The DOE’s biennial Solar Decathlon kicks off Sept. 23 for what may be its final year in Washington, D.C. Typically held on the National Mall, the DOE accepted proposals through the end of August for a 2013 host city and it may to move the event to various locations across the country every two years. This year’s competition, running through Oct. 2 at West Potomac Park, features varied and innovative solutions for solar-powered, efficient, portable housing designed and built by university students from around the globe. The 20 teams, whose designs can be seen in the accompanying slideshow, currently are assembling their houses in time for Friday’s opening. Team members will be on site during the day to answer questions for homeowners, educators, students, architects, builders, and other industry pros as well as the general public. In addition to house tours, the DOE provides educational resources, events, and workshops for visitors.

The first Solar Decathlon took place in 2002 and it has been held every other year since 2005. The primary intent is to inform visitors about solar energy and other environmentally responsible technologies, but it’s also a competition with stringent rules that requires a lot of planning, funding, and extra-curricular effort from the university students and their advisers. The teams’ official challenge is to “design, build, and operate solar-powered houses that are cost-effective, energy-efficient, and attractive. The winner of the competition is the team that best blends affordability, consumer appeal, and design excellence with optimal energy production and maximum efficiency.”

Each house is a fully functioning model and must meet strict building codes based on the International Residential Code (IRC) for one- and two-family dwellings. In addition to regular IRC requirements, the competition committee dictates other guidelines to deal with the distinct nature of the event. For example, all houses have to be ADA complaint to allow full visitor access. Entrants also have to construct a working solar envelope that demonstrates imaginative energy-saving technologies, such as the use of phase-change materials for storing and releasing energy, without causing any lasting impact to their sites. Although the DOE uses the standard building codes as a basis for its competition, DOE building inspector Tom Meyers explains that the event in turn affects the IRC. “We have looked at changing the building code based on what we see coming from student innovation here,” says Meyers, adding that “this is one of the big national benefits of the Solar Decathlon.”

Once the 2011 competition ends, each house will move to another location and, like past entries, will be used for education, community outreach, energy-monitoring, or housing. For example, one of this year’s homes will become a Habitat for Humanity house while others will be used as student housing, energy research space, or a touring lab for environmental preservation. New to the competition this year is an affordability category, and several of the entries will become homes for deserving families. A history of the Solar Decathlon, information on this year’s teams and event, or details on how to apply for future competitions can be found at