What we know: Apple is building something at its Maiden, North Carolina, data center. What we don’t: What it is. So Wired took to the skies to find out.

Wired Enterprise’s enterprising writer Robert McMillan reports:

These overhead photos — captured last month — show Apple’s $1 billion data center and two adjacent areas where Apple has started new construction. Rumors have suggested that Apple is building a second data center beside the first, but judging from these photos — and county building permits — it appears that this is not the case. In all likelihood, the two construction areas will house the new-age biogas fuel cell plant and the massive solar array Apple will use to help power the original facility. Apple’s solar array effort has already come under fire from a data center guru James Hamilton at rival Amazon, who said last month that it just may not make sense to use so much land for a solar array that may end up generating a fairly small fraction of the data center’s power. Apple bills its solar farm as a 20-megawatt array, but that represents the solar farm’s peak capacity on a sunny day. In reality, it will probably produce less power than the 4.8-megawatt biogas facility, according to Gary Cook, an IT analyst at Greenpeace.

Now biogas? McMillan reports: But Apple finds itself in this situation because it’s trying to reduce its reliance on the environmentally unfriendly energy sources — primarily coal and nuclear — that power the Duke Energy grid that Apple uses, says Greenpeace’s Cook. “They’re trying to do what they can onsite to reduce their emissions footprint,” he says. “It’s a very dirty energy grid — North Carolina is 60 percent coal, and this is one way to try to reduce that load.”

It’s certainly not easy being green. But is this pure marketing, or will solar and biogas make a difference when iCloud becomes a personal cloud storm?