The federal government and major industry groups are on the cusp of developing widely accepted standards for measuring a data center's energy efficiency.
Along with the Environmental Protection Agency (EPA), the U.S. Department of Energy (DOE) is working with six data center industry groups: 7x24 Exchange, the American Society of Heating, Refrigerating and Air-conditioning Engineers (ASHRAE), the Green Grid, the Silicon Valley Leadership Group, the U.S. Green Building Council, and the Uptime Institute. The goals? To standardize data center efficiency metrics, which could help prevent "greenwashing," and to give data center pros tools to reduce energy consumption in their facilities.
Earlier this month, the coalition agreed to guiding principles regarding power usage effectiveness (PUE), which compares total data center power with IT power used. And by June, the EPA's Energy Star program will launch a benchmarking program that will enable companies to rate their own data centers on a scale of 1 to 100. If they're green enough, data centers can even earn Energy Star status.
Data center energy efficiency still poses confusion
Does all this matter to end users? In a 2009 SearchDataCenter.com survey, almost 90% of respondents said that reducing power consumption was very important or somewhat important. These standards can help data centers become more energy efficient. Still, while energy efficiency may be on data center pros' priority lists, it's not necessarily at the top.
"Our new data center will have significantly less power," said Rick Donohue, the IT director at Americas' SAP Users Group (ASUG) "If I had to justify green, I could do it. But my bigger priority was getting into a class-A data center."
ASUG is moving from an older data center into a newer one, and just the move into a newer building alone can increase a facility's energy efficiency. The same goes for traditional server refreshes. Installing new, less power-hungry servers, is where Energy Star-qualified servers can help.
Paul Scheihing, the technology manager for DOE's Industrial Technologies Program, said there has been confusion and inconsistency around how PUE should be measured and reported. As a result, there is some lack of confidence on the PUE figures reported in the media and elsewhere, and therefore uncertainty in how accurate the metrics are, he said.
"If there's confusion, then it's a barrier in terms of people measuring data centers in a comprehensive way," he said.
New principles for energy efficiency
For the DOE and EPA, new standards for data center energy-efficiency methods re important, because these organizations are on a mission to reduce overall data center energy consumption. But Scheihing said that they are also important for data center managers, because energy use affects the bottom line. Savings on regular energy costs aside, more efficient data centers spend less on capital equipment such as air conditioners.
The coalition devised three main guiding principles:
- PUE is the preferred energy efficiency metric for data centers
- To calculate PUE, IT energy consumption should be measured at least at the output of the uninterruptible power supply (UPS). (The industry should work toward measuring the IT load directly at the IT equipment.)
- Total energy measurement should be at the point of utility handoff to the data center owner. For a data center in a mixed-use building, total energy should be all the energy required to operate the data center, including IT energy, cooling, lighting and support infrastructure.
On the EPA side, the Energy Star program is updating its Portfolio Manager software to include data center facilities. That should be ready June 7, according to Alexandra Sullivan, an engineer in the EPA's Energy Star program for commercial buildings. The software will allow companies to rate their data center's energy efficiency from 1 to 100, a scale similar to that for other commercial buildings. On that scale, 50 is considered average and any building scoring 75 or higher will receive the Energy Star label.
But considering data centers' intense energy footprint, the model used to rate data centers is different.
Between March 2008 and June 2009, Energy Star collected energy information from more than 100 data centers. T then developed a regression model to determine the average data center's energy efficiency. PUE was used as the main efficiency metric, and in most cases the IT load was measured at the UPS. The group's PUE ranged from 1.25 to 3.75, and averaged 1.91.
"I think the benefit for [data center pros] is that they're saving money," Sullivan said about the Energy Star program for data centers. "And they could get an Energy Star plaque to put on their building so that their customers would know. I think there is also increased prevalence of Energy Star in the commercial marketplace."
Mark Fontecchio can be reached at firstname.lastname@example.org.