Finnish Town Heats Up with World’s Largest Sand Battery
▼ Summary
– A Finnish town, Pornainen, is replacing fossil fuels in its heating network with a sand battery, cutting emissions by 70%.
– The sand battery, built by Polar Night Energy, stores excess renewable energy as heat in 2,000 tonnes of crushed soapstone.
– The system heats sand to 600°C using renewable energy and releases stored heat to warm homes and businesses when needed.
– The battery can supply a week of winter heating or a month of summer heating for the town on a single charge.
– Polar Night Energy plans to expand sand battery installations globally as a cleaner alternative to fossil fuel heating.
A revolutionary sand-based energy storage system is transforming how a Finnish town stays warm, offering a sustainable alternative to fossil fuels. The innovative technology, developed by Polar Night Energy, uses crushed soapstone to store excess renewable energy as heat, providing reliable warmth for thousands of residents while drastically cutting emissions.
Located in Pornainen, just north of Helsinki, the sand battery stands 13 meters tall and holds 2,000 tonnes of crushed soapstone, a construction industry byproduct. This massive thermal storage unit captures surplus electricity from wind and solar sources, converting it into heat that can be stored for weeks. When demand rises, the system releases this energy to warm water in the district heating network, supplying homes, businesses, and even local swimming pools.
Unlike traditional heating methods that rely on burning natural gas or oil, this emission-free solution reduces Pornainen’s carbon footprint by an estimated 70%. The battery’s impressive capacity, 100 MWh, means it can heat the entire town for a week in winter or a full month in summer on a single charge. A backup biomass boiler ensures reliability during peak demand periods.
Liisa Naskali, COO of Polar Night Energy, emphasizes the broader potential of the technology. “Combustion isn’t sustainable for the climate or the environment,” she says. “Our sand battery proves that practical, scalable alternatives exist.” The company is already exploring opportunities to deploy larger versions of the system across Finland and internationally.
Heating accounts for roughly half of global energy consumption, with much of it still sourced from fossil fuels. In Europe, where natural gas and wood chips dominate, solutions like sand batteries could play a crucial role in the transition to cleaner energy storage. Unlike lithium-ion batteries, which store electricity, thermal storage systems like this one offer long-duration energy retention at a lower cost.
The Pornainen project builds on Polar Night’s earlier pilot, which was 10 times smaller. The latest iteration demonstrates how the technology can be scaled to meet real-world energy demands. With insulated walls keeping temperatures at a scorching 600°C, the system efficiently retains heat until needed.
As cities worldwide seek ways to decarbonize heating, sand batteries could emerge as a key component of the energy transition. Alongside other storage methods, such as gravity-based systems and hydropower, they provide a versatile, low-impact solution for integrating renewables into everyday life.
For those interested in cutting-edge sustainability innovations, events like the TNW Conference in Amsterdam offer a glimpse into the future of energy. Scheduled for June 19–20, the gathering brings together industry leaders to explore groundbreaking ideas. Early registrants can secure discounts using promotional codes.
This Finnish breakthrough highlights how simple materials like sand can drive meaningful change, proving that sustainable heating doesn’t require complex or costly solutions, just smart engineering and a commitment to cleaner energy.
(Source: The Next Web)
