Polar Night Energy to build second power-to-heat-to-power sand battery in Finland

Polar Night Energy to build second power-to-heat-to-power sand battery in Finland The sand battery pilot plant, to be constructed in southern Finland, will build on the startup’s existing technology and test the energy storage system’s ability to convert heat back into electricity. May 1, 2025 Patrick Jowett Distributed Storage Energy Storage Energy Storage Markets Technology Technology and R&D Finland Polar Night Energy's sand-based thermal energy storage system, developed for supplier Vatajankoski Image: Polar Night Energy Share Finnish startup Polar Night Energy has announced a new pilot project that will test the next generation of its sand battery technology. The sand battery pilot plant will build on the company’s existing technology, which stores thermal energy for industrial or district heating, and will be capable of converting the stored thermal energy back into electricity, a process known as Power-to-Heat-to-Power (P2H2P). The project will be built in Valkeakoski, southern Finland, in collaboration with Valkeakosken Energia, an energy company owned by the city. Construction is due to begin in autumn this year. The site will feature a thermal energy storage unit and technical building covering nearly the entire plot. A statement from Polar Night Energy says the project will operate at significantly higher temperatures than current sand batteries used for heat production. It adds that achieving these higher temperatures and overcoming related material technology challenges are key goals for the project, which will run through early 2027. Polar Night Energy says the technology has the potential to significantly cut emissions and make renewable energy sources including solar and wind more reliable and cost-effective. “When operational, the new sand battery would enable a better match between electricity production and consumption, thereby supporting the growth of wind and solar energy,” the company says. Markku Ylönen, Polar Night Energy CTO, adds that Valkeakosken Energia has identified a suitable site for the pilot, with the heat generated to be fed into the energy company’s district heating network, helping to reduce energy waste. Polar Night Energy says it is working towards delivering commercial-scale electricity production plants in the future. Last year, Polar Night Energy announced plans for a 1 MW sand-based heat storage battery in the municipality of Pornainen, southern Finland. It began testing the project in November. The company also secured €7.6 million ($8.2 million) in seed funding last year. In 2022, it switched on the world’s first commercial sand-based, high-temperature heat storage system in the Finnish city of Kankaanpää, with 100 kW of heating power and 8 MWh of energy capacity.  This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: editors@pv-magazine.com. Leapting rolls out PV module-mounting robot 03 February 2025 Leapting will soon deploy a PV module-mounting robot at a project in Australia. It says the automatic installation speed of the AI-driven machine can...