Germany Wins Solar Decathlon for Second Time

Team Germany, made up of students from Technische Universität Darmstadt, has taken first place in the 2009 Solar Decathlon competition, repeating its performance from the last competition, held in 2007 (see EBN Dec. 2007). The biennial student competition, run by the U.S. Department of Energy (DOE), is designed to demonstrate net-zero-energy homes and spur innovation.

Team Germany’s home was covered in solar cells: an 11-kW photovoltaic (PV) system on the roof made up of 40 single-crystal silicon panels and about 250 thin-film copper indium gallium diselenide (CIGS) panels spread over all four walls. Taken together, the PV systems produce approximately twice the electricity needed by the house, carrying the team into first place in the net-metering contest, new to this year’s competition. Team Germany also used some cutting-edge materials, including vacuum-insulated structural panels and phase-change materials in the walls and ceiling. Automated louvers on the windows were designed to maximize daylight exposure while controlling solar heat gain.

The University of Illinois at Urbana-Champaign took second place in the competition with its superinsulated house designed to echo traditional designs from the Midwest. Using salvaged barn wood, the team constructed a house with large amounts of insulation and high-performance windows, boasting that it could be heated with the equivalent of a hair-dryer. A 9.1-kW photovoltaic system on the gabled roof provides more electricity than needed by the house. The Illinois team hopes that a version of the house will soon be available to the public through a partnership with a modular home manufacturer.

Team California, which included students from Santa Clara University and California College of the Arts, designed its third-place-winning house to take advantage of the California climate, with south-facing windows and a protected courtyard to promote outdoor living. Passive solar design in the mild climate eliminates most heating needs, and a solar-thermal absorption chiller supplies radiant cooling panels. Waste heat from the chiller preheats water for the solar hot water system, and an 8.1-kW photovoltaic system provides all of the house’s electricity.

A total of 20 teams were entered in the 2009 Solar Decathlon, and their projects were on exhibit on the National Mall for two weeks during October. According to DOE, this year's event broke previous records, attracting more than 300,000 house visits and more than 2 million website page views.

For more information:

Solar Decathlon

www.solardecathlon.org