Facebook doubles the size of its first data center

Facebook has decided to double the size of its planned data center in Oregon before the first part of the project is even built, the latest sign of the company's rapid growth.

Facebook said in January that it was building its first wholly owned data center in Prineville, Oregon, a 147,000-square-foot facility that's due for completion early next year. It's now decided to add another 160,000 square feet of data center space on the same site.

"To meet the needs of our growing business, we have decided to go ahead with the second phase of the project, which was an option we put in place when we broke ground earlier this year. The second phase should be finished by early 2012," Tom Furlong, Facebook director of site operations, said on the company's website Friday.

Facebook was approaching 400 million users when it announced the data center in January. Last month it crossed the 500 million mark.

Twitter said recently that it too will soon have its own data center. Like Facebook, its servers today are housed in data centers managed by other companies. Having its own facility will give Twitter more control over its infrastructure and, it hopes, reduce its outages.

Facebook said it employs 150 to 200 workers each day at the construction site. The data center itself will create 35 long-term jobs.

Greenpeace won't be thrilled at the expansion plans. The environmental group has criticized Facebook for choosing a site where the local power company gets most of its electricity from coal-fired plants. Greenpeace says Facebook should have chosen a site near a source of renewable energy.

Facebook has countered that it picked Oregon because of its dry and temperate climate. That allows it to use a technique called evaporative cooling to keep its servers cool, instead of a heavy mechanical chiller. Facebook says the data center will be one of the most energy-efficient in the world.