Solar City University Competition

Some 800 students from 20 schools will be represented in Washington, D.C. over the next ten days to compete in an alternative energy competition to design an off-grid, zero-emission house.

Team California, a partnership between Santa Clara University and the California College of the Arts, assembles its home on Oct. 7. The bent design takes advantage of south-facing vistas, making it seem larger. Each team got $100,000 from the Energy Department to design its home over the last two years, then transport it and assemble it on the National Mall. The department, for its part, hopes to get a payback over time: research that leads to reduced costs for solar technology.

Virginia Tech's entry includes metallic sun screens that open to reveal glass walls and a bio-filter system that uses plants to clean up graywater from the bathroom and clothes washer. Energy Secretary Steven Chu said he expected the competition to lead to cleaner and more efficient use of energy. "Homes and other buildings account for 40 percent of the energy we use in the United States — more than we use in transportation or industry," he said in a statement. "Competitions like this one can lead to new solutions and inspire a new generation of problem solvers."

The University of Louisiana at Lafayette had its solar-powered home up and running on Wednesday. Dubbed BeauSoleil, it includes a porch skylight that partially shades the south side, creating a solar thermal system that heats the house's water. The exterior cladding allows air to circulate between the siding and the wall to minimize heat gain. Walls are made of 6.5-inch insulated panels, providing double the insulation of stud walls and reinforcing the building.

Team Germany's entry is essentially a two-story cube. The outside walls and roof are covered with thin-film solar panels and photovoltaic cells. The team from Darmstadt Technical University expects to produce twice the energy needed to run the house. The team ran two 12-hour shifts on Monday to assemble the house, then installed the wiring the next day. On Wednesday, the house was plugged in and able to send excess energy out onto the electricity grid.