On the BBC Future Planet web page, there is an interesting article on sand batteries published on November 4, 2022. The article is available here. A new way of storing renewable energy is providing clean heat through the long Nordic nights. Read the article to know how this is done. Storing renewable energy from high-production time to high-consumption time is essential in net zero CO2 emission in order to limit global warming.
Polar Night Energy: Sand battery, https://polarnightenergy.fi/sand-battery