I'm not following the math. Taking the US as an example: depending on who you ask, we could generate enough power for the US with somewhere between 10000 squar

I'm not following the math. Taking the US as an example: depending on who you ask, we could generate enough power for the US with somewhere between 10000 square miles (Elon math) and 21250 square miles (pretty common number given by multiple other sources) of PV. That is about a fifth of the state of Nevada. A lot of PV, to be sure, but far from beyond hope. And that assumes nothing but PV, which is unrealistic. We capture a bunch of the sun's energy as wind and rain.