The University of Maryland won this year's Solar Decathlon competition by engineering a net zero-energy house and making water conservation central to its form and function.
The Department of Energy announced Saturday that Maryland won the DOE-sponsored university competition to build the most compelling solar-powered house. Each of the 20 team participants is judged on 10 different factors, including architecture, affordability, and market appeal. (See Solar Decathlon coverage from and .)
In a speech on Saturday, Energy Secretary Steven Chu congratulated student participants, telling them they are aiding the U.S. in a global competition to develop clean-energy technology industries.
With the WaterShed house, University of Maryland students chose to make the ecosystem of Chesapeake Bay a guiding theme for their house which was assembled and displayed in Washington, D.C., last week alongside the houses of other participants.
The building has a butterfly design where slanted roofs on two halves of the house direct rainwater into a "constructed wetlands" built in and around the house. Native plants filter storm water and gray water from the showers and sinks and store it in a cistern to irrigate plants or the vegetable garden.
Water also helped the energy efficiency of the house. The building had a Liquid Dessicant Waterfall, invented by the 2007 University or Maryland team, where a high-saline solution flows down an indoor water column to absorb water out of the air. Removing that humidity lowers the energy load for the building's air conditioning units. A green roof helps insulate the building as well.
Although inspired by nature's cycles, the house is high-tech, using both solar photovoltaic and solar hot-water panels to use less energy as it produced during an occasionally rainy week last week. It also has a home automation system which optimizes the heating and cooling and lets residents control house functions from a network device, such as a tablet computer.
Other competitors in the Solar Decathlon pursued many of the same goals as the University of Maryland and used the same techniques, including modular buildings, home automation, and efficient lights and appliances. For example, the second-place team from Purdue University built in a "biowall" of plants to clean indoor air and third-place Team New Zealand also used a butterfly design to collect rainwater.
Chu: We must invest in clean energy
Recently, the Obama administration has been on the defensive about its policy of providing loans for energy companies and projects in the wake of solar company .
"Others say this is a race America shouldn't even be in," Chu said during his speech. "They say we can't afford to invest in clean energy. I say we can't afford not to. It's not enough for our country to invent clean-energy technologies--we have to make them and use them too."
He also defended the loan guarantees given out as part of the 2009 stimulus program, which were used to finance renewable-energy projects, a nuclear power plant project, battery and solar-panel factories. Thegenerated 60,000 direct jobs and will result in enough renewable electricity to power two and a half million homes, he said.