Apple doesn’t toot its horn much about its efforts to reduce its corporate carbon footprint. (I don’t count the Apple and the Environment website that nobody I know has read.)

According to Fehrenbacher, the easiest way to sense the scale of Apple’s clean energy operations is to drive past its huge Maiden, N.C., data center on U.S. 321.

“In the world of clean energy,” she writes, “there are a lot of ways that companies can pay to green their operations — many buy renewable energy credits that offset consumption of fossil fuel based energy. But building solar farms and a fuel cell farm next to a data center could be the surest way to add clean power in a way that can be validated and seen by the public. It seems like Apple execs thought if they were going to commit to the whole idea of clean energy, it was going to be all the way.

“The effects of the clean energy projects on Apple’s brand also can’t be discounted. Apple has a powerful and potentially fragile consumer brand, and the data center in North Carolina was a major push for Apple to move more heavily into cloud services. A record for the largest privately-owned solar farm in the U.S., could add significant branding capital to a brand trying to stay on top.”

Perhaps. But doing its part to reduce global warming doesn’t seem at all out of character for Apple.

My three favorite facts from Fehrenbacher’s story:

• In North Carolina, Apple hires local sheep to trim the grass under its 200 acres of solar collectors.
• Its fuel cells generate so much thermal energy you can see heat waves rising above them.
• Duke Energy, which used to generate most of its electricity from coal, has turned quite green since Apple, Facebook (FB) and Google (GOOG) planted their servers in the Tar Heel State. 

LINK: Special report: Apple’s ground-breaking bet on its clean energy infrastructure, with exclusive photos.