Team Germany's winning "Cube House" featured silicon and thin-film solar panels on all visible sides of the house
The design’s solar panel operates a toy on the front porch of the home. Credit: Stefano Paltera/U.S. Department of Energy Solar Decathlon
Rain didn’t ruin the 2009 Solar Decathlon in Washington, D.C. University teams successfully operated 20 net-zero, grid-connected solar power homes for a week on the National Mall. Some used more power-generating solar panels; others relied on energy efficiency strategies. The winner was clean energy.
Rain usually spoils a solar power contest. But three days of showers — and thin-film photovoltaic technology — actually helped Team Germany win the 2009 U.S. Department of Energy’s Solar Decathlon.
Team Germany’s Cube House was one of the most technologically advanced among the 20 clean energy prototype designs on the National Mall. Every exposed face of the building was covered with power-generating panels.
On the roof : a 11.1-kW photovoltaic (PV) system of 40 monocrystalline silicon panels. On the sides: 250 thin-film panels that look like glossy clapboards. The thin films used copper-indium-gallium-diselenide layers, or CIGS.
The combination system was expected to produce 200 percent of the energy needed by the house. The thin film panels, while less efficient than conventional silicon, were projected to perform better in cloudy weather than silicon.
Team Germany got its proof on the competition’s fifth day when skies turned slate gray and a cold rain splattered the solar village. By late afternoon, as federal commuters started streaming home and electricity demand throughout the city began climbing, the Team Germany house was producing 12.68 kW and consuming 12.33 kW, for a net export of .35 kW.
Team Illinois’ house finished a close second, emphasizing energy efficiency over power production.
“Team Germany built a gingerbread house packed with solar panels,” said Richard King, DOE Solar Decathlon director. “In the rain, the thin-film panels were making electricity. It made the difference.”
NREL Manages the Decathlon
NREL has managed the biannual Solar Decathlon for DOE since the contest’s inception eight years ago. Selection of the 20 university teams from North America and Europe begins two years before the actual competition.
The Laboratory sent 30 people to run the week-long contest on the National Mall, including installation of the homes with trucks and cranes, connecting them to Washington’s municipal power grid, running the judged contests and monitoring the home’s continual performance.