Finland has recently opened the world’s largest sand-based battery in the small municipality of Pornainen. This innovative energy storage system, developed by Polar Night Energy, promises to transform the way the region manages heating during the frigid winter months.
The sand battery has an extraordinary capacity, with the ability to store energy as heat for over 1,000 megawatt-hours for weeks at a time. This accumulated heat can cover Pornainen’s heating requirements for a week! Though its name may evoke feelings of movement and excitement, it has a calmer purpose as a vital resource during Finland’s extreme winter months. The battery is charged with clean energy from the country’s electricity grid. This substantial grid is powered largely by renewable energy, with 43% from renewables and 26% from nuclear.
One key advantage of this sand battery. Operators can draw on electricity supply when prices are low, maximizing the benefit from Finland’s largely clean and low-cost power supply. This smart growth approach improves economic competitiveness while advancing environmental goals.
Carbon emissions impact Pornainen As much as the battery is an economic boon for Pornainen, its effect on carbon emissions is significant. As the town looks to new energy sources, they are already operating a central galvanic boiler that heats water for homes and buildings. The sand battery will reduce the amount of wood chips used by the district heating system by about 10 percent. We expect that to be cut by more than 60%. The now fully-functioning prototype battery employs crushed soapstone as its chemical storage medium. This byproduct from Finnish fireplace manufacturing is a testament to its ecological design.
The sand battery stores 2,000 metric tons of pulverized rock in a 49-foot wide silo. It’s incredible efficiency from 85% up to 90%. This corresponds to a net heat loss in storage and recovery of between 10% and 15%. Moreover, the outlet temperature of the process can be as high as 400°C, so it is a suitable solution for industrial heating applications.
Due to the low cost of materials, the sand battery works out to around $0.08 per kilowatt-hour. That’s less than half the average toll rates in the European Union! That low cost makes it a highly attractive solution for municipalities that want to invest in sustainable energy solutions.