By Stephani L. Miller. Late last year, the U.S. Department of Energy sponsored a Solar Decathlon, an event that pitted 14 teams of architecture and engineering students against each other to see which could design, build, and operate the most energy-efficient and aesthetically designed house powered entirely by solar energy. For two weeks during September and October 2002, the National Mall in Washington, D.C., hosted the Solar Village, where the teams' houses were evaluated by industry experts and toured by the public.

To maximize energy efficiency, the teams focused not only on design and aesthetics but also on building products. The winning team, from the University of Colorado at Boulder, evaluated potential building products -- from framing timbers and foundations to windows and photovoltaic panels -- according to nine criteria. Each product had to incorporate at least three of the following elements: reflect a sustainably harvested or an environmentally friendly manufacturing process; possess low embodied energy; include recycled, recyclable, value-added, nontoxic, or low-VOC features; and be made in the United States.

The Colorado team found that at least one currently available, off-the-shelf building material in almost every category met its requirements, including photovoltaic panels by AstroPower, SUNTube solar thermal evacuated tubes by Sun Utility Network, heat-reducing Primalite glazing, and HeatMirror insulating glass by Southwall Technologies. The team also found that these materials are priced comparably to conventional building materials while providing improved efficiency.

Other teams found solar technology products to suit their requirements as well. For example, the Crowder College team installed solar cell panels from BP Solar, and the University of Virginia team used photovoltaic panels from ASE Americas.

Over the past four years, the demand for solar panels has increased by 20% each year, according to the DOE.

"Energy is presently a high-cost item," says Les Hamasaki, executive vice president and sustainable development planner for Sun Utility Network. Solar energy "is the only source of energy that is provided free," he says.