Google announces it has further increased the energy efficiency of its data centers, you can read about it at the Google Blog. The search engine giant claims its data centers use 50 percent less energy than typical data centers.
One of the measurements we track is PUE, or power usage effectiveness. PUE is a ratio of the total power used to run a data center to the amount used to power the servers. For instance, if a data center has a PUE of 2.0, that means that for every watt of energy that powers the servers, another watt powers the cooling, lighting and other systems. An ideal PUE would be 1.0.
In 2011, our trailing 12-month average PUE was approximately 1.14—an improvement from 1.16 in 2010. In other words, our data centers use only 14 percent additional power for all sources of overhead combined. To calculate this number we include everything that contributes to energy consumption in our data centers. That means that in addition to the electricity used to power the servers and cooling systems, we incorporate the oil and natural gas that heat our offices. We also account for system inefficiencies like transformer, cable and UPS losses and generator parasitic energy draw.