Google announced today that it will be buying wind-generated power from a company called NextEra Energy Resources to sell back to the local grid operator in exchange for Renewable Energy Certificates (basically, credits to offset its carbon emissions).

The company made the purchase via its relatively new Google Energy unit — an entity that won the rights to buy and sell energy just like a utility from the Federal Energy Regulatory Commission in February.

This isn’t the first time Google has worked with NextEra. The search giant has already invested $38.8 million in two wind farms — pumping out 169.5 megawatts total — developed by NextEra in North Dakota. But starting on July 30, Google will be buying 114-megawatts of power from NextEra’s farm in Iowa at a flat, undisclosed rate.

Reuters initially reported that Google was buying the power to run several of its data centers, but this doesn’t appear to be the case. That’s not to say that renewable energy, derived either from wind or solar, won’t eventually be used to power up data centers, or even some of its campuses, just not right now.

When Google Energy was first formed in December, speculation swirled that the company planned to launch its own utility to compete with the likes of Pacific Gas & Electric and Southern California Edison. But the company fended off these guesses, saying only that it wanted the ability to buy and sell a greater amount of renewable energy on the wholesale market — a key pillar in its plan to achieve carbon neutrality.

The deal with NextEra is consistent with this mission, and there have been no signs of Google Energy expanding its purview beyond this type of transaction. In addition to expanding its green portfolio, the deal will also allow Google to purchase energy over 20 years at the same rate — insulating itself from inevitable price hikes.

Google has several other energy-related projects ongoing. Google PowerMeter, its consumer-facing system for tracking energy use and costs, just lost its leader, Ed Lu, but may be switching course when a replacement takes the helm. Google Ventures and philanthropic arm Google.org have also funneled millions into companies developing new solar, wind, geothermal and smart grid technologies.

Several of the company’s higher-profile green investments include grid communications firm Silver Spring Networks, solar thermal developers BrightSource Energy and eSolar, and innovative electric vehicle company V-Vehicle.