In a groundbreaking development, Finland has recently activated the largest sand-based battery in the world, a remarkable innovation that promises to revolutionize energy storage and sustainability.
This unique sand battery operates as a thermal energy storage system, utilizing sand or crushed rock to retain heat. Renewable energy sources are harnessed to heat the sand, which can later be utilized for various applications, including heating residential and commercial buildings.
The economic advantages of this technology are striking, particularly given that the crushed soapstone used in this project was essentially waste material from a local fireplace manufacturer. This innovative approach not only reduces costs but also promotes sustainability by repurposing materials that would otherwise contribute to landfill waste.
While it may not have the sleek appearance of traditional lithium-ion batteries, the 2,000 metric tons of pulverized rock contained within the 49-foot-wide silo is set to significantly reduce carbon emissions in the town of Pornainen. This initiative aims to replace the expensive oil currently used in the town’s district heating network, marking a significant step towards cleaner energy solutions.
Similar to many towns in Scandinavia, Pornainen relies on a central boiler system to provide heating for its residents. The newly installed sand battery can store an impressive 1,000 megawatt-hours of heat for extended periods, sufficient to meet a week’s heating needs during the harsh Finnish winters. The system is designed to minimize heat loss, with only about 10% to 15% of the heat dissipating during storage, and can deliver outlet temperatures reaching up to 400°C.
In addition to its primary function, the sand battery will also contribute to reducing the town’s reliance on wood chips for heating, potentially decreasing consumption by around 60%. Furthermore, while the heat generated from the battery could be converted into electricity, this process may involve some loss of efficiency.
As the cost of renewable energy continues to decline, interest in thermal battery technology is on the rise. Beyond the efforts in Finland, numerous startups are exploring similar innovations. For instance, a company based in Scotland is developing a thermal battery that utilizes a compound found in popular snack foods, while another startup has created a type of brick capable of generating heat at extremely high temperatures.
The sand battery in Pornainen is charged using electricity from the grid, allowing operators to take advantage of lower energy prices. Finland’s energy mix is predominantly composed of renewable sources (43%) and nuclear power (26%), resulting in a cleaner electricity supply. Additionally, the cost of electricity in Finland is among the lowest in Europe, making this project even more economically viable.
While the exact cost of the sand battery project has not been disclosed, the affordability of raw materials and the simplicity of the design suggest that it is likely to be more cost-effective than traditional energy storage solutions. Previous prototypes have indicated a storage cost of around $25 per kilowatt-hour, significantly lower than the current market price for lithium-ion batteries, which averages around $115 per kilowatt-hour.
This innovative project not only highlights Finland’s commitment to sustainable energy solutions but also sets a precedent for future developments in thermal energy storage technology.