Researchers have installed in western Finland the world’s first fully functional sand battery, which can store “green” energy for months. The installation was done in a small factory of an electricity company (Vatajankoski) and the battery works quite well, showing that in the future it could still be an alternative solution to the big energy problem that currently exists internationally, mainly as a result of the Russian invasion of Ukraine. The device is charged with heat generated by cheap electricity from solar or wind power. The sand stores heat in hot air that circulates inside it at a temperature of about 500 degrees Celsius and then heats e.g. domestic water during the winter, when energy is more expensive. The new energy crisis – which could get worse if Russia further shuts off its gas tap to Europe in retaliation for sanctions against it – has highlighted the critical importance of renewable and alternative energy sources.
But a key problem is how to maintain a supply of “green” energy to the electricity grid when there is no sun or wind for solar panels and wind turbines to work properly. Therefore, the importance of energy storage systems, such as large batteries, which will ensure the stability of current around the clock and in all seasons, has become evident. But most batteries are lithium and therefore expensive, so new technologies are being sought in this area. And sand, which has the advantage of being abundant, is one of them. The sand battery is the creation of young Finnish engineers who have created the company Polar Night Energy, according to the BBC. The big question is whether the new technology can be scaled up to really make a difference, and whether it will be possible to use the sand battery to generate electricity in addition to heat. So far, battery efficiency drops dramatically when sand is only used to generate electricity for the grid. The aim is to improve the battery so that it can store both “green” electricity and heat for a long time. Other research groups in the US and other countries are also studying sand as a form of battery for “green” energy. But the Finns are the first to develop a fully functional commercial system with satisfactory energy efficiency.