You know what geothermal energy is -- heat from the Earth. Could a new twist on geothermal power help countries achieve energy independence? See more »

Plants produce energy so perfectly: converting sunlight, carbon dioxide and water into power and emitting nothing harmful in the process. Can we imitate such an elegant system? See more »

What if harnessing hydroelectric power didn't require building a large dam and an even bigger reservoir? Bourne Energy has plans for a device that harnesses the natural movement of water in rivers. See more »

Cellulosic ethanol can be made from any old stem, leaf or tree trunk. Farm wastes, grass clippings and recycled newspaper will work, too. So when can we expect this alternative fuel to arrive at gas stations? See more »

That's not just any mud. That's a fossil fuel that's stashed away in huge quantities in deposits all over the Earth's crust. Could that frozen fuel also heat up the planet? See more »

Gasification could represent a second chance for coal. Will this old technology, which can run on coal or biomass, get a new life as one of the most important energy alternatives of the future? See more »

Watch mountains of water crash along the coast, and you'll have no doubts about the ocean's awesome power and the energy potential it holds. Humans have been interested in harnessing that energy for centuries. See more »

There are two main ways of generating energy from the sun. But one -- solar thermal technology -- is really poised to take off as a clean, reliable form of alternative energy. See more »

The rising cost and projected scarcity of fossil fuels has people talking. But finding a new power source and developing an infrastructure will be costly and challenging. Will we still be using gasoline in 2050? See more »

Solar energy is clean and plentiful. There's one big problem, though: The sun doesn't shine all the time. Is there a way to keep solar plants powered up through the night? See more »