To help decarbonize the electric grid in Finland, there are plans to store excess renewable energy in sand batteries. Sand battery by Polar Night Energy and Loviisan Lämpö has very high heating capacities. It would reduce the town’s emission by 70%.
Polar Night Energy, a Finnish start-up, struck a deal with district heating company Loviisan Lämpö. They will be installing a 1 MW (1000 MWh) system in Pornainen, an area near Helsinki. Polar Night’s thermal battery technology uses sand or sand-like material because their heating capacity is around 1000° C or even higher.
As per Polar Night, the battery would cut down the town’s emissions by 70% because of its high heating capacity. In the words of CEO of Loviisan Lämpö, Mikko Paajanen, “We want to enable the growth of renewable energy. The sand battery will keep the electricity grid balanced as the share of wind and solar energy in the grid increases.”
The Pornainen battery is made from crushed soapstone and sourced from a local fireplace manufacturer. Usually for him it is a by-product that he usually throws away. But in general this material seems to have better heat conductivity than conventional sand.
This will help in building a heat transfer system inside the sand to enable effective energy transportation. Polar Night says, “Proper insulation between the storage and environment ensures a long storing period. It can stretch as long as months with minimal heat losses.”
Polar night energy’s soapstone sand batteries would be around 15 meters wide and 13 meters high. Construction and testing would take around 13 months. Sand batteries ranges from 10s to 1000s cubic meters in size and can also be installed underground.
“It’s exciting to build a large-scale thermal energy storage, which will also act as a primary production plant in Pornainen’s district heating network. This is a significant step in scaling up the Sand Battery technology,” said Liisa Naskali, COO at Polar Night.
This Sand battery by Polar Night Energy and Loviisan Lämpö is a big project. But before this they made the 1st commercial sand battery for utility in Western Finland. That was not as powerful as this newly planned one.
Several other start-ups are developing the same methods for storing excess green energy in the form of heat in thermal energy storage projects. Developers are using molten salt, bricks, and liquid tin as they are inexpensive and abundantly available.
Source: Loviisan Lämpö Invests in Polar Night Energy’s Sand Battery in Pornainen
