By Steven Mufson
Washington Post Staff Writer
Friday, October 12, 2007
In front of the Smithsonian Castle, the Mall has taken on the appearance of "Extreme Makeover: Home Edition" meets Extreme Climate Change.
Over the past week, teams of university students have hammered and drilled together 20 small, energy-efficient homes with choice views of the Capitol in hopes of winning the top prize in the Energy Department's third Solar Decathlon, which starts today.
The design contest is a showcase for photovoltaic panels, inverters and insulation as well as hot tubs, skylights, carports and hanging gardens.
"A lot of students don't get the opportunity to build what they're designing," said Kim Singleton, an architecture student at the University of Maryland, which has dubbed its abode the LEAFHouse, as in Leading Everyone to an Abundant Future. "Plus," she said, "designing green is the up and coming thing."
That wasn't the case when Richard King, an Energy Department engineer, thought of the decathlon, which gives a trophy to the winner. King said he sought to tap "the power of our engineers" and figure out how to "design a solar house that is aesthetically pleasing." With growing concern about climate change, there is a greater sense of urgency about making solar, which accounts for less than 1 percent of U.S. energy needs, more practical and economical.
"It's never been this close," Energy Secretary Samuel W. Bodman said about solar's prospects. Solar costs less than peak electricity in much of the country, but costs need to be cut by half before the technology can compete with conventional fuels without subsidies.
Even with a lot of free labor, custom features and first-time costs brought the tab for most of the structures to $500,000 to $1 million each, paid for with Energy Department grants and individual and corporate donations.
The homes, which can be no larger than 700 square feet, are scored on 10 measures of appearance, marketability, and performance of daily household chores while maintaining comfortable temperatures and charging a battery-driven car.
Passing those tests can be tough. In 2005, several days of rain and clouds took a toll on solar-powered batteries. As to the designs, some energy-miser homes in past years have had all the pizazz of Jimmy Carter in a sweater.
This year's teams came equipped with extra batteries. Texas A&M University brought 6,000 pounds of batteries. The designs, although imaginative, are variations of one-story boxes -- low enough to maximize roof space for solar panels and rectangular to get them to the District in trucks or containers.
The team to beat is the University of Colorado at Boulder, winner of the decathlons in 2002 and 2005. This year, it built its house around a "core" with the essential heating, air-conditioning, plumbing and electrical systems. The core, designed to power a full-size home, could be mass-produced with custom floor plans and fixtures around it.
The 2005 runner-up, Cornell University, has designed a light steel canopy for the solar panel array, solar thermal tubes and vertical vegetation. The canopy is made of inexpensive scaffolding and is painted and decorated with plants. It can be built around an existing home. "The solar market is constantly changing, and you can upgrade systems without damaging the house," said Siobhan Rockcastle, a Cornell architecture student. Kids who saw it in Ithaca, N.Y., thought it was a jungle gym.
Environmental matters governed Cornell's choice of materials. The porch floor is a composite of wood and recycled plastic fibers. The ceiling wood was made from an old silo. The siding is sustainably harvested white cedar.
The secret to success in the decathlon isn't just the energy generated by solar panels; it's finding ways to slash energy use. The Cornell kitchen, for example, features refrigerators that open like drawers so that cold air, which falls, does not escape easily when the door is opened. At the University of Maryland's LEAFHouse -- "A leaf is the ultimate solar collector," said Brittany Williams, an architecture major -- a wall of plants on the south side provides a sunshield and filters water for reuse. Texas A&M has quadruple-pane, argon-filled windows. Fluorescent bulbs and LEDs are standard.
Turning an appliance into decoration, an indoor waterfall doubles as a dehumidifier at the U-Md. house. About 30 percent of the energy used by home air conditioning goes to reducing humidity. The waterfall uses a mixture of calcium chloride, an absorbent salt, to suck moisture from the air. If any of the liquid mix spills, it absorbs humidity and the puddle grows. The liquid tumbles down a clear decorative panel with an opening for air, then drains to a device outside where the excess moisture evaporates before the remaining liquid is pumped back into the house.
Some homes have frivolous touches. The University of Texas home siphons excess heat into a hot tub. The team sheathed the home in aluminum bus siding plastered with a blown up image of a cactus flower.
Foreign universities are also competing. A handsome structure with louvers made of oak and photovoltaic cells has been built by the Darmstadt University of Technology. It features sleek appliances from Germany, where energy efficiency and renewable energy are higher priorities than in the United States.
U.S. use of solar remains tiny despite generous subsidies and industry growth rates approaching 40 percent a year. Climate change concerns are driving new initiatives to limit the use of coal, which accounts for half of the country's electricity. Since the last solar decathlon, more states have tried to kick-start solar construction. California has begun an 11-year, $3.35 billion subsidy program aimed at installing solar panels on 1 million homes, and its utilities are planning large-scale solar generating installations.
Climate change ironies about the decathlon weren't lost on the students. Colorado used three flatbed diesel trucks to get its home to the Mall. Cornell's trucks had to follow a roundabout route to take bridges strong enough to bear the weight of the equipment, turning a 350-mile trip into a 600-mile one and adding to the fuel burned to get to the District.
"Hopefully, the impact we have by being on the National Mall will offset the diesel it took to get here," said Chad Corbin, a graduate student in engineering at the University of Colorado.
The Solar Decathlon is open to the public until Oct. 20, from 11 a.m. to 3 p.m. weekdays and from 10 a.m. to 5 p.m. weekends. It is closed Wednesday for judging. More information is available athttp://www.solardecathlon.org.