Cornell Solar Decathlon team erects its house under pressure in D.C. as competition looms

News
October 12, 2007

WASHINGTON, D.C. -- Two years of design work, fundraising, planning, and construction have come down to the wire for Cornell's Solar Decathlon team.

On October 10, with fewer than 48 hours to go before the international competition begins, the Cornell students, who arrived in the nation's capital October 3, scrambled to finish outfitting their energy-efficient solar house on the National Mall.

The biennial contest, sponsored by the U.S. Department of Energy, runs October 12-20, and 20 houses will be judged in 10 categories, from lighting, hot water, and appliance usage to architecture, engineering, and public presentation. Cornell placed second in the previous competition in 2005.

Integrating each of the houses' subsystems into one functional energy-efficient system is a challenge common to the decathlon teams.

"Everything we planned changed as soon as we got here," said Jennifer Ng '08, a Cornell landscape architecture major. "Everything that took months to design changed in a matter of hours."

For the Cornell team, that has meant sleep deprivation; driving back to Ithaca for more plants and materials; academic obligations; and "lots of phone calls, lots of scrambles, lots of last-minute, three-hour Home Depot trips," Ng said. "But now everything's coming together, and it's beautiful."

More than 100 students from all seven undergraduate colleges and two graduate programs at Cornell have worked on the decathlon team, and more than a third of them have been in Washington, busily preparing for the competition.

The activity level was similar all around, as other teams worked on their entries while construction vehicles and trucks came in and out of the Solar Village, on the west end of the mall near the Washington Monument. Teams from institutions across the continental United States, as well as Puerto Rico, Germany, Spain, and Canada, were invited to compete this year.

Cornell's 2007 entry is distinguishable on first sight by the house's surrounding "light canopy" of steel scaffolding, covered in photovoltaic solar panels.

"You could attach this canopy to any kind of house -- it shows how houses can adapt to solar energy without changing the existing structure of the house," said Alexandra Hollinger '06, a veteran of the 2005 competition who was pitching in along with a few other alumni.

Another eye-catching feature is the landscaping of more than 1,800 wetland and ornamental plants, trees, vegetables, and herbs nearly surrounding the house.

"The idea behind this extensive landscape is to connect the indoors to the outdoors," said landscape architecture student Bonnie Kirn '08.

Recycled gray water from the shower, sinks, and appliances inside the house drains outside to help irrigate the plants, including hops in planters clipped to the scaffolding and growing up wire "greenscreens," providing shade around the house's deck. "It's just one of the options, showing the potential that you have using the canopy structure," Kirn said.

"The landscape is one of the strongest things we have -- it makes the house stand out," said Hollinger, now a law student at George Washington University, as she worked on a tree planter box.

A solarium and dining area opens up via folding glass doors known as "NanaWalls," further connecting inside and outside. "It's really expressive of our design goals," Kirn said.

Other innovative features of Cornell's house include exterior-mounted evacuation tubes to heat a propylene glycol solution for twin hot-water tanks and interior heating, a touch screen to control the house's systems, a small combination washer-dryer and an efficient induction stove.

Apart from the solar panels and the long glass evacuation tubes, however, the appearance of the house from the outside isn't too dissimilar from a small mobile home.

"We didn't want to get too far out," said team member Bryan Wolin '08, a communication major who also participated in the 2005 effort. "You can see the other houses with different angles and color schemes. We were going for something more conventional; easy on the eyes and the environment."

The houses in the Solar Village will be open to the public Oct. 12-20, except for Oct. 17, when they are closed for judging. The winner will be announced Oct. 19. 

by Dan Aloi