The Solar Decathlon 2007 in Washington, D.C., has turned into an international incident, with Germany's Technische Universität Darmstadt taking the top spot out of 20 universities in the week long competition.

The University of Colorado, the former champ, which holds trophies from the 2002 and 2005 contests, came in at No. 7.

Hosted by the U.S. Department of Energy, each team tries to build the most attractive and efficient solar-powered home, with all the comforts and appliances, packed into 800 square feet (see Solar gets competitive at the decathlon).

The teams constructed their model homes on the National Mall in the U.S. capital.

With a total of 1024.85 points for the 10 stages of the contest, the German students gained their biggest advantage in the all important architecture section, which counts for the most points.

"Perfecting structural stability with the creative use of space is crucial to quality architecture for solar-powered homes," said Alexander Karsner, assistant secretary for Energy Efficiency and Renewable Energy at the DOE.

The outside of team Darmstadt's home was covered in movable, folding, oak shutters, with photovoltaics incorporated into each slat.

Take a look at the house >>

They have until 2009 to get ready to defend their title at the next Solar Decathlon in the U.S., but they won't have to travel as far in 2010 for the planned Solar Decathlon Europe.

"With three successful Solar Decathlons to show, the Department of Energy looks forward to lending our expertise to encourage the same innovation and entrepreneurial spirit across the Atlantic and around the world," said Karsner.

Karsner signed a memorandum of understanding this week with Spain's undersecretary of housing to collaborate in the development of a competition in Madrid.

The Spanish team, Universidad Politécnica de Madrid, came in fifth place today, with 946.298 points.