You see them everyday and everywhere. Large retail outlets like Walmart, Kohl’s, and Whole Foods Market with vast floor space. They’re so big that by the time you’re finished shopping in one of them you’re exhausted and ready for a nap. But, have you ever thought about their roofs? Chances are you haven’t, but large-scale retailers are beginning to realize that they can put that square-footage to work for them. How? By installing solar energy systems to generate a substantial portion of their electricity needs.

For instance, Kohl’s last year began installing solar panels on 85 of its store and have systems already producing electricity in 43 of them. In mid-2007, Kohl’s began to convert most of its California locations to solar power. In fact, the closing of that deal with the Beltsville, Md.-based SunEdison, the largest solar energy service provider in North America, was the largest purchase and deployment by a single entity of solar power generation in U.S. history. “It takes our roof from being something not very glamorous to being very useful,” Ken Bonning, executive vice president of logistics, told the Milwaukee Journal-Sentinel. In terms of the amount of carbon dioxide emissions Kohl’s efforts will displace, that is the equivalent of taking 2,500 cars off the road, he said.

Retailers are turning to solar power more and more as executives of major retailers consider the advantages of installing solar power systems on their stores, not to mention bragging rights. “It’s very clear that green energy is now front and center in the minds of the business sector,” said Daniel Kammen, an energy expert at the University of California, Berkeley, speaking to the The New York Times. “Not only will you see panels on the roofs of your local stores, but I suspect very soon retailers will have stickers in their windows saying, ‘This is a green energy store.’”

Walmart is considering a renewable energy program that may soon see the deployment of solar electric systems on hundreds of it’s stores. But, Walmart is already well under way in their use of solar energy technology with systems installed at 17 of their stores and distribution centers around the country.

Whole Foods Market is a leader in the large-scale retailer solar power revolution. Their comprehensive solar energy plan seeks to team up with local energy companies to use solar power in their stores whenever possible. They have large solar arrays at three of their California locations including Los Angeles, Brentwood, and Woodland Hills. One of those locations, Brentwood, uses solar panels to produce 24 percent of its electricity needs. Creating enough electricity to power 20 residential homes, the 62,000 kilowatt hours of power result in the displacement of about 70 tons of CO² and 58 tons of coal emissions. And, Whole Foods Market has no plans ot stop there.

The advantage for clean air and green living fans is clear. As this retailers-with-large-roofs solar energy revolution continues, every small gesture that adds to the capacity of solar and alternative energy generation is a victory we can applaud as we attempt to transition to a new, cleaner world.