Solar Decathlon finale becomes a ‘waterShed’ event

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Appropriately enough, when the clouds finally parted on October 1, the WaterShed solar home built by the University of Maryland team had taken top honors; followed by Purdue University’s INhome, in second place; and First Light, from the Victoria University of Wellington–New Zealand, in third.

All three teams had designed net -zero homes, which create at least as much energy from solar panels as they use from the grid. All excess electricity is pushed onto the municipal power grid, from which they can draw power when the sun isn’t shining, such as on rainy days and at night.

U.S. Energy Secretary Steven Chu announced the winners—and defended America’s solar policy—at the National Mall’s West Potomac Park. "Just as there is a fierce competition happening here, there is also a fierce competition happening around the world," Chu said. "The United States faces a choice: Will we sit on the sidelines and fall behind, or will we play to win the clean energy race?"

Chu asserted that the Department of Energy (DOE) had made an “historic investment” in renewable energy technologies through Section 1705 of the Energy Policy Act of 2005— a controversial program that has been widely second-guessed since Solyndra, the recipient of a $500 million loan, declared bankruptcy in late August.

"In past times of national stress, we took the long view and invested in our future," Chu said."We need to take the long view and invest in the future. That’s what made America great, and that’s how we will prevail."

The Solar Decathlon, he stated, not only demonstrated what could be done with renewable energy, but would inspire both entrants and visitors to rededicate themselves to creating a cleaner environment and buying energy-saving solutions."This competition to build innovative, highly energy-efficient homes has been two years in the making, and all of these teams must be commended for their hard work," Chu said. "The houses on display blend affordability, consumer appeal, and design excellence with optimal energy production and maximum efficiency."

The first Solar Decathlon was held in 2002; the competition has since been held biennially in 2005, 2007, and 2009, and 2011. The teams at each Decathlon build solar homes on the Washington Mall, each of which must:

• Be affordable, attractive, and easy to live in;

• Provide comfortable and healthy indoor environmental conditions;

• Supply energy to household appliances for cooking, cleaning, and entertainment;

• Furnish adequate hot water; and

• Produce as much or more energy than it consumes.

Throughout this year’s competition, 14 industry professionals juried five competitions in affordability, architecture, engineering, marketing, and communications. They assigned up to 100 points to each team for the competitions. The other half of the 1,000 total points was awarded for energy balance, energy measurements, and student tasks.

The teams—which hailed from the United States, Belgium, Canada, China, and New Zealand—performed everyday tasks, including cooking, laundry, and washing dishes, that tested the energy efficiency of their houses. Although the students didn’t stay in the homes, they certainly could have. Each team cooked two meals on two different nights for their Solar Village neighbors—competing decathletes who assigned points to the hosts for the meal. Another evening, they had a movie night, a demonstration of the 100-point home entertainment category. In this way, the creature comforts were weighted as heavily as engineering and architecture.

Maryland was the winner of three major categories, taking first prize in architecture, energy balance, and hot water.

This is not the first time that the University of Maryland competed and placed in the contest. "Maryland is a well-experienced team. After taking second place in 2007, they rested and regrouped in 2009 and came to West Potomac Park in 2011 focused and determined to win," said DOE’s Solar Decathlon Director Richard King.

"In addition, Maryland’s WaterShed is a beautiful house, judged first place in architecture, which also performed impeccably in measured contests. This team mastered their strategies to ensure they excelled."

The team’s key goal was to build a structure that had traditional "curb appeal" and did not appear to be a solar home. Except for the well-integrated 5.76-killowatt photovoltaic (PV) solar array from Madrid-based BP Solar on the back roof, the WaterShed looks like it would fit right into any conventional housing development.

Inspired by Maryland’s Chesapeake Bay, the power of WaterShed’s design comes from its twin focus on efficient, renewable energy, and water quality and conservation. The home’s holistic approach to water conservation, recycling, and storm water management includes:

• A modular constructed wetland that helps filter and recycle greywater from the shower, clothes washer, and dishwasher;

• A green roof that slows rainwater runoff to the landscape, while improving the house’s energy efficiency;

• A garden, an edible wall system, and a composting station to illustrate the potential for improved health, energy, and cost savings with a complete carbon cycle program;

• A patent-pending indoor, liquid desiccant waterfall for high-efficiency humidity control; and

• An efficient, cost-effective, durable, and time-tested structural system.

"Taken together, these design features make WaterShed ‘less thirsty’ for fossil fuels than standard homes and less dependent on costly water purifying infrastructure," explained team members Allison Wilson and Leah Davies. "The house acts as a micro-ecosystem that encourages residents to live a more sustainable lifestyle—not only by conserving but also by capturing and reusing natural resources."

Among WaterShed’s innovations is the patent-pending indoor waterfall, which first debuted in the team’s 2007 entry in the competition, LEAFHouse. "The waterfall provides humidity control in an aesthetically pleasing manner, and quickly brought an explosion of interest," revealed Amy Gardner, an associate professor of Architecture at the university, who served as principal investigator on both LEAFHouse and WaterShed.

The team used a skylight and bay window for natural lighting and an electric daylight dimming system. "In addition to windows on the south side, our house [is also] lit from the north," explained University of Maryland Project Manager Alex Yasbel. "We can do that because window technology has improved so much. The comfort and aesthetic appeal that comes with having windows on both sides outweigh any energy loss. Light from the north and south means you will be evenly lit — no harsh shadows, no feeling like you’re living in a cave."

The Maryland students also excelled in hot water system design; theirs supplied both domestic hot water and hot water for the radiant floor heating system. Buena Vista, Colorado-based Thermomax manufactured the solar thermal system. It is based on evacuated glass tubes with a collector medium in the tubes to transfer heat. This system is more efficient than a flat-plate collector, especially during winter, because it collects more heat from a given area.

"WaterShed achieves an elegant mix of inspiration, function, and simplicity," reported Architecture Juror Michelle Kaufman. "It takes our current greatest challenges in the built environment— energy and water —and transforms them into opportunities for spatial beauty and poetry while maintaining livability in every square inch."

In a concurrent, online People’s Choice Award, North Carolina-based Appalachian State University’s Solar Homestead took first place. This award category gives the public the opportunity to vote for their favorite house. This year, 92,538 votes were cast. The award was announced at a Victory Reception in the Solar Village—the last official event of Solar Decathlon 2011.

The Solar Homestead is a self-sustaining net zero-energy house inspired by the pioneer spirit of the early settlers to the Blue Ridge Mountains. The home actually comprises multiple buildings, which form a self-sufficient ensemble. Six outbuilding modules connect to form the Great Porch, an outdoor living space protected by an 8.2-kW trellis of bifacial solar cells. Inside, the house features two bedrooms, a day-lit bathroom, energy-efficient appliances, and a versatile living and dining area. The Solar Homestead also includes an independent 120-foot Flex Space, which features a half-bath, outdoor shower, and outdoor kitchen; and can serve as a home office, guest suite, or cabin retreat.

In addition to the solar panels on the Great Porch trellis, the home features an on-demand solar thermal domestic hot water system that uses phase-change materials to provide constant water temperature in compact storage.

"The Department of Energy would like to thank these incredible students, who represent the clean energy workforce of tomorrow and who helped bring this Solar Decathlon competition to life,” said Richard King, director of Solar Decathlon for the U.S. Department of Energy."

In previous U.S. Solar Decathlons, Team Germany of Technische Universität Darmstadt took first place in 2009., as well as in 2007 (when the University of Maryland came in second); in 2005, University of Colorado-Denver and Boulder, was the top winner, as it was in 2002.