A team from Technische Universität Darmstadt, Germany, won top honors for most attractive and efficient solar-powered home at the 2009 Solar Decathlon.
19 October 2009, SPIE Newsroom. DOI: 10.1117/2.1200910.0009
Team Germany, from Technische Universität Darmstadt, won top honors for the most attractive and efficient solar-powered home at the 2009 Solar Decathlon, which ended on October 18. More than 200,000 visits were recorded at the 20 solar-powered homes displayed on the national mall in Washington, DC, over a 10-day period.
The Solar Decathlon is a biannual competition sponsored by the United States Department of Energy (DOE).
Twenty university teams design and build solar-powered homes to meet strict design and efficiency criteria. The competition is intended to raise public awareness and further the integration of energy-efficient technology into residential building practices.
The University of Illinois at Urbana-Champaign took second place followed by Team California in third place. The winners were announced by DOE Deputy Secretary Daniel Poneman.
Team Germany's winning "Cube House" design produced a surplus of power even during several days of rain. This is the team's second straight Solar Decathlon victory, after winning the previous competition in 2007.
The surface of the Cube House is covered with solar cells, an 11.1-kW photovoltaic system made of 40 single-crystal silicon solar panels on the roof and about 250 thin-film copper indium gallium diselenide solar panels on the sides.
The side panels, popular among many of the designs in this year's competition, are slightly less efficient than silicon, but perform better in cloudy weather or in winter when the sun is lower in the sky. Clouds may have helped determine the winner of the Solar Decathlon, as the week wrapped up with four straight days of rain.
New to this year's competition, the Net Metering contest was worth 150 points in the final results and was the most heavily weighted contest. It challenged teams to generate surplus energy, above and beyond the power needed to run a house, which they fed into a power grid. Team Germany scored a perfect 150 points in this part of the competition.
Team Germany earned a total of 908.29 points out of a possible 1,000 to win the competition, followed by the University of Illinois at Urbana-Champaign with 897.30 points, and Team California with 863.08 points.
Solar Decathlon director Richard King of the DOE was pleased to see the tremendous public interest in the solar homes, even on the soggy days at the end of the week when leaks in the homes and muddy pathways between the houses posed challenges for contestants and visitors alike. King said that in this fourth iteration of the event, "the bar has been raised" and teams responded with innovative approaches to new challenges, such as the net metering requirement.
The 20 teams from the United States, Spain, Germany, and Canada competed in 10 contests, ranging from subjective elements such as architecture, market viability, communications, lighting design, and engineering, to technical measurements of how well the homes provided energy for space heating and cooling, hot water, home entertainment, appliances, and net metering.
The People's Choice Award, determined by ballots collected from the public, went to the University of Louisiana at Lafayette.
Appliances In the Appliances Contest, the University of Illinois at Urbana-Champaign earned the most points based on keeping a refrigerators and freezer cold, washing and drying 10 loads of laundry during the contest week, and washing dishes in a dishwasher five times during the competition - all on electricity generated only from sunlight. The team scored 93.53 out of 100 possible points.
Architecture Team California took first place in the Architecture contest and earned 98 points out of a possible 100. A jury of architects judged homes on the aesthetic and functional elements of the home's design; ease of circulation among the public and private areas; integration of various spaces into a holistic design; generosity and sufficiency of space in the house; and the house's design surprises meant to inspire visitors.
Comfort Zone Team Germany topped the contestants in the Comfort Zone contest, with 92 out of 100 points for maintaining indoor temperatures between 72 and 76 degrees Fahrenheit and relative humidity between 40 percent and 55 percent.
Communications Team California's communications efforts, including communications plans, student-led tours, and team Web site, were judged best by the jury of Web site and public relations experts with a score of 69.75 points out of a possible 75 points.
Engineering The University of Minnesota won the Engineering contest, which was evaluated by a group of prominent engineers, who determined which solar home best exemplified excellence in energy systems design, energy-efficiency savings, creative innovations in design, and reliability of energy systems. The University of Minnesota scored 96 out of a possible 100 points.
Home Entertainment The Home Entertainment contest required students to use electricity generated by their solar houses to run interior and exterior lights, a TV, a computer, and a kitchen appliance to boil water. Teams were also required to hold two dinner parties and a movie night for neighbors. The University of Illinois at Urbana-Champaign earned 92.62 out of a possible 100 points.
Hot Water The University of Illinois at Urbana-Champaign earned the maximum 100 points in the Hot Water contest's "shower tests," which aimed to deliver 15 gallons of sun-heated hot water in ten minutes or less.
Lighting Design The University of Minnesota was the winner of the Lighting contest where teams earned points based on an evaluation by a jury of lighting-design experts. Jurors toured each house to evaluate the aesthetics, innovations, energy efficiency, user-friendliness, flexibility, and performance of lighting designs. Minnesota earned 72 points out of a possible 75 points.
Market Viability The University of Louisiana at Lafayette won the Market Viability contest, which evaluated whether the cost-effective construction and solar technology in a team's design would create a viable product on the open market, based on livability, feasibility of construction, and marketability. The University of Louisiana at Lafayette earned 97 points out of a possible 100 as judged by the professional jury.
Net Metering Team Germany took the top spot in the crucial, 150-point Net Metering contest. Teams were awarded 100 points if the energy supplied to their home's two-way electrical meter registered zero or less after all of the energy demands of the contest week.
Each house in the 2009 Solar Decathlon was connected to a power grid and equipped with a meter that measured both its consumption and production of energy. When a team's meter showed a negative number, the home had generated surplus energy - worth up to 50 additional points.
Team Germany scored a perfect 150 points in this contest.