Is Grid Storage a Good Solution?

There's over 550,000 abandoned mines in the U.S., according to a new study. If you fully charged all of them, they would run the world for a day,. But then how much longer until they're fully charged again? A million years. Bob Greene: How many centuries would it take to adapt a million mines? I think that digging the mines probably the hardest part of creating this gravity sand grid storage. It's not like let me gargantuan task and get it ready for 2030 or 2040.