SAN JOSE, CA — By this summer, your data centers may be able to earn an Energy Star certification, if the final stages of work underway at the U.S. Environmental Protection Agency conclude as planned.

At The Green Grid's data center conference in San Jose last week, Energy Star manager Alexandra Sullivan told attendees that the certification could be ready as early as June.

Once the certification is launched, companies will be able to take an online test to rank how efficient their facilities are. Companies that score in the top 25 percent will then be eligible for an audit by the EPA in order to earn the Energy Star label.

Measurements for Energy Star certification will be largely drawn from a data center's power usage effectiveness (PUE) ratio -- the amount of power entering a facility that goes to computing rather than lighting, cooling or other non-computing operations. The reliance on PUE could cause some wrinkles in the certification, according to IDG News Service:

The program is likely to stir some debate. Some attendees at the Green Grid event were surprised other criteria won't be included, such as whether a data center is located in a cool or warm climate, or the level of redundancy it provides.

"You have to take the environment into account because it's easier to have a low PUE score if you're in a cold climate," said Don Klein, vice president of marketing and business development with Modius, which makes tools for measuring data-center energy use.

Not so, according to Sullivan. The EPA analyzed data from 108 data centers and determined that only the UPS output needs to be taken into account.

"We were surprised to find there weren't many operational variables that had a statistically significant impact on PUE," she said. "The variability is much more dependent on energy management practices than it is on characteristics."

The EPA is working on a number of certifications for enterprise computing; in addition to its forthcoming data center certification, another certification for data center storage systems is in the works, and last year the EPA released its Energy Star for Servers certification.