If we install enough solar where 100% of our daytime load is served by solar, that’s great. But what about when the solar starts to drop off later in the day?

Store the surprus of energy from the solar panels and use that as a buffer with batteries or gravity

But some gas units take literal hours to turn on. And if you’re 100% renewable during the day, you can’t have those gas units already online.

Why not? Just time it and start it hours before, wind energy could help in that too