Solar roofing panels don't have to be hideous, as evidenced by U.K.-based Solar Century's C21 photovoltaic roof tiles. Except for a slight bluish tint, they look like a traditional roofing slate. And unlike most other solar panels, the electric links between tiles are so simple that any roofer--not just a solar panel specialist--can handle the job. Enough tiles to provide half the power for a 1,400 square-foot home cost about $14,000. The break-even point is a decade or two.