Justin Kramer, project director for the Florida State University zero emission house, enters the house in Tallahassee, Fla. The house is completely solar powered. AP

Project director for Florida University's Solar House

Justin Kramer, project director for the Florida State University zero emission house, enters the house in Tallahassee, Fla. The house is completely solar powered. AP

Justin Kramer, project director for the Florida State University zero emission house in his office at the house, in Tallahassee, Fla. AP

Justin Kramer, project director of the Florida State University zero emission house, demonstrates how the flame from a hydrogen stove, heats straight up and not out to the side, in Tallahassee, Fla. The house is completely solar powered and uses hydrogen for the stove. AP

This is the artist rendering of the Florida State University zero emission house, Thursday, Sept 24, 2009, in Tallahassee, Fla The house is completely solar powered. AP

Cornell University's submission on display

Cornell University's submission to the US Department of Energy Solar Decathlon sits on display at the National Mall in Washington, DC, October 7, 2009. Each of the house's silosókitchen, bedroom, and living rooms 16 ft (4.9 m) in diameter, with about 130 ft2 (12.1 m) of floor space. The modules are joined on the southern side, leaving the northern side open. The exterior is covered with COR-TEN, a corrugated, steel cladding that loses its original sheen as the outer layer oxidizes to a weather-proof ruddy coating. AFP

Team Germany's submission on display

Team Germany's submission to the US Department of Energy Solar Decathlon sits on display at the National Mall in Washington, DC, October 7, 2009. Team Germany started with a 'focus on the facade,' 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 percent of the energy needed by the house. AFP

University of Louisiana's submission on display

University of Louisiana at Lafayette's submission to the US Department of Energy Solar Decathlon sits on display at the National Mall in Washington, DC, October 7, 2009. The house is a hybrid structure in every sense. With a focus on the culture and lifestyle of south Louisiana, BeauSoleil combines traditional, local design concepts with the latest innovations in energy efficiency and solar technology which uses the porch's skylight to partially shade the south side creating a unique solar thermal system that heats the house's water. AFP