[Schroedingersat]

> Where is all that storage going to come from?

A large variety of places, but not by replacing 100% of electricity and only electricity in one region at a time.

You replace 30% of electricity. That's easy.

Then you replace a bunch of dispatchable non electric loads and use the times the new generation can produce electricity to replace another 20.

Then you add a bunch of 4 hour storage and dirt cheap thermal storage. You get another 20.

Then if there's finally a breeder reactor it can join the party, otherwise you round out the rest with storage as the price plummets. Burner reactors are irrelevant.