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Many hands make light work: Cornell's solar house vying for top prize in Washington

Two years after placing second in international competition, Cornell's Solar Decathlon team is almost ready to take its new solar house to Washington, D.C.

The fully integrated, totally self-sustaining Cornell house is certain to stand out from 19 other schools' entries during the biennial competition Oct. 11-19, sponsored by the U.S. Department of Energy. The house's major innovation is a canopy made of steel scaffolding surrounding the structure.

"We're limited to 800 square feet [inside], so the canopy is a way to extend the feel of the house to the outside," said Bryan Wolin '08, the team's communications director, who has spent all but one semester at Cornell working on the decathlon.

The planning, design and engineering of the house over the past two years has culminated in construction and assembly over several weeks at the former High Voltage Lab near campus on Mitchell Street. The team leaves for the National Mall Oct. 1.

"The canopy is really a metaphor for how we designed this house collaboratively," said Bernardo Menezes '08, a team leader.

The effort involves students from all seven undergraduate colleges at Cornell, plus the Johnson School and the Graduate School. About 40 percent are engineers and 25 percent are architects. Students from ILR and Arts and Sciences worked on the business team, raising money for the $600,000-plus project. All of the house's electronic sensors were designed by a neurobiology student.

"You plug something in and can see how much current it's using," Menezes said. "You can activate it externally -- you take out your cell phone and text your house."

The "light canopy" will be fitted with 69 photovoltaic panels, feeding electricity to all operating systems and to storage batteries. Glass tubes filled with propylene glycol (used in antifreeze) and a Pennsylvania bluestone floor will collect passive solar heat inside the house. The glycol solution will warm the contents of two 80-gallon hot water tanks, which also help heat the house. Folding glass "nanowalls" on the south side of the house and lightweight, interlocking structurally insulated panels will provide thermal integrity, even in a harsh upstate winter.

Other energy-saving features include LED and fluorescent lights that use sensors to automatically adjust to outside light; current-detecting sensors on electrical outlets; an induction stove to heat ferrous metal pots quickly, using spinning magnets; and a refrigerator retrofitted from a chest freezer which, unlike a conventional appliance, keeps the cold air inside when opened.

All of the house's inner workings can be controlled either remotely or with a 19-inch touch-screen panel, which "provides all the information any homeowner could want about the heat and light system of the house," Wolin said. "You can control it and see how well the systems are working."

To save space, the bedroom doubles as a work room/office, with a fold-up Murphy bed. Homey touches include recycled barn board and picture frames. A Corian dining table and matching countertop feature interchangeable flat and scooped inserts for growing herbs.

"Our landscaping has played a role in everything, down to what table we ordered," said Jennifer Ng '08, a landscape architecture major. "This time we're taking the landscape and integrating it into the house more [than we did two years ago]."

The water-sealed bathroom's shower drains under the house, feeding a constructed wetland and watering trees, tall grasses, vegetables and other plants. Each team in the competition must host a dinner party; the Cornell house's garden will supply the vegetables, which a Taverna Banfi chef and culinary students will prepare.

Teams also must rack up miles on a provided electric car (also powered by the house) and give public tours.

For more information on the Solar Decathlon effort, visit

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