Solar Decathlon Houses Feature PV, BIPV and Energy-Efficient Windows
September 22, 2011

By Sahely Mukerji, smukerji@glass.com

Amy Howard, project manager of University of Tennessee team, describes the features of Living Light.

The Appalachian State University team cheers in front of its Solar Homestead.

The PV system of University of Calgary's "Turtle" house operates 93 percent of its optimal efficiency.

Florida International University's perFORM[D]ance house uses floor-to-ceiling glass.

Victoria University of Wellington First Light House is 20 percent glass.

The U.S. Department of Energy's 5th Solar Decathlon opened today at the West Potomac Park, Washington, D.C. This year's 8-acre solar village includes 19 houses featuring innovative use of energy-efficient glass and sustainable design. Solar decathletes from five countries and four continents designed and constructed the novel structures.

All the houses feature photovoltaics (PV), says Richard King, director of Solar Decathlon. Some houses feature solar thermal power, while all are electric houses, he says.

The glass use in the following entries stood out:

• The University of Tennessee's 740-square-foot Living Light zero energy house features 40 feet of glass along the north and south faces, with 85 percent of its exterior envelope being glass, says Amy Howard, project manager. "The north and south walls are double-glass façades with the outer pane being single pane, R-1 with a low-E coating, and the inner wall is two layers of glass, two layers of Mylar with Argon fill," she says. "That's where we have the insulating value." The suspended film allows the entire wall system to be R-10, she says. "The sun heats up the air in the south façade during winter to supply pre-heated air to the house, and exhaust warm air through the north to prevent heat loss," she says.
  
  The university partnered with AGC Flat Glass North America of Alpharetta, Ga., which supplied all the glass in the house, Howard says. Kawneer Co. of Norcross, Ga., supplied the aluminum framing system.
  
  The solar panels on the house come from Solyndra of Fremont, Calif. "The flat orientation allows to extend the array as a shading device," Howard says. Each solar panel produces 182 watts per hours, and the whole array of 60 panels produces 10.9 kilowatts.
  
  
• University of Calgary's TRTL (Technological Residence, Traditional Living) zero-energy house features a PV system that operates 93 percent of its optimal efficiency, says Mikhael Horvath, mechanical lead. The total array of 32 solar panels is from Conergy of Germany produce 8.7 kW. The house, called "Turtle" from TRTL, also features triple-glazed windows from Innotech Windows and Doors of Abbotsford, B.C. The windows have an R5-plus rating, two low-E coatings, warm-edge spacers, Argon fill and hybrid steel framing, said Al Jaugelis, technical director of Innotech. "The frames are made of UPVC [unplasticized PVC], and everything in the frame is reinforced with steel that is bonded to the UPVC," he says. "They are very air-tight and have three weather seals."
  
  
• The Appalachian State University's zero energy Solar Homestead features a solar canopy that creates an outdoor living space, says Chelsea Royall, a team member. "The bifacial solar panels from Sanyo are integrated in the architecture, and produce8.2 kw and 195 watts per panel," she says. The concentrating solar skylight supplies all the hot water used in the home. All the windows in the house are triple-glazed, R5, and supplied by Kolbe of Wausau, Wis., except for the Trombe wall window. The Trombe window stores heat during the day and releases during the night, she says.
  
  
• Florida International University's perFORM[D]ance house uses floor-to-ceiling glass for exterior walls and foldable doors from NanaWall of Mill Valley, Calif., on three sides, says Deana Sritalapat, a team member. "The south walls are relatively solid because we didn't want it overheated," she says. "The glass is impact-resistant and provides the maximum amount of natural lighting while oriented north to provide a minimum level of heat gain. The interior of the glass is protected by operable shades and the exterior of the glass is protected by an operable louver system." SunPower in San Jose, Calif., supplied the solar panels on the house.
  
  
• New Zealand-based Victoria University of Wellington's First Light house is 20 percent glass. "All the glass is triple-glazed, Argon-filled and tempered," said Sophie Prebble, a team member. Metro GlassTech of New Zealand supplied the glass.
  
  
• Tidewater Virginia team, comprising Old Dominion University and Hampton University, built the Unit 6 Unplugged modular house that features an outdoor porch with sliding glass walls. The porch can be enclosed by closing the glass walls and works as a thermal collector. The double-glazed windows in the south face and the triple-glazed windows in the north face are supplied by Gayko of Germany, and the solar panels are from Sanyo and Bosch.

The Solar Decathlon consists of 10 contests, and each contest is worth a maximum of 100 points, for a competition total of 1,000 points. Click here to see a list of the participating teams and their work. Click here for more photos.

Need more info and analysis about the issues?
CLICK HERE to subscribe to USGlass magazine.