The world’s largest sand battery was created in the Finnish town of Pornainen. It is a thermal storage system that stores energy in the form of heat using sand or crushed stone. About this informs TechCrunch.
This technology works by heating sand with electricity, usually from renewable sources. In the future, the accumulated heat is used for various needs, in particular for heating buildings.
In Pornainen, crushed soapstone, a by-product of the Finnish quarrying industry, is used instead of ordinary sand. 2,000 tons of this material is stored in a 15-meter-wide bunker. Among the non-obvious advantages of the technology are the reduction of carbon emissions and the reduction of the community’s dependence on expensive petroleum fuel.
The system was developed by Polar Night Energy. Its sand battery is able to accumulate up to 1000 megawatt-hours of heat, which is enough for a week’s heating even in harsh winter conditions. The rate of heat loss from storage to transfer is only 10-15%, and the outlet temperature can reach 400°C.
In addition, the system makes it possible to reduce the use of wood chips in Pornainen’s district heating by 60%. It can also be adapted for power generation, although this will lead to some loss of efficiency.
Other startups deal with similar solutions. For example, Scotland’s Sunamp is working on a battery that uses a chemical compound found in salt-and-vinegar chips. At the same time, the American company Electrified Thermal Solutions has created a brick capable of generating heat up to 2000°C, and Fourth Power is developing graphite blocks to store energy in the form of heat with a temperature of up to 2400°C.
