Finland has recently activated the world’s largest sand-based battery, marking a significant advancement in thermal energy storage technology. This innovative system utilizes sand or crushed rock to store heat, which is generated using electricity, typically sourced from renewable energy. The stored heat can later be harnessed for various applications, such as heating buildings.
The economic advantages of this sand battery are noteworthy. Located in the small town of Pornainen, the battery employs crushed soapstone—essentially waste material discarded by a local fireplace manufacturer. While it may not boast the visual appeal of a large lithium-ion battery, the 2,000 metric tons of pulverized rock housed within a 49-foot-wide silo is expected to significantly reduce carbon emissions in Pornainen. This initiative aims to replace the expensive oil currently used in the town’s district heating network.
Like many towns in Scandinavia, Pornainen relies on a central boiler to heat water for residential and commercial buildings. The sand battery, developed by the Finnish company Polar Night Energy, has the capacity to store 1,000 megawatt-hours of heat for weeks, which is sufficient for a week of heating during the frigid Finnish winter months. The system is designed to minimize heat loss, with only about 10% to 15% of heat dissipating during storage and recovery. The outlet temperature can reach as high as 400°C. Furthermore, the sand battery is projected to decrease wood chip consumption in the district heating system by approximately 60%.
In addition to heating, the heat stored in the battery has the potential to be converted into electricity, albeit with some loss of efficiency in the process.
As the costs of renewable energy have decreased, interest in thermal battery technology has surged. Numerous startups are exploring similar innovations. For instance, Scotland-based Sunamp is developing a thermal battery using materials that flavor salt-and-vinegar potato chips. Electrified Thermal Solutions, which was a runner-up at TechCrunch’s Startup Battlefield 2023, has created a type of brick that can generate heat approaching 2,000°C, while Fourth Power is working on graphite blocks capable of storing electricity as heat at 2,400°C.
The sand battery in Pornainen is charged with electricity from the grid, taking advantage of the low prices during off-peak hours. Finland’s electricity grid is predominantly powered by renewables (43%) and nuclear energy (26%), making it one of the cleanest in Europe. The cost of electricity in Finland is also the lowest in Europe, at just under €0.08 per kilowatt-hour—less than half the EU average. Although Polar Night has not disclosed the specific costs associated with the project, the raw materials are inexpensive, and the construction of the system is relatively straightforward. A smaller prototype developed a few years ago was estimated to cost around $25 per kilowatt-hour of storage, suggesting that the new version may be even more economical. In contrast, lithium-ion batteries currently average about $115 per kilowatt-hour.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/finland-launches-worlds-largest-sand-battery-with-promising-economic-benefits/
