Team Germany started with a "focus on the façade," creating a house that is essentially a two-story cube. The surface is covered with solar cells: an 11.1-kW photovoltaic (PV) system made of 40 single-crystal silicon panels on the roof and about 250 thin-film copper indium gallium diselenide (CIGS) panels on the sides that are expected to produce an incredible 200% of the energy needed by the house. The CIGS component is slightly less efficient than the silicon but will perform better in cloudy weather. The façade's highly insulating, custom vacuum insulation panels plus phase-change material in the drywall maintain comfortable temperatures. Automated louver-covered windows block unwanted solar heat.
The team is relatively small with only 24 students, mostly architects. But team member Sardika Meyer relates how many others took part. "Even my boyfriend, all the families and friends got involved," she says. "We had so much support; it was really incredible." Team Germany finished first in Solar Decathlon 2007, and the 2009 team has relied on members of the 2007 team for guidance.
The Team Germany philosophy was to "push the envelope with as many new technologies as possible." In particular, the house was designed to maximize PV production and use of the net-metering connection to the electric utility grid on the National Mall. The result is a two-story, cube-shaped building with PV panels on the roof and sides and a single multifunctional living area on the inside. Described by the team as an aesthetic solar design, the house has a bed and other furniture and appliances that fold away or serve multiple purposes.
The extensive PV panel deployment is the most notable feature of the Team Germany house, but other technologies include: