....solar power has been around for a generation now...right here on earth....if it was so good and so cheap the free market would have cashed in by now....every new house in Phoenix would have a roof top unit built right in.
Don't look now, but that is about to happen. Nanosolar's "line printed" CIGS cells (14-15% efficient) will drop the price to $1/watt or less. They're already selling cells to "utility size" installations, and their next production plant is aimed precisely to the "roof-top solar" house market.