Google announced that it recently signed a power purchase agreement for wind energy in Oklahoma. This is Google’s second PPA within the year. Last July, Google signed a PPA with NextEra Energy Resources to buy clean wind energy to power its data centers in Iowa.

The wind energy purchased in Oklahoma will be used to power the Mayes County Data Center, which is scheduled to be fully operational later this year. According to the PPA, Google will purchase wind energy from NextEra Energy Resources for the next 20 years. The 100.8-megawatt wind farm will be operational in late 2011.

Power purchase agreements (PPAs) are conditional agreements between a power purchaser and a renewable energy development company that will begin once the power plant starts its operation. With its deal with NetEra Energy Resources, Google will buy the wind power from the facility once the wind farm is completed and ready to deliver the power.

Google and other IT companies were also recently criticized by Greenpeace for using ‘dirty energy’ in their operations. Greenpeace claimed that the companies concealed details of their overall energy footprint and practices. Other companies mentioned in the report include: Akamai, Amazon Web Services, Apple, Facebook, HP, IBM, Microsoft, Twitter, and Yahoo.

Greenpeace noted that data centers consume 1.5 to two percent of the total global electricity, and this sector is growing at a rate of 12 percent each year. Greenpeace is concerned that most of the companies in the IT sector don’t release data about their energy use and carbon footprint, and stated that Facebook gets 53.2 percent of its power from coal power plants.

Google rebutted this claim by Greenpeace by announcing its PPA with NextEra Energy Resources. Google stated that it’s the company’s commitment to be carbon neutral and the company’s purchase is just part of its effort to minimize its impact on the environment.

Aside from its investment in clean energy, Google is also building high energy efficient facilities to reduce its carbon footprint. Google buys carbon offsets to help decrease its carbon emission further.

It is important that Google and other companies in the IT sector make it their goal to maintain ecological friendly operations and design their facilities to be more energy efficient. A recent survey from CompTIA showed that 37 percent of IT companies make it their priority to be green. This number is up from the measly nine percent in 2009.