California's Public Utilities and Energy Commissions' site has a solar contractors database, information on how to go solar for new homes and retrofits, news, pdf handbooks, and more. California Solar Initiative offers rebates for installing solar on home or business.
Information on renewables, nuclear, electricity, and fossil. Data on production and consumption. Solar links to SunShot, "a national initiative to make solar energy cost competitive." SunShot includes news, videos, how-to guides, and more.
Renewables and the science behind them: from photovoltaics and wind to geothermal and building efficiencies. Links to concentrating solar power includes short videos. Photovoltaics includes links to engineering aspects.
One-stop shopping from the U.S. Dept of Energy for state, federal, local, and utility incentives that support renewable energy and energy efficiency. Click a state on the homepage map for links to incentives for solar water heaters, solar-heated homes, green buildings, and more.
Bertrand Piccard, who circumnavigated the Earth in a hot-air balloon, talks about doing the same in a solar-powered aircraft (18 min.). Piccard's biography. New York Times article on his solar-powered plane.