I think the estimate for an installation that would provide enough electricity for the US was 2000 acres of Mojave desert covered in cells, at a cost of about $1trillion, and the distribution and storage was another 1.3trillion, over 10 years.

Which frankly, is probably not a patch on what is spent by the military ensuring access to foreign oil by shooting brown people and propping up genocidal maniacs, and making themselves a target for terrorists.