How much solar to run the whole U.S.?

One blogger says he's calculated the answer. It's close to 600 square miles. To provide all the electricity now used in the U.S. How does that compare to all the mall parking lots in the land? Cover them over with solar panels and...

And, of course, it depends on where you put those solar collectors. The NASA map above shows the hottest solar parts of the globe in the brightest of reddish-orange. Panels in Alaska aren't worth as much as those is a sunny part of Arizona, obviously.

Clearly solar power could have a much more productive future in the U.S. than Europe which is further north and gets shorter days in the winter. Right now Europe simply has more investment going into utility-scale solar installations.