Last year, Elon Musk promised to fix South Australia's power problems with a giant rechargeable battery. This year, he's building that battery which will count as the world's largest once installed. Now Musk is turning his attention to the US and believes it's easily possible to power all of the US using solar power.

At the National Governors Association meeting in Rhode Island, Musk explained his solution to powering the entire United States with solar panels, and it sounds surprisingly simple. All Musk would require is two plots of land. The first would be 100 miles square and filled with solar panels. The second would be one square mile and filled with batteries.

100 miles square, as Musk pointed out, is "a fairly small corner of Nevada or Texas or Utah."

Of course, putting aside a piece of land that big isn't going to happen. Also, it doesn't make sense to rely on one location for all power needs as it would instantly become a target. However, it does show how little is required to fully embrace renewable energy.

So instead of a giant plot of land, the same could be achieved with rooftop solar and utility-scale solar plants spread across the US. Of course, Musk would love for all those solar panels and batteries to be Tesla/SolarCity branded, and I suspect many of them will, but it's certainly going to be a growth market as renewable continue to get cheaper.

Musk also points to wind, geothermal, hydropower, and nuclear as transition power sources during the move to solar. And then that leaves gasoline and diesel-dependent vehicles, which Tesla is already working on replacing with electric vehicles.