Finland has announced the creation of a 1 MW “sand battery” capable of retaining heat ten times more efficiently than similar existing installations. The technology will be used during cold polar winters.
The project from Polar Night Energy is a steel tank filled with sand, heated through a heat exchanger using excess grid electricity. It is often generated from renewable sources. The new technology involves storing such energy for several months with minimal losses. Afterwards, utilities will be able to extract it in the form of heat to heat households.
The project will allow the supply of heat to the local district heating system, distributing the accumulated energy in the form of hot water or steam to heat houses, buildings and even swimming pools. For the first time, a sand battery will be used in the central heating network of the Finnish municipality of Porninen.
The design, with an output power of 1 MW and a capacity of 100 MWh, will cover the weekly heat demand of the residents of Porninen in winter or the monthly demand in summer. The dimensions of such a battery will be 13×15 meters. In addition, it will reduce carbon dioxide emissions in the district heating system by 160 tons per year, which is 70% lower than usual.