The world's largest sand battery has been launched in Finland

The world’s largest sand battery, a thermal energy storage system that uses sand or gravel to store heat, has been launched in the small town of Pornainen, Finland, TechCrunch reports.

A sand battery uses electricity, usually from renewable sources, to heat sand. The stored heat can then be used for a variety of purposes, including heating buildings.

The sand battery, located in Pornainen, uses crushed soapstone, a waste product from Finnish stone production. 2,000 metric tons of crushed stone are stored in a 15-meter-wide bunker. One of the less obvious benefits of this solution is also the reduction of carbon emissions and the city’s dependence on expensive oil.

The sand battery, developed by Finnish company Polar Night Energy, can store 1,000 megawatt-hours of heat for several weeks, enough for a week of heating even in the cold Finnish winter. It is noted that only 10% to 15% of the heat is lost from storage to recovery, and the outlet temperature can reach 400°C.

In addition, Polar Night Energy's sand battery will help reduce the amount of wood chips burned by 60%, which is also used for district heating in Pornainen. Another application of the sand battery is electricity generation, but this approach will sacrifice some efficiency.

In addition to Polar Night Energy, many other startups are developing similar projects. In particular, the Scottish company Sunamp is creating a battery that will use the chemical contained in potato chips from salt and vinegar. In another corner of the world, the American company Electrified Thermal Solutions has created a type of brick that can produce heat at temperatures up to 2000°C, and Fourth Power is making graphite blocks that store electrical energy in the form of heat at temperatures up to 2400°C.