Sand Batteries Are a Game Changer for Clean Energy
Haley Zaremba is a writer and journalist based in Mexico City. She has extensive experience writing and editing environmental features, travel pieces, local news in the…
This month, Finland switched on the world’s biggest sand battery, which will “enable residents to eliminate oil from their district heating network, thereby cutting emissions by nearly 70 percent ,” according to Euro News. And if it keeps running as cheaply and efficiently as it appears to be doing now, don’t be surprised if sand batteries start popping up around the world – even in your neck of the woods.
The battery, built by Finnish company Polar Night Energy, employs a form of thermal energy storage by using excess clean electricity to heat sand to searingly high temperatures. The sand holds onto this thermal energy, to be released back to the grid as needed to heat homes and provide energy for local industry. This isn’t Finland’s first sand battery, but it’s far and away its biggest. The groundbreaking model in Pornainen, Finland is an insulated silo measuring 13 meters tall and 15 meters across, and holds 2,000 tonnes of soapstone that has been crushed into sand. The sand is “remarkably efficient at maintaining its heat, losing only 10 percent to 15 percent from storage to recovery,” according to The Cool Down.
Altogether, the model can hold a whopping 100MWh of energy for weeks at a time, which would be enough to heat the entire town center even in the middle of a Nordic winter, according to a recent report from the World Economic Forum. When the heat from the battery is released, it can still be as hot as 400º Celsius (752º Fahrenheit).
