I may have to de-friend Facebook's green data center.

The Prineville, Ore., facility the company announced at the end of last month, received kudos and accolades for its innovative and dedicatedly green features, including a low-energy evaporative cooling system, an airside economizer for using outside air to cool the facility, a system to re-use of server heat, and a target of hitting a PUE of 1.15.

But at least some of the power going in to the data center will be from a notoriously non-green energy source: Coal. Not even "clean coal," just coal.

The company is under fire in the media and on Facebook, with online activist website Change.org launching a petition to "Stop Facebook from Switching to Dirty Coal."

The complaints arise from the fact that Facebook has contracted with PacifiCorp subsidiary Pacific Power to supply the energy for the facility. As reported on SearchDataCenter.com, "While Pacific Power gets some hydropower from [the hydroelectric generator Bonneville Power Administration], its primary power-generation fuel is coal, according to Jason Carr, the manager of the Prineville office of economic development for Central Oregon."

Some of the largest tech companies have sited their data centers in the same region where Facebook plans to build, and one of the primary drivers for those choices is that hydroelectric power comes in large quantities and rock-bottom prices from dams on the Columbia River. (When it comes to energy, green is, as with so much in IT, an auxiliary benefit and a side note to saving serious money.) And this is the first time I've heard a data center criticized for the energy used to power their facility, so while it's perhaps not undeserved, it could also be a case of a company getting dinged for sharing too much information.

In response to the mini-uproar, a Facebook representative commented on DataCenterKnowledge, saying in full:

I'm writing on behalf of Facebook to share their response to the issues you've posed. Most electrical commercial and residential power in the United States comes from a variety of sources. Our new data center will be receiving our power through PacifiCorp, which like most utilities has a diverse generation portfolio including hydro, geothermal, wind and coal. PacifiCorp is now the #1 utility owner operator of renewables, having grown their portfolio 2,400 percent over the past three years.

When it comes online in early 2011, the new Facebook data center will also be one of the most energy efficient in the world, featuring an innovative cooling system created for the unique climate characteristics in Prineville, Oregon.

The new, world class energy-efficiency technologies the Facebook data center will utilize include an evaporative cooling system; an airside economizer that will bring colder air in from the outside; re-use of server heat to warm office space in the colder months; and new patent pending highly efficient electrical design will reduce electricity usage by up to 12 percent. The entire facility will be built to LEED Gold standards.

The State of Oregon has a very aggressive Renewable Portfolio Standard, calling for 25 percent of power in the state to be produced by renewable resources by 2025. Facebook believes this policy will ensure continued growth of renewable generation resources. Facebook's commitment is, regardless of generation source, to use electricity as wisely and as efficiently as possible.

Maybe FB is getting more heat than it deserves for this revelation, or maybe it is simply on the early end of an increase in concern about what powers the servers that power the internet. I'd love to hear your thoughts in the comments, and I'll be sure to look at the energy mix for future green data centers that pop up on my radar.