Apple has kicked off construction of the first of two large data centers it plans to erect in Prineville, Oregon, across the highway from a massive Facebook facility, The Oregonian reported. Crews have started clearing and flattening land for the building.

The company already has a small (10,000 sq ft) data center at the site, but the plans include about 500,000 sq ft of data center space spread over two large 300,000-plus-sq-ft buildings. The 160-acre property, which Apple bought from Crook County in February for US$5.6m, also allows for expansion beyond what has been planned.

Apple has publicly committed to powering its Prineville data center (once built), as well as its recently completed Maiden, North Carolina, data center, using only renewable energy. It has not said how exactly it was going to do it in Prineville, where its neighbor Facebook has been slammed by environmentalists for buying coal-based energy from the local provider Pacific Power.

“At Prineville we have access to enough local renewable energy sources to completely meet the needs of the facility,” Apple said on its website. “To achieve that goal, we’re working with two local utilities as well as a number of renewable-energy generation providers to purchase wind, hydro and geothermal power — all from local sources.”

To be fully clean in Maiden, the company said it was building two massive solar arrays (one at the site and the other away from it but in the area) and installing fuel cells by Bloom Energy that convert natural gas into electricity.

Apple expects these installations to take care of 60% of the facility’s 20MW peak demand. It said it would buy the rest directly from local and regional suppliers of renewable energy.

In addition to Maiden, Apple has a data center in Newark, California, which it also plans to power fully by clean energy by February 2013.

The company is also planning to build a data center in Reno, Nevada, on the site of a future technology park, whose developers offer access to many renewable-energy options. The company has not, however, disclosed its energy-procurement plans for the future Reno Technology Park facility.