Finland, famous for its long winters, has long struggled to produce renewable power during the colder months given the lack of heat and light. Finland’s source of power has always been from Russia, the war between Russia and Ukraine led to the innovation of the ‘sand Battery’ which was developed to serve as an alternative means of energy for Finland.
The creation of this “sand battery” might also solve a problem faced by the global renewable energy industry, that of year-round sustainability. The sand contains a heat transfer system that permits energy storage and helps to transfer energy from one medium to the other. It also contains insulation which prevents energy loss for up to a month.
It is the first commercial battery that uses sand, which they believe can solve many of the problems with battery storage. The battery, located in the town of Kankaanpää, is attached to the district heating system.
The battery is made of a four-meter by seven-meter steel container that contains hundreds of tonnes of sand. Allowing the system to keep the sand at 500 degrees Celsius for several months during which time it will continue to heat the nearby air. The process uses resistive heating where hot air is generated and circulated in the sand using a heat exchanger. Using very little energy, the sand can be kept hot for months. When energy is needed, the battery discharges the hot air, which is used to warm water which is then pumped around homes, offices, and even the local swimming pool.
All in all, the “sand battery” offers 100 kW of heating power and 8 MWh of energy capacity which can be piped into the city’s district heating system.