PUE: The Green Grid metric for evaluating the energy efficiency in DC (Data Center). Measurement method using the power demand

PUE (Power Usage Effectiveness) is a metric developed by the Green Grid widely accepted for measuring energy efficiency in Data Centers (DC). In summary, this metric relates all the energy consumed by the DC by that consumed by the servers. "Where to measure " will depend on the particular characteristics of each facility. "What" and "how" to measure is the goal of this paper. In its most simplified form, PUE is the ratio between annual energy consumed by the DC and annual energy consumed by the servers. There are recommendations as to take measurements in shorter time periods (monthly, weekly, daily, etc.), whose results may show the evolution of efficiency with time and give greater understanding of the behavior of the DC to take corrective actions. In this work a measurement method will be treated based on the record of the power demand integrated in 15 min or 1 h periods, due to the ease of using standard measuring equipment to obtain it, the reliability and accuracy of data and usefulness of their results.