Industry groups and government agencies from the U.S., Europe and Japan have reached a basic agreement on how to measure the energy efficiency of data centers, they are expected to say on Monday. The agreement is seen as significant because it establishes a common metric that different types of data centers, in different parts of the world, can use to report their level of energy efficiency. That could provide a yardstick for companies to assess the efficiency of their own data centers, and also to gauge the effectiveness of energy-saving techniques employed by other facilities. Orchestrated by the Green Grid, an industry consortium in the U.S., the agreement is backed by the U.S. Department of Energy, the U.S. Environmental Protection Agency, the European Union Code of Conduct and the Japan Ministry of Economy, according to a statement from the Green Grid.