It’ll take another thousand square miles for the back-up generators and diesel fuel storage. Brilliant!
Get a clue. Engineers do this all the time when thinking about the feasibility of a project.
It was just a calculation of the area required, not a proposal to build it all in one place. IF it is ever built, it would be distributed over a large number of sites. Just the transmission lines from one central location would be huge and impractical.
If the result had been a 1000 mile square we would give it up as completely impractical, but the total area easily fits into the US. Of course it would be distributed, but the relatively small size of the total area is encouraging.
Of course.
But the problem is that all suitable sites are a couple thousand miles from the east coast corridor (Virginia to Maine) where the largest percent of power is consumed.