It was the Green Grid that came up last year with the PUE ratio, which provides a way to measure overall data center efficiency and has been used by Microsoft and Google to show off the efficiency of their most state of the art data centers.

It can be hard for everyday companies to know what sort of PUE ratio they should aim for or how to measure it, so the consortium will also release a paper in the coming months that tells them just that, said John Tuccillo, another Green Grid board member and the vice president for global industry and government alliances with American Power Conversion.

The consortium will also propose methods for measuring the "useful work" performed by data centers. All these metrics are important, proponents say, because businesses can't set accurate targets for energy efficiency if they don't know how efficient their data centers are to start with. "You can't manage what you can't measure," is a refrain commonly heard at these conferences.

The U.S. Environmental Protection Agency has estimated that data centers accounted for 1.5 percent of the nation's electricity consumption in 2006, and it said that figure could double by 2011. Many companies are facing energy problems in their data centers, as powerful modern servers and the shift to doing business online stretches their power and cooling capacities.