Why monitoring PUE continuously is important

In "Just implementing technology will not solve your energy problems!" we covered some of the key influences affecting energy costs and power consumption. We concluded that monitoring was one of the foundation stones to be implemented as an important tool in addressing the energy issue.

Monitoring of data enables statistical and historical analysis of how energy is being consumed, which is a basic requirement when for helping in the management decision process.

The most widely accepted energy metric in the data centre is Power Usage Effectiveness (PUE) which helps define the relationship between the total of power consumed by the data centre or IT ( Total Facility Power - TFP) and total amount of power used by the IT equipment only ( IT Equipment Power - ITEP).

Although its use is becoming more common place there are substantial problems with PUE, but it’s simplicity has encouraged adoption, but with its simplicity applying the metric requires considerable understanding of the environment it has been derived from. These issues are covered in detail on our website (PUE issues)

Fundamentally PUE is a point in time measurement of how TFP and ITEP are interacting and depict the energy efficiency at the specific point in time the measurement is taken. This means that depending on many different factors, including time, workload and even the weather, PUE may be different, for the data centre.

As PUE can vary in this way its value is enhanced by reviewing it continuously and assessing how it changes over time. This will establish a profile of how your data centre varies in energy efficiency over time and enables you to understand peaks and troughs in consumption and efficiency.

Currently IT infrastructure does not give up the information needed to drive effective PUE measurements easily and the solutions necessary for aggregating the energy related data can be costly. However, there are some good low cost tools available today that can lift an organisation out of the Excel spreadsheet era helping solve both the energy issues and carbon footprint reporting.

With the industry focussing more on PUE as its flagship measure and Gartner predicting that eighty percent of data centres (80%) will be reporting continuous PUE by 2015, prices may fall as tooling becomes commoditised and more vendors enter the market.

Dimension 85 specialises in Data Centre Energy Efficiency Management.  You can contact Dimension 85 on the Dimension 85 website.