Here's another solar powered hosting/datacenter service, this one is a little diferent in that they are completely powered by the sun. Compared to other plans they are fairly pricey - $25 for 50MB and 1 GB data transfer - but the price is comparatively low. I'm considering moving New View over here. It's a really neat idea, a great marketing tool for any site involved in new technologies.
Here's another article on the company.