Green Grid Pushes PUE As Global Data Efficiency Metric

Sustainable IT industry group Green Grid is pushing for international government agreement on a framework for the measurement of data centre efficiency.

In a statement released this week, Green Grid said that representatives from the US Department of Energy, the European Union and the Japanese Ministry of Economy, Trade and Industry have agreed on a set of guiding principles for data centre efficiency metrics.

Consistent metrics for data centre efficiency

According to Tom Brey, IBM representative and secretary of the Green Grid, the eventual aim was to create consistent metrics around the world for data centre efficiency. “The Green Grid is working with organisations around the world to develop a clear and well-defined language for the way we communicate about energy efficiency metrics, which will give us a common measuring stick for all data centres regardless of their location. With that type of consistency, we can start driving behavioral changes in the industry,” he said.

The Green Grid is a consortium of IT vendors – including Intel, Microsoft and AMD – and end-users of IT, which aims to develop tools and approaches to help its members improve the energy efficiency of their data centres.

As part of the process, the Green Grid and the organisations concerned have agreed to support an existing metric for measuring data centre efficiency – Power Usage Effectiveness (PUE). PUE is a metric created in 2009 by the Green Grid that determines the amount of energy used by a facility and all the IT gear inside of it. A PUE score is a ratio of total facility power divided by IT equipment power. Ideally it should be less than 2 to 1; the closer to 1 to 1, the better.

PUE is “far from enough”

Despite the support for PUE, some data centre operators have questioned its usefulness. Writing for eWEEK Europe UK last year, Charles-Antoine Beyney, president of the Carinae Group and founder of the Tier IV data centre in Paris – called Etix DataCenter – said that metrics which include the entire life-cycle of the data centre should be developed.

“Although this scramble for PUE (power usage effectiveness) is essential in the short term, it is far from enough in the long run. It does not significantly reduce the carbon footprint resulting from data centre construction and energy consumption, however low this may be,” he said.

The Green Grid itself has also pointed out how that PUE is not always an applicable metric. Last July, the organisation said that PUE shouldn’t be used to compare the efficiency of data centres. “PUE is a relational metric,” said Vic Smith, EMEA data centre strategist at Dell, and a senior member of the Green Grid. “It’s not meant to be used as a comparison between data centres”.

Ahead of the launch of the iPad, environmental group Greenpeace released a report, Make IT Green: Cloud Computing and its Contribution to Climate Change, which used the launch of the Apple device as a jumping-off point to discuss the growth of cloud services and the energy-hungry data-centres behind them.

“At current growth rates, data centres and telecommunication networks will consume about 1,963 billion kilowatt hours of electricity in 2020,” the group said. “That is more than triple their current consumption and more than the current electricity consumption of France, Germany, Canada and Brazil combined.”