The race to win GE's "Powering Your Home" Ecomagination Challenge [2], a contest that invites entrants to design the green home of the future, is on. So far, all the entrants are impressive, but one stands out: a proposal for transit tunnels that power cities.

Submitted by Alessandra Rapaccini and Giacomo Sanna, the CitySpeed Turbine [3] turns transit tunnels into modular turbines that harness wind power from passing vehicles. The potential for energy is impressive--according to the NY/NJ Port Authority, approximately 202,000 cars pass through the Lincoln and Holland Tunnels each day. Combine that with train tunnels, and the device could be a significant energy source.

We aren't entirely sure how the CitySpeed Turbine fits into the "Powering Your Home" theme, but it's still one of the better--and more popular--entries in the contest. Other favorites include the Sunnovations solar hot water system, Clarian plug-in backup power and storage, and the high-performance seasonal cool roof.

Ariel Schwartz can be reached on Twitter [4] or by email [5].