The Business of PUE Measurement update from April 2009

puelevels

How accurate are your measurements of the energy efficiency of your data center? More companies are now tracking and reporting their efficiency using the Power Usage Effectiveness (PUE) metric popularized by The Green Grid. But not all PUE measurements are created equal, and  there's growing focus on the various ways to gather the data.

The Green Grid has outlined three levels of PUE measurement, based on the particulars of where and when measurements are taken, which are outlined in the chart above. The Basic, Intermediate and Advanced PUE ratings are defined by where the IT equipment power and total facility power measurements are taken, and how often the data is collected.

But The Green Grid has no plans to certify PUE ratings or act as a referee in disputes over scores or methodologies. “You’re not going to find a Green Grid energy assessor going out there, but we’ll help provide guidance, and provide a variety of tools and methodologies,” said Green Grid board member John Tuccillo. But other consulting firms are launching services around PUE measurements.

Raritan Inc. and EDSA Micro Corporation said last week that they have combined their data center power analytics solutions to help companies automatically calculate Advanced PUE ratings, which requires that energy  data be monitored and recorded continuously, down to the server level. The two companies said the collaboration is the first commercial service for tracking Advanced PUE metrics.

The Raritan/EDSA offering pulls real-time data values, continuously and automatically, to calculate PUE according to the guidance provided by the Green Grid. EDSA’s electrical power diagnostics solution tracks and measures energy used in a building’s electrical infrastructure, such as lighting, cooling and UPS, while Raritan’s energy management solutions measure the energy used by the IT equipment use at the server power cords. The offering was introduced at last week’s Uptime Symposium in New York.

"The Green Grid’s PUE creates a common reference point that makes it possible for data center operators to start making important assessments of their facilities, as well as their going-forward strategies for reducing energy usage. said Kevin Meagher, Chief Technology Officer at EDSA. "Data center operators no longer have to be in the dark about their energy efficiency.”