New age of lower PUE ratings brings renewed industry focus to harmonics

The Green Grid, a global consortium of organisations dedicated to advancing resource efficiency in data centres, has announced the release of a new white paper focusing on data centre power system harmonics.

The success of many in the data centre industry in improving PUE ratings has seen an increase in interest in reducing harmonics - once viewed as a problem solved through improved computer components. However, for those with existing low PUE-rated data centres, harmonics are a critical area for further reducing inefficiencies, even when the amounts of voltage distortion being considered are a relatively small.

Announced today at the The Green Grid’s EMEA Forum in Brussels, the new report is a deep analysis of the impact of harmonics within a uninterruptible power supply (UPS) and distribution to equipment further downstream in the data centre, including transformers and IT equipment PSUs.

The report presents an overview of harmonics, including what they are, the difference between harmonic voltage and current, what causes harmonics, and what problems harmonics can cause. It also goes on to discuss what levels of harmonics can be tolerated and under what conditions, and suggests diagnostic and mitigation methods, as well as outlining how harmonic voltages and currents can affect data centre power distribution system efficiency.

Ian Bitterlin, EMEA Technical Work Group Chair at The Green Grid, who is presenting on the paper today at the EMEA Forum says: "There can sometimes be a danger of harmonics being overlooked when it comes to data centre efficiency, possibly because it can be perceived as a complex subject to understand. However, it has a major part to play in the health and effectiveness of data centres, and it is important for organisations to begin analysing whether their PSUs are affecting the power and efficiency of their systems.

"It is of particular importance to data centre owners who are advanced in their energy efficiency programmes. For example, when we are talking about taking a data centre's PUE down from 1.3 to 1.2, harmonics can be a sizeable contributor to success."

The Green Grid has released a number of metrics and educational guides to help organisations make their IT systems environmentally efficient, and releasing this latest paper about the subject of harmonics is the natural next step for The Green Grid ‘s efforts to raise awareness of many more aspects of the data centre to ensure better practice.