Outside AI independently uncovering some energy breakthrough there is nothing it can do to help, only hurt. We already have a source of clean, cheap, unlimited energy, we aren't rolling it out the way we could and should because some rich people would rather have us on a subscription plan where we literally light our source of energy on fire so we have to keep coming back for more.
AI has already pushed fusion research forward.
We could certainly do better but switching isn't as simple as you imply. You also conveniently left out the part where activists historically blocked nuclear buildout.