The world needs more batteries! This is a new one on me.
“A “sand battery” is a high temperature thermal energy storage that uses sand or sand-like materials as its storage medium. It stores energy in sand as heat. “
This could be interesting if it were efficient (but it’s not really…yet…) It basically takes us back to the steam engine (or more likely steam turbine) which is old tech. But this is fine, it is about storing and being able to use energy.
Have a look, they are selling it, but I get the feeling not many are buying.