It seems a long time ago now since I first proposed the possibility of pumped storage at Lake Onslow. But just confirming - having the equivalent amount of ener

It seems a long time ago now since I first proposed the possibility of pumped storage at Lake Onslow. But just confirming - having the equivalent amount of energy (4-5 TWh) in batteries would be impossibly expensive. Also, the batteries would need to be replaced from time to time.