energy as heat, providing a cleaner alternative for warming homes and businesses. The company’s first industrial-scale sand battery went into operation this summer, contributing heating for the 5,000 residents of Pornainen, Finland, and using crushed soapstone left over from a fireplace manufacturer. Polar Night Energy has started testing samples shipped from interested customers around the world, analyzing grains for their heat-storing capacity. “We can use all kinds of different sand-like materials,” Eronen says.
