The Solar Decathlon, a popular competition and expo organized by the Department of Energy (DOE) that invites teams to build houses powered by the sun, opened to the public today in Washington, D.C., though the dwellings aren’t on display in the highly visible location many participants sought. Moreover, this likely is the last year the event, launched in 2002, will be held in the nation’s capital at all.

In the four previous Decathlons, the houses were set up on the National Mall near the Washington Monument, where they could be viewed by tourists, who frequently visit that area, and lawmakers, who might also pass by.

This year, in a departure, the 19 dwellings, designed by teams affiliated with universities from the U.S. and abroad, are set up in West Potomac Park—an eight-acre site dotted with baseball fields that is technically part of the Mall but located by the Tidal Basin, farther from foot traffic. The houses will be there until October 2. Judges will assess the buildings in 10 categories—hence, “decathlon”—related to design, cost, and efficiency. The winner will be announced October 1.

The expo was relocated this year because the National Park Service (NPS), which oversees the Mall, decided last January that the construction process required to assemble the temporary dwellings, and subsequent crowds, generated too much wear and tear on the site’s grass.

That decision threw the Decathlon into disarray. Organizers, who already had whittled 40 initial entries to 20, scrambled to find another site. Plus, participants worried that their sponsors, who shoulder most of the construction costs, would be unhappy with a lower-profile location.

In 2009, the event drew about 100,000 visitors, says Decathlon director Richard King of the DOE. Despite the location change, he’s expecting the same attendance numbers this year, in part because the DOE will run shuttle buses every 10 minutes to the park from the closest Metro subway station. It’s important to pull in visitors, King says, as the event can positively influence people’s opinions about sustainable design. “You need to have an educated public to make this industry grow,” he notes.  

Faced with the trouble of finding a location that’s not on the Mall—West Potomac Park is just at temporary solution—and palatable to participants, the DOE is likely to relocate the event in 2013 to another city entirely, King says.

In the meantime, many contestants are just happy that this year’s Decathlon wasn’t canceled outright, like the 85-member team from Middlebury College, which is participating for the first time. Not one of its sponsors, which include Stonyfield Organic, Bosch, and Kohler, dropped out because of the relocation, says Joseph Baisch, the team’s lead architect.

“It was kind of disappointing at first when it moved,” he says. “But now it seems pretty accessible.” And whatever the competition’s outcome, the team’s efforts this year will have pay off. Meant to evoke a New England farmhouse and featuring a gabled roof lined with 30 solar panels, their “Self-Reliance” house, named after a Ralph Waldo Emerson poem, will end up as housing for students on Middlebury’s campus.