We've seen some pretty out there solar installations, but JAXA, the Japanese space agency, is about to get really far out with its latest project: a space-based solar array that beams power back to Earth.

If you can rent movies, video games and even handbags online, why not toys?

A seagoing glider that uses heat energy from the ocean to propel itself is the first "green" robot to explore the undersea environment, U.S. researchers said on Thursday.

California Gov. Arnold Schwarzenegger on Monday signed into law a bill that aims to make the state one of the world's biggest producers of solar energy. The bill, which cleared the state Senate last week, calls for the installation of 1 million rooftop solar panels on homes, businesses, farms, schools and public buildings by 2018.

In a historic boost for renewable energy, PG&E said Thursday it will increase its use of solar power nearly fivefold.

The East Japan Railway Company (JR-East), as part of research aimed at developing more environmentally friendly train stations, is testing an experimental system that produces electricity as people pass through ticket gates.

An MIT chemical engineer explains why new technologies could finally make "heat mining" practical nearly anywhere on earth.