U.S. Department of Energy - Energy Efficiency and Renewable Energy
Advanced Manufacturing Office – Saving Energy in Data Centers
Data Center Industry Leaders Reach Agreement on Guiding Principles for Energy Efficiency Metrics
February 1, 2010
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. To address these inconsistencies, a group of leaders from across
the industry met on January 13, 2010 to agree on data center energy efficiency
measurements, metrics, and reporting conventions. Organizations represented
were the 7x24 Exchange, ASHRAE, The Green Grid, Silicon Valley Leadership
Group, U.S. Department of Energy's SaveEnergyNow and Federal Energy Management
Programs, U.S. Environmental Protection Agency's ENERGY STAR Program, U.S.
Green Building Council, and Uptime Institute.
The following guiding
principles were agreed to:
- Power Usage Effectiveness (PUE) using source energy
consumption is the preferred energy efficiency metric for data centers. PUE is
a measurement of the total energy of the data center divided by the IT energy
- When calculating PUE, IT energy consumption should, at a
minimum, be measured at the output of the uninterruptible power supply (UPS).
However, the industry should progressively improve measurement capabilities
over time so that measurement of IT energy consumption directly at the IT load
(i.e., servers) 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 a data center in a mixed-use building, the
total energy will be all energy required to operate the data center, similar to
a dedicated data center, and should include IT energy, cooling, lighting, and
support infrastructure for the data center operations.
guidance is meant to help the industry have a common understanding of energy
efficiency metrics that can generate dialogue to improve data center
efficiencies and reduce energy consumption. Member organizations are committed
to applying and promoting these guidelines to their programs.
task force, consisting of the organizations listed below, has been created to
further refine these metrics and to identify a roadmap for the future. The
group also aspires to address IT productivity and carbon accounting in the
you are a member of one of the groups listed below, please contact them
directly for further details.
- 7x24 Exchange: http://www.7x24exhange.org/eemetrics.html
- ASHRAE: http://tc99.ashraetcs.org
- The Green Grid: firstname.lastname@example.org
- Silicon Valley Leadership Group:
- U.S. Department of Energy SaveEnergyNow Program:
- U.S. Environmental Protection Agency's ENERGY STAR Program:
- U.S. Green Building Council: email@example.com
- Uptime Institute: http://www.uptimeinstitute.org