The United States of America, European Union, and Japan reached an agreement on guiding principles for data center energy efficiency metrics, according to an announcement made on February 2, 2010, by several organizations.

The statement read, “As business demands and energy costs for data centers rise, owners and operators have focused on the energy efficiency of the data center as a whole, frequently using energy-efficiency metrics. However, the metrics are not always applied clearly and consistently at a global level. To address these inconsistencies, a group of global leaders met on February 2, 2010, to agree on data center energy-efficiency measurements, metrics, and reporting conventions.”

The groups agreed that
  • Power usage effectiveness (PUE) using source energy is the preferred energy-efficiency metric.

  • Industry should improve the IT measurement capabilities to ultimately enable taking the measurement directly at the IT load (e.g., servers).

  • For a dedicated data center, total energy measurement should include all energy sources at the point of utility handoff. For data centers in larger buildings, total energy should include all cooling, lighting, and support infrastructure, in addition to IT load.
In addition to PUE, the bodies recognize the necessity of other metrics expressed in the desired outcomes.

Organizations represented were the U.S. Department of Energy’s Save Energy Now and Federal Energy Management Programs, U.S. Environmental Protection Agency’s Energy Star program, European Commission JRC Code of Conduct, Japan’s Ministry of Economy, Trade and Industry, Japan’s Green IT Promotion Council, and The Green Grid.