America’s big-box retail and grocery stores could fulfill half of their own electricity needs and generate enough clean electricity to power more than 7.9 million U.S. homes if they covered their ...

Solar panels cover the roof of a Sam's Club store on April 22, 2009, in Glendora, California. Solar energy offers a cheap, renewable source of electricity that could reduce and, eventually, eliminate ...

Last year, a reader wrote in to Grist’s advice column with a question: Why doesn’t every roof have solar panels? A report released this week by the nonprofit Environment America and the research firm ...