Summer's just 2 months away, and what better way to keep cool than with SolCool's solar-powered air conditioner, the Millenia. Theoretically, it makes sense. Not only will it help cut down your electric bill, but it'll keep you cool even when the lights go out. And should the blackout occur at night, the AC can run off back-up batteries that last for up to 24 hours. The unit is set to come out next month for just under $3,000 (plus $500 installation). Now if only they could team up with LG to get rid of the AC's recycle bin look.

Using Solar Energy to Keep Homes Cool []