With the aim to solve green energy’s biggest problem, a group of Finnish researchers has installed the world’s first fully working “sand battery”. According to researchers, this new move could solve the problem of year-round supply, a major issue for green energy. For the purpose of the sand battery fixture, the team used low-grade sand that charges the devices with heat from cheap electricity coming from either solar or wind energy.
The annual average temperature in Finland is relatively high in the southwestern part of the country with quite mild winters and warm summers, and low in the northeastern part of Lapland. According to Polar Night Energy, Finland just opened its first commercial sand battery at the premises of “new energy” company Vatajankoski, a few hours out of Helsinki. The sand battery installed could help homes warm during winter when electricity is more expensive. The battery can store energy and heat up to 500 degrees Celsius and thus helping homes to get the required amount of electricity.
The decision also comes in the wake of the Russia-Ukraine conflict. Finland has the longest Russian border in the EU but Moscow on the other hand halted the supply of gas and electricity after Finland’s decision to join NATO.
The working procedure
The sand battery is a thermal energy storage system that is built around a big, insulated steel tank – around 4 meters (13.1 ft) wide and 7 meters (23 ft) high – full of plain old sand. When this embedded sand is heated, with a simple heat exchanger buried in its middle, the device will store 8 MWh of energy at a nominal power rating of 100 kW. 500–600 °C.
When needed, the energy is extracted again as heat in the same manner. Further, to feed the local district heating system, the locality uses this stored heat, combined with additional heat from its own data servers, which use piped water to transfer heat around the area. Later it will be used to heat buildings, swimming pools, industrial processes, or in any other situation that requires heat.
However, questions are being raised by many experts on weather forecast studies around the world. Many questioned how do we keep the lights on when the sun doesn’t shine and the wind doesn’t blow? The answer given by researchers mentions that large-scale batteries can store and balance energy demands as the grid becomes greener.