> When talking about the electrical grid you have to be able to generate energy in any amount whenever you want.

I think there is an error thinking this way.

It is like saying "everyone must own a pickup truck, because they must be able to move any household appliance or furniture item at any time."

"nobody can drive an electric vehicle because they must be able to drive to the next state at any time."

Honestly, you can have a very reliable electrical grid that is runs on solar/wind/batteries for most of the time.

Batteries enhance the grid, and if there was a period of no wind or no sun, it is quite easy to spin up gas turbines for a day or a month.