Summary of PUE

Having considered PUE as a metric and looked at some of the data centre characteristics that can influence the calculated value, there are definite strengths to the metric – even if its billing as the one-stop energy efficiency calculator is potentially misleading.

So, how can you make the most out of PUE for your business?

PUE's variable nature and susceptibility to differences and changes in occupancy, workload, location and technological maturity, mean that it is not a suitable metric for comparisons. Unless it has been fully validated against these factors it is not recommended for assignment to any external marketing value and should only be used to help understand how efficient any given data centre is.

This places it firmly in the realm of a strategic management metric, a role to which it is highly suited. When used effectively it can also provide a tool for tactical analysis and monitoring change. Regular electrical measurement and data centre energy efficiency assessments provide the methods necessary to ensure that PUE is correctly managed. Furthermore, electrical measurement of the TFP and ITEP at regular and consistent intervals will provide the technical data necessary to enable variances and trends in the PUE to be recognised and acted upon. A target PUE of one (1) should be considered as the optimum value.

There are many other metrics that should be considered to help enhance the productivity and reduce the energy consumed per unit of operational work in a data centre. Assessment plays a large role here, as it will enable you to identify and prioritise the areas and aspects of the data centre that require attention and investment in order to improve energy efficiency and reduce long-term PUE.

To achieve maximum commercial benefit and increased asset utilization, it is best to engage in a long-term approach to energy efficiency. A programme of assessment, combined with tools like Assessor, can help businesses plan their long-term IT and energy efficiency strategies.