Solar gets competitive at the decathlon

The National Mall in Washington, D.C., became much more homey today with the opening of the third Solar Decathlon.

Teams from 20 universities in the U.S., Germany, Spain, Canada and Puerto Rico put out the welcome mat for visitors to their model, solar-power houses.

Backed by the U.S. Department of Energy, each team is trying to build the most efficient solar-powered home, with all the comforts, and appliances, packed into approximately 800 square feet.

The teams have been working on their homes for the past two years, with each group getting $100,000 in funding from the DOE for the project.

"The houses cost anywhere from roughly $500,000 to $1 million to build and transport here, so we give them kind of a head start," Kevin Brosnahan, spokesman for the DOE, told the Cleantech Group.

Check out the Georgia Institute of Technology team >>

While solar is definitely the focus of the competition, there are 10 different categories in the competition, and there have been some significant advances in other parts of cleantech to come out of the program.

"In 2005, Washington State University was a participant, and they applied for a patent for an engineered decking material," said Brosnahan. They used a wood-plastic composite, developed at WSU's Wood Materials and Engineering Laboratory.

This year, Santa Clara University is using bamboo I-joists, made with compressed bamboo, and they're also applying for a patent.

SCU said this is the first time bamboo has been used as a structurally load-bearing material in the U.S. According to the university, the I-joists can support up to 10,390 pounds before bending or breaking.

The architecture portion of the competition accounts for more points than any other part of the contest, and SCU could do well for using a sustainable material, since bamboo replenishes itself in 5 to 7 years, compared to the 30 to 50 years needed by hardwood.

Corporate sponsors like Sprint Nextel have also come out ahead with innovations for the decathlon. "In 2005, they networked all of the wireless sensors that evaluate and measure what's going on in the homes," said Brosnahan. He said the company received five patents based on the system they designed.

Getting an early lead in this year's decathlon is the University of Texas at Austin. UT took the early prize this week for being the first to complete their solar home. The university is using 6 inch structurally insulated panels in its design with an R-24 value to reduce heating and cooling needs.

"Most of the teams build the houses on their campus first, and then disassemble them, transport them to the National Mall, and reassemble them," said Brosnahan.

The students and their deconstructed homes arrived in the capital at 12:01 a.m. EDT on Oct. 3, and the teams have been working around the clock to get things ready for the week-long decathlon.

The University of Colorado is the one to beat. The university already holds trophies from the 2002 and 2005 competitions. The team's design for 2007 is based on a modular and prefabricated engineering spine, formed by conventional shipping containers.

In addition to building and powering an efficient home, the teams also have to use their precious solar energy to feed a GEM electric car. And they can't just fill it up, they have to drive it around, too, or they lose points.

The GEM e4 cars are from Global Electric Motorcars, a Chrysler company. They're street legal, but they only have a top speed of about 35 miles per hour, and they look like golf carts.

While the judging of the architecture could be subjective, most of the competition measures the overall performance of the home.

"The other contests are mostly objective in that they're measured. Temperature control, and overall electricity usage," said Brosnahan.

"They have an appliance contest where they have to do dishes, and then do cooking. They have to do laundry, and wash and dry towels. Run computers and CD players."

And what do the students get out of all of this work? Fortune and glory? Well, glory, certainly.

"There's a trophy but there's not an actual cash prize. I think most of the students would probably tell you the prize is the job experience and the jobs they get after it," said Brosnahan.

He said the professors, who are the technical leads and advisers for the teams, also appreciate the opportunity to get their hands dirty. "All of them have talked about this and designed these all their whole life, and very few have built them."

The winning team will be announced on Oct. 19.

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