Metrics for energy efficiency assessment in data centers and server rooms

The energy consumption of centralized IT-equipment and data centers has been a fast growing topic over the past few years. It is widely recognized that a number of effective measures exist that in many cases would allow energy savings of 20-60% or even higher. Following the motto “You can´t manage what you don´t measure.” Energy efficiency metrics are typically used for benchmarking the energy consumption of single products or systems, hence covering equipment or facility-level. The major - not yet sufficiently resolved - challenge is the definition of the “useful work” provided by a data center. Recently developed concepts to further address service related energy consumption will be discussed in the paper. Central criteria and options for further development will be addressed.