The Green Grid Association together with The Data Center Metrics Coordination Taskforce, has delivered its latest recommendations for energy efficiency measurement and reporting.

The new report, titled “Recommendations for Measuring and Reporting Overall Data Center Efficiency: Version 2 – Measuring PUE at Data Centers” completes the guidelines for applying the Power Usage Effectiveness (PUE) metric, created and promoted by The Green Grid. The new information includes specific recommendations for how to measure and calculate PUE in mixed-use data center facilities and introduces a condenser water source energy weighting factor. PUE determines the amount of energy used by a data center facility and the IT gear inside of it. A detailed explanation of PUE can be found on The Green Grid’s Web site.

Alignment on these methodologies across the industry will lead to consistent and repeatable measurement strategies that allow data center operators to monitor and improve the energy efficiency when operating their existing data centers, or when designing new facilities. The task force’s latest report represents the combined decision-making from the 7x24 Exchange, ASHRAE, The Green Grid, Silicon Valley Leadership Group, U.S. Department of Energy’s Save Energy Now and Federal Energy Management Programs, U.S. Environmental Protection Agency’s ENERGY STAR Program, U.S. Green Building Council, and Uptime Institute. The following principles were agreed to:

• PUE, using source energy consumption, is the preferred energy efficiency metric for data centers.
• When calculating PUE, IT energy consumption should, at a minimum, be measured at the output of the uninterruptible power supply (UPS). However, the industry will continue to improve measurement capabilities so that measurement of IT energy consumption directly at the IT load (servers, storage, network, etc.) becomes the common practice.
• For a dedicated data center, the total energy in the PUE equation will include all energy sources at the point of utility handoff to the data center owner or operator. For mixed-use data centers, the total energy will be all energy required to operate the data center, similar to a dedicated data center, and should include cooling, lighting, and support infrastructure for the data center operations.

“The task force has accomplished a tremendous amount of work to help the data center industry have a common understanding of energy efficiency metrics to improve data center efficiencies and reduce energy use,” said Dan Azevedo, Symantec representative and board member of The Green Grid. “We are looking forward to working with our colleagues on the next steps for the industry, including identifying a roadmap for future efficiency programs such as IT productivity and carbon accounting.”

The task force intends to continue collaborating in the years ahead to ensure that data center resource efficiency and productivity is delivered as consistently as possible across regions. The Green Grid has recently announced additional metrics to complement PUE, including Carbon Usage Effectiveness (CUE) and Water Usage Effectiveness (WUE), designed to help data center operators assess the sustainability of their data centers.

The Green Grid’s Free PUE-Related Tools to Data Center Operators
The Green Grid, which encourages worldwide industry collaboration, is actively working on dozens of strategic and tactical projects to improve data center resource efficiency. In addition to a library of white papers, The Green Grid has made the following PUE-related tools available free of charge to the data center community:

• Online Courses from The Green Grid Academy The Green Grid Academy has launched two award-winning self-directed online courses to help data center managers and operators get familiar with industry lexicon and solutions to everyday data center challenges, including instructions on using PUE in improving energy efficiency.
• PUE Reporting Database The Green Grid’s PUE Reporting Database is an online form that allows data center operators to report their own PUE, and compare it to other facilities across a variety of parameters and regions.
• PUE Estimator Online Tool The Green Grid’s PUE Estimator is an interactive online tool that allows data center operators to easily input their facility’s specific data to determine their PUE.