An anonymous reader shares an excerpt from Musk's keynote speech: Tesla CEO Elon Musk -- whose company makes electric cars and has a new solar roof panel division -- reminded more than 30 state governors at the National Governors Association meeting this weekend exactly how much real-estate is needed to make sure America can run totally on solar energy. "If you wanted to power the entire United States with solar panels, it would take a fairly small corner of Nevada or Texas or Utah; you only need about 100 miles by 100 miles of solar panels to power the entire United States," Musk said during his keynote conversation on Saturday at the event in Rhode Island. "The batteries you need to store the energy, so you have 24/7 power, is 1 mile by 1 mile. One square-mile." It's "a little square on the U.S. map, and then there's a little pixel inside there, and that's the size of the battery park that you need to support that. Real tiny."