Google improved energy efficiency of its data center infrastructure in 2011, going to a trailing 12-month average Power Usage Effectiveness (PUE) of 1.14 from 1.16 reported for 2010, according to a blog post by Joe Kava, the company’s senior director of data center construction and operations.

Google’s data center team lives by the credo that says one cannot improve what one cannot measure, Kava writes.

Google has one of the largest but also one of the greenest data center infrastructures among the world’s companies. While it’s easy to brush this fact off by saying Google can do it because it has the resources and the scale that’s necessary, it does not mean smaller companies are powerless to make a meaningful dent in the industry’s impact on the environment.

Google’s six data centers on US soil have been successfully audited for systematic efforts to diminish their impact on the environment and for being safe and healthy work environments.

Joe Kava, senior director of data center construction and operations at Google, wrote in a blog post that Google was the first “major internet services company” go get third-party certifications like these for all of its data centers.

One of Google’s most innovative data centers is performing much better than expected, and according to Google’s Joe Kava, the seawater cooling that has gained it the most attention is actually exceeding design expectations.

Google’s Hamina data center, made from an old paper mill in Finland that had granite tunnels to bringing water for paper making, has been running since September, and Google will start reporting its PUE’s along with its other facilities in the US and Europe in the next quarter.

Google expects to reach a fleet-wide data center PUE of 1.12, but anything lower than this will end up costing the company money, despite its policy of offsetting all of the company’s carbon.

Google senior director of data center construction Joe Kava called it the asymptotic range, the “point where it (PUE) is flattening out” meaning the gains are becoming smaller and smaller.

“I think there are still a few ticks of efficiency that can be gained. We are currently at 1.14 and we will probably get to fleet-wide average of 1.12,” Kava said.

DCD FOCUS: You are discussing Google’s Hamina data center at DatacenterDynamics London. What makes this project stand out from the both terms of Google data centers and other large corporate operations?