Reaching for sun power

I get so excited about new breakthroughs in renewable energy (I know, I'm kind of a nerd that way), so I thought this news bit very cool. Basically, converting sunlight into power was only about 8% efficient, but new technology has shot that up to 40%. At that rate, 265 square miles of American southwest desert fitted with solar panels would supply enough to power THE ENTIRE WORLD. There are setbacks to this idea of course (e.g., how to get that power to the entire world, the economic and environmental impacts of this change), but the advances are very exciting. Imagine a world with no more coal plants! Imagine every home with solar panels on the roof supplying energy for the home, no pollutants burning into the atmosphere. It seems like a real possibility in our lifetime. I love it when the present day catches up with my childhood idea of what the future would be like. But as my husband often laments, there still aren't enough household robots doing our bidding.