Ten Eco-Friendly Companies

New rivals like GE and Siemens are getting into the wind turbine business. Engel welcomes them, saying these "big and powerful corporations are spreading the word about the potential for wind." He adds: "The industry is taking on a new dimension." And becoming a bit more like Denmark.

--Karen Lowry Miller

8 A Very Light Touch

PowerLight: Making solar systems pay off for homeowners, businesses and governments

Some men root for their local sports teams, others for individual athletes. Dan Shugar's allegiances belong to the two solar-powered Mars rovers, Spirit and Opportunity. The rambling robots, designed to last just 90 days, continue to thrive in their 20th month of exploration on the Red Planet. Shugar, president of the solar-installation firm PowerLight, roots for the rovers because they're symbols of the reliability and durability of harnessing energy from the sun. He checks NASA Web sites to follow their progress and cheers when they overcome adversity. "There were predictions that the rovers wouldn't make it through the first winter, but they are still going strong. I think that is just fabulous," he says.