Sorry for the noob question, but isn't there always sun somewhere on the planet? Are electricity grids not globally connected, or would it be lost in transmission?
They are not globally connected. And losses become significant after a thousand kms or so. You're not going to get to the electricity to the other side of the world where the sun is shining.
You need local storage. As much as is said about batteries, the only real solution here is hydro. Expect to see every viable valley start to get dammed over the next decade or so.
