For the 2009 Solar Decathlon, the U.S. Department of Energy selected 20 college teams to compete in designing, building and operating the most attractive, energy-efficient, solar-powered, and net-zero energy homes.

Solar village entries compete in ten categories: architecture, engineering, graphics/communication, comfort zone, hot water, appliances, energy balance, lighting, marketing, and getting around.

“We’re expecting to sell energy back to that mini-grid on the Mall,” said Chris Werner, team leader for Cornell University. His team started designing its 800-square-foot home in 2008. They took design cues from grain silos outside Ithaca, New York, using three cylinders of Cor-Ten steel for a bedroom, a living room and a kitchen.

They mounted 40 GE solar panels, at 200 watts each, four feet above the roofline. Solar thermal provides hot water and heat; cooling is achieved with a reverse cycled chiller. A 16-foot-long accordion-fold window, called a NanaWall, opens up the living room to an outdoor courtyard. “The house doubles in size when it’s open,” Werner explained.

Ciick here to check the various teams' progress. All entries are open October 9-13, and October 15-18, 2009.

To see our coverage of the Decathlon from years past, click here and here.