Could roads that collect and distribute the electricity from the sun be the clean energy source of the future? How about portable, miniature fueling stations that turn just about any organic waste into fuel for vehicles? As far-fetched as they may sound, both ideas already being prototyped in labs and are going head to head with thousands of other inventions to be tomorrow’s clean energy solution.

While still in its nascent stages, the development of commercial alternatives to fossil fuels recently got a huge shot in the arm in the form of a contest sponsored by General Electric, the Ecomagination Challenge. The GE Ecomagination Challenge is a competition at the frontier of a new global energy future. Inventors, tinkerers and dreamers from around the world have been invited to submit their best ideas to power a world of scarce petroleum in exchange for the chance to net part of a $200 million prize.

Crowdsourcing energy innovation is a trend that is growing in popularity. The winner of the Progressive Automotive X Prize were recently awarded $10 million for their concept vehicles that could travel 100 miles on a single gallon of gas. Although vehicle performance tests were conducted on a closed race track, it’s possible we may one day see them on the road in some form.

The Ecomagination Challenge has three components, renewable energy solutions, energy grid efficiency, and solutions for homes and buildings that use energy in smarter ways. GE has partnered with Emerald Technology Ventures, Foundation Capital, KPCB and Rockport Capital to ensure that that winning plans get the money they need to succeed. While the move helps raise the profile of GE in the sustainability arena, the winning ideas could end up being huge moneymakers if they find a viable market.

We’ve profiled the eight best clean energy ideas submitted to the GE Ecomagination Challenge, and handicapped their chances of becoming gamechangers.