Power Usage Effectiveness (PUE) is a metric developed by The Green Grid to measure data center efficiency. PUE is the ratio of the total amount of power used by a data center to the power delivered to IT equipment. A ratio of 1.0 would indicate a perfectly efficient data center in which all of the power coming into the facility is delivered to the IT equipment with none of the power used to cool or light the room and none lost in transmission to the IT equipment. Most data center managers target a PUE of less than or equal to 1.5, or 1.4 for new data centers.
The formula to calculate PUE is:
PUE = Total Facility Energy / IT Equipment Energy
Establishing the total facility energy is typically done with a utility meter. However, installing a “shadow meter” allows data center managers to record daily measurements of the total facility power usage rather than having to wait for a monthly utility bill.
Calculating energy consumed by IT equipment in the data center is done by summing up the power readings at the power distribution units (PDUs) that distribute power to the IT cabinets. This data may also be captured by remote power panels (RPPs), uninterruptible power supplies (UPS), or intelligent rack PDUs. If the floor PDUs or RPPs are not instrumented, many vendors offer aftermarket branch circuit meters with split-core current transformers that snap into existing panels. This data can be recorded manually or automatically collected over a network and fed into an energy management or power monitoring solution that can automatically trend and report on PUE across all your data centers.
Data Center Infrastructure Management (DCIM) software automatically calculates PUE in real-time and consolidates that information into actionable reports to enable data center managers to save power and money while driving green data center and data center sustainability initiatives.
Want to see how Sunbird’s world-leading DCIM software makes it easy for you to automatically calculate PUE in real time across all sites? Get your free test drive now!