A small town of about 5,000 people north of Helsinki in Finland is preparing to switch from fossil fuel energy to heat its homes to relying on heat being stored in a ‘battery’ made up of crushed rocks from the construction industry.
As described in this article, “The energy-storing structure measures about 13 metres tall and 15 metres wide and is filled with 2,000 tonnes of crushed soapstone, a byproduct of the construction industry. The new battery is 10 times larger than the startup’s first pilot plant in Pornainen, launched in 2022.”
“When renewables are abundant, like on a sunny or windy day, clean electricity is wired to the battery. There, it powers a heater that sends hot air through a series of pipes into the giant vat of sand, heating it to a toasty 600°C. Thanks to the battery’s insulated wall, this energy can be stored for weeks or even months. When needed, the battery discharges the hot air on demand — warming water in the district heating network. This can provide heat to households, factories, and even swimming pools.”
Could a battery of this type work in your town or city?