TWENTY SOLAR HOUSES designed by college students around the globe are on display at the National Mall in Washington, D.C., as part of the U.S. Department of Energy’s fourth Solar Decathlon. These compact dwellings–none more than 800 square feet–rely on photovoltaic cells, passive solar energy, reclaimed materials and innovative new products to harness the sun’s energy and preserve our natural resources. (Some of the space-saving ideas are clever, too, like Team Ontario’s bed that descends from the ceiling.) As astonishing as the technology is the beauty of these designs, many of which could have commercial potential as second homes or accessory dwelling units. (A few I wouldn’t mind living in full-time.) The homes are open to the public through Sunday, October 18, or you can check out a video tour of each at solardecathlon.org.

Photo courtesy Solar Decathlon