Batteries are the key to the future of the most abundant sources of renewable energy, solar and wind power for one obvious reason: intermittence.
If power generators want to replace fossil fuels entirely, they will need to store a lot of that renewable energy for use when the sun isn’t shining and the wind isn’t blowing. Batteries, however, are expensive — especially if they involve lithium, which is not suited to large-scale energy storage.
This sand, used in the first commercial sand battery, could revolutionize the use of renewable energy. (Courtesy Polar Night Energy)
But a small six-person startup in Finland has come up with an intriguing and low-cost solution: It has developed the world’s first commercial heat-storage battery, comprising a very cheap, low-tech material.
“It’s a large mass of sand. In itself, the…