Oct. 26, 2007 - Technische Universität Darmstadt is the overall winner of the 2007 Solar Decathlon. This competition challenges 20 college teams from around the world in 10 contests to design, build and operate the most livable, energy-efficient, completely solar-powered house. Solar Decathlon houses must power all the home energy needs of a typical household using only the power of the sun. Two previous Solar Decathlons have been held, with the first in 2002 and the most recent in 2005. The University of Colorado was the overall winner of both previous Decathlons. To minimize the amount of energy needed to provide an optimum of living comfort a compact house shape with a highly insulated building envelope was choosen for the award winning house of TU Darmstadt. During summer times overheating is avoided by an overhang and the moveable louver frames in the south. Wax based microcapsules embedded in gypsum plasterboards are serving as thermal mass, storing the heat additionally and releasing it during the colder night times. In the winter days the heating energy is gained from the sun coming through our huge south facing window faade. The highly insulated walls and windows keep this heat inside the house. If the solar irradiation is not sufficient the supply air can be additionally heated with a reversible heat pump which gets its energy from a photovoltaic system. The same heat pump is used to support a solar collector producing the domestic hot water.
