Engineering360: "Interest in thermal energy storage heats up (or cools down)"

Huge synergies with using renewable electricity from the wind or sun to heat very large volumes of earth or water underground, for either heating or cooling. At scale Underground Thermal Energy Storage is a fraction of the cost of storing energy for heat in batteries, can store heat for a long time. There is more wind in winter so such energy storage does not have to store from summer to winter, as has been done in Denmark and Holland. See Heatstore EU. https://www.heatstore.eu/