In this photograph, people are reflected on Team Germany's window louvers with integrated thin-film copper indium gallium selenide (CIGS) cells during the U.S. Department of Energy Solar Decathlon 2009. 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.