PHOENIX—A team of students from Arizona State University and the University of New Mexico has collaborated to create a net-zero-energy home and hopes to garner a prize at a national competition.

The ASU/UNM team will compete this week against 19 other entries at the U.S. Department of Energy's Solar Decathlon in Irvine, Calif. The event is a Super Bowl of sorts for solar-powered homes and is aimed at creating a new generation of builders who think green, the Arizona Republic reported (

The event is held every two years since it takes that long to dream up, engineer and construct the sustainable homes, which are judged on performance, affordability and livability.

The ASU/UNM's 850-square-foot SHADE home has a radiant heating and cooling system that uses water-filled capillaries above a plaster ceiling as a way to cool or heat the home. SHADE is an acronym for Solar Homes Adapting for Desert Equilibrium.

"It's an effective system," said Alia Taqi, an ASU graduate student on the decathlon team. "It works really well in dry climates, and it's a little more costly than a traditional HVAC cooling system. But, in the long run, it uses almost 40 percent less energy."

The house cost about $285,000 to build and will produce all its own energy, saving an estimated $150 per month compared with a conventionally built home of the same size.


Net-zero homes tied to the grid pay only the minimum monthly fee to their utility company—about $10 to $17 per month for billing and meter reading.

The team is also testing material in the floors that absorbs energy when a room is warm and releases it when the temperature drops, evening out a room's thermal profile.

SHADE also is testing a thermal battery, which is used in some commercial buildings. It freezes water at night and uses ice during the day to cool a glycol and water solution carried to the cooling systems.


Information from: The Arizona Republic,