Helsinki: The world's first ever completely functional sand battery has been installed in Finland. It can sustainably generate heat for a long time and keep homes warm throughout the winter.
The first commercial unit has been built at Vatajankoski in western Finland. It will be providing heat for the district's heating network in Kankaanpaa.
According to Polar Night Energy which created the battery, the core of the technology is its patented high-temperature, large-scale heat storage. The sand battery functions using electricity produced by solar or wind energy. It uses electricity to heat 100 tonnes of sand. The company claims this will enable the up-scaling of solar or wind energy for up to 100% of heating and electricity demands in the country.
The innovative technology first converts electricity to heat and then stores it for later use. "We use sand as the storage medium, which leads to safe operation and a natural balance in the storage cycle. Additionally, sand is a cheap and abundant material that can be heated up to 1000 degrees Celsius and even higher."
Speaking about its application, Polar Night Energy said the heat transfer system that enables effective energy transportation to and from the storage is inside the sand. "Proper insulation between the storage and the environment allows for months of storage with minimal heat loss."
Lead scientist Ville Kivioja said the sand at the core is very far from the boundary. The heat stored in the core lasts for days or even weeks. "If we look at the sand in the steel silo, then some of this sand is quite close to the boundary structure, say, a distance less than 0.5 meters. This portion of the sand will conduct the heat quite effectively to the boundary structure, and thus this heat gets partly lost over time," reported Down To Earth.