Homes shaped like a cocoon, a mound and a Y now stand in a park adjacent to the National Mall, looking for a ray of sunshine. Amidst the brouhaha surrounding the loan to solar-module manufacturer Solyndra, the latest "solar decathlon" competition begins today, September 23, in Washington, D.C.—leading to a cohort of 20 innovative solar homes standing in West Potomac Park.

Since 2002 the U.S. Department of Energy has put on such a competition every couple of years, aiming to train students in the art of solar building. The idea is to challenge the teams of college students to "design, build and operate solar-powered houses that are cost-effective, energy-efficient and attractive." Judge the latter for yourself in the following pictures.

View slide show of 2011 solar decathlon entrants

The rules of the competition are simple: design the kind of house described above and assemble it in Washington, D.C., for judging. Then juries of experts evaluate each entrant on architecture, appeal, engineering, communications (meaning how well the designers explain their house to others), affordability, comfort, hot water production, appliance efficiency, home entertainment (ecofriendly dinner parties and movie nights with your neighbors!), and, finally, how much energy the house actually produces. And you can participate, too, by helping vote for the "People's Choice Award."

The goal is to glean some of the bright ideas from these homes and embed them in the real world. The idea has proved so popular that similar competitions have spread to Europe (next event, spring 2012) and, most recently, China (mark your calendars for 2013).

For the past two U.S. decathlons, sunny Team Germany triumphed, making them the team to beat—except that they're aren't competing this time. That leaves the solar field wide open, especially because there is a spending limit to ensure that no one simply buys victory with the most expensive and efficient technology. The winner will be announced on October 4, but the true victors enjoying the solar spoils of this competition may be future home-owners.