The ICON House built by a team of engineers from the University of Minnesota captured the prize for best lighting design in the 2009 Solar Decathlon, sponsored by the U.S. Department of Energy.

The Solar Decathlon drew competitors from around the world in a bid to build the most energy-efficient, solar-powered house on the National Mall in Washington, DC. The team from Germany took the prize in the overall competition.

ICON House won the lighting design competition for designing functional, energy-efficient and aesthetically pleasing lighting systems using both natural sunlight and electric lighting.

The University of Minnesota team used strategically placed windows for maximizing day light and energy-efficient solid state LED lights.

"The ICON House is designed with features that offer maximum efficiency of light around the house, interior and exterior, natural and artificial," the team reported on its blog.

The selective design integrating electric and natural light was so efficient that it allowed the team to use less than 500 watts for both interior and exterior lighting - less than the equivalent of five 100-watt incandescent bulbs.