12 000 t of water is a large swimming pool (about 5 Olympic pools) and could be used as such, perhaps. Edit: using hydrogen for steelmaking or other reductive

12 000 t of water is a large swimming pool (about 5 Olympic pools) and could be used as such, perhaps. Edit: using hydrogen for steelmaking or other reductive processes yes; for energy storage, we have better choices. You'd make it as you need it.