Finland's sand batteries offer a low-cost thermal storage solution for renewable energy

Finland's Polar Night Energy is developing "sand batteries" — large-scale thermal energy storage systems that use sand as a medium to store heat generated from excess renewable electricity. The sand is heated via resistance heating and can retain heat for long periods, offering a low-cost, durable solution for renewable energy storage challenges. The article features an interview with Annette Höglund-Dönnes, who explains the technology's potential role in the energy transition, particularly for industrial heat and district heating applications.