Not sure what the secret is, but Apple is quietly clearing 174 acres of land in North Carolina for a solar farm to power its new $1 billion data center, which will also be sited there.

No one knows how big The “Project Dolphin Solar Farm” will be – all that’s known is they’re setting fires to clear the land. Neighbors complain the fires go 24 hours a day. The company hasn’t yet applied for a building permit, which would disclose that information.

The data center, also called “Project Dolphin” has been online since this spring. At 500,000 square-feet, it’s five times the size of Apple’s Newark, California center. Apple will power iTunes, MobileMe and its new iCloud service there.

Apple has a handful of facilities that run completely on renewable energy: in Austin, Texas; Sacramento, California; and Cork, Ireland. It says it uses state-of-the-art digital controls, high-efficiency mechanical equipment, and monitoring technology.

It’s also got a patent to incorporate solar panels on small devices like the iPod.

Apple was taken to task for years for not reducing toxics in its products, not actively encourage recycling at end-of-use, and for its lack of transparency on reporting its greenhouse gas emissions and other environmental standards. It’s since improved on most measures.

See Apple’s environmental site:

Website: www.apple.com/environment/#facilities

Original Article on SustainableBusiness.com