This week in Washington, D.C., 20 teams of college students will build solar-powered houses on the national mall, and will compete to determine which dwelling uses the least energy. One of those teams comes from California. KPCC's Molly Peterson has more about its project.
Team California calls its structure Refract House. The name refers to the house's shape – a narrow tube bent around a deck. Twenty-one-year old Preet Anand points to some renderings of the house, which curls around a wood deck. "That deck is on the south side of the home," the college senior says. Refract House also refers to the light and heat of the sun. "There's a lot of sunlight coming into the house because the sun is in the south."
Anand and other students from Santa Clara University, along with California College of the Arts have developed and built a house powered by the sun. Anand says the house uses solar photovoltaic panels and solar thermal collectors on the roof. Inside, passive heating and cooling conserves energy. "We use radiant floors and radiant ceilings instead of blowing an air vent to blow hot air or cold around. The floors and ceilings themselves radiate energy or absorb energy to cool and heat the space."
Instead of using the mainstream product Tyvek to wrap the house, Team California recycled weatherproof billboard ads to do the same thing. Vegetable-oil based insulation lines the house. Anand says that as Californians, he and his teammates are conscious of saving water, so they recycle water for irrigation, and design ways to reduce waste.
One is a recirculation pump system, which Anand says your house could have for $600. "Say your shower's pumping two gallons a minute. And for five minutes you walk away because you're waiting for the water to get hot. You just wasted 10 gallons of fresh water. But if instead you can take a shower right then and there, you're saving that water and you're saving that time."
Team California took eight days to truck its house on flatbeds to the nation's capital. That got factored into the design – the framing is steel, to withstand a bumpy road. The student-run project competes in 10 categories, from market viability to engineering, with an overall winner at the end.
The federal Department of Energy will meter each house to determine how much energy it uses and produces. Anand says power meters will spin forward and backward, as the house draws energy from the sun, and uses it. "You're watching TV at night. But if your solar panels are doing all their production during the day, you're giving to the grid then and you're taking from the grid at night. So how much more are you giving to the grid than you're taking from the grid? That's net metering."
Net metering's gotten more attention lately in California, where law limits how much utilities accept to 2.5 percent of its power. Proponents of rooftop solar want that cap lifted entirely or raised. A bill that would expand the program is stalled in the state legislature.
Student Preet Anand says his team also learned about other hurdles for green building. Local building codes can be slow to embrace new technology; Team California's greywater system has a special demonstration permit in its hometown of San Jose. Anand says the state could further encourage green building with more incentives. "Green building is just making a conscious choice to save energy, to save water, and to save materials," he says. "And however you can do that that is what green energy is."
Team California's off to a strong start – it’s the first team to pass electrical inspection on-site. Judging and public tours start later this week.