Not "just" by any stretch of the imagination. This is larger than Rhode Island and Lake Erie combined. Aka a pipe dream. Might as well "just" build a dyson sphere while we are at it.
Distributed production is super doable. Of course you won't just put a big square somewhere.
That isn't a lot. New Mexico alone can fit about 100 Rhode Islands. And NM isn't even the largest thinly-populated sunny state in the union.
https://upload.wikimedia.org/wikipedia/commons/thumb/2/2f/Wh...
If you dedicated a single (average sized) county per state to solar you'd ~3-5x the land you need for current consumption.
Further, in Nevada, the US governement owns 87% of the land give or take a percentage point.
The land is available. It's the politics and the expense required to build it.
I'm not saying musk is a clever man for pointing this out. Even greenpeace said stuff like this in the early 2000s.
the point is, it sounds bigger than it is. For oil storage, the US has something like 36 square miles of storage (converting from cubic to square isnt accurate)
He didn't say Elon was the origin.
A clusterfuck of priorities.