For companies large and small, going green is now a surefire way to cut through advertising clutter, Slate reports.

Westport Wash & Wax, for example, has installed 18 solar panels at a cost of $21,000 (the state is paying 60 percent). Even with that subsidy, it’ll take seven years for the carwash to recoup the investment. On sunny days, the panels will only run the shop’s refrigerators and lights.

But the spending has made a lot of sense for the carwash – which has no advertising budget. Within two weeks of installing the panels in August, the carwash was featured in the two local newspapers, a Web site covering Westport, and the cable-news channel that covers Fairfield County. The New York Times has called, too.

Green companies can earn valuable free air time that doubles as an objective third-party endorsement, according to the article. Look at all the coverage received by Wal-Mart recently and you’ll understand the pull that green PR has these days.

In May, BuzzMetrics reported that Wal-Mart was the corporation most linked with blog posts that mention “sustainability.” Wal-Mart was mentioned in 1.77 percent of the 356,403 messages about sustainability measured between 3/15/06 and 3/15/07.