3 ms·Sorry to a noob can someone explain this please. They are just heating up sand right?by ionwake 3y agoSorry to a noob can someone explain this please. They are just heating up sand right?loeg 3y agoYep.Ekaros 3y agoYep, combined with district heating that works with simple heat exchangers, it is pretty decent system. So you either pump power to sand or take heat from it and put it heating network.