Google: ‘The World’s Most Efficient Data Centers’

Google today disclosed details of its data center energy usage, confirming that it operates some of the most efficient facilities in the world. Google said it is averaging a Power Usage Effectiveness (PUE) rating of 1.21 across its six company-built data centers, and one of its facilities is operating with a PUE of 1.13, the lowest ever published and just above the “perfect” efficiency score of 1.0.

“Today we are operating what we believe to be the world’s most efficient data centers,” Google says. “Through these efficiency efforts we save hundreds of millions of kWhs (kilowatt hours) of electricity, cut our operating expenses by tens of millions of dollars, avert the emission of tens of thousands of tons of CO2, and save hundreds of millions of gallons of water.”

The typical enterprise data center is estimated to have a PUE of 2.0 or higher, and the lowest claim in our travels here at DCK is a PUE of 1.28 for Sun’s data center in Santa Clara, Calif. Compare that to this chart tracking the PUE at the six Google-designed data centers that have been in operations for six months or longer. The PUE number is on the left axis:

“We reduced the energy-weighted average overhead across all Google-built data centers to 21% versus the average of 96% reported by the EPA,” Google says in a new section of its web site dedicated to data center efficiency. “In other words, compared to standard data centers we’ve reduced the overhead by more than fourfold. To our knowledge, no other large-scale production data center has ever operated as efficiently. In fact, one of our data centers is running at an even lower overhead of only 15%, a sixfold improvement in efficiency.”

The company also adds an interesting metric. “In the time it takes to do a Google search, your own personal computer will use more energy than we will use to answer your query.”

Google has become known for its secrecy about its data center operations. The company’s disclosure of its PUE data comes at a time of increased information sharing about energy efficiency within the industry. Digital Realty Trust (DLR) has begun publishing the PUE information for its facilities, and more than 200 data centers are now participating in a data-sharing project with the U.S. Environmental Protection Agency. Google’s chief rival, Microsoft, has also been actively sharing information about its use of the PUE metric.

PUE is an emerging standard promoted by The Green Grid and others in the data center industry to provide a consistent way to measure the ratio of power delivered to IT equipment versus the total amount of power used by the facility. PUE allows data center managers to calculate how much power is driving the actual IT equipment versus non-IT elements such as cooling and lighting.

Continued on next page

Get Daily Email News from DCK!
Subscribe now and get our special report, "The World's Most Unique Data Centers."

Enter your email to receive messages about offerings by Penton, its brands, affiliates and/or third-party partners, consistent with Penton's Privacy Policy.

About the Author

Rich Miller is the founder and editor at large of Data Center Knowledge, and has been reporting on the data center sector since 2000. He has tracked the growing impact of high-density computing on the power and cooling of data centers, and the resulting push for improved energy efficiency in these facilities.

Add Your Comments

  • (will not be published)


  1. I'm excited to see Google take such a strong approach to promoting greater data center efficiency. But, I think what's lost in this post is one of the most inherent issues with the efficiency of a data center to begin with: facility level power distribution. This is, however, called out on Google's website (, saying, "Up to a third of the total energy consumed by a typical server is wasted before reaching the computing components. The majority of these losses occur when converting electricity from one kind to another. The power supply, which converts the AC voltage coming from a standard outlet to a set of low DC voltages, is where most of the energy is lost." While technologies like "evaporative cooling techniques" are certainly important in taking excessive heat, by fixing the problem at the root - inefficient electric distribution - you can generate less heat in the first place (which means less to cool). This occurs because, as Google notes, there are conversions (AC to DC), as well as transformations (higher voltage to lower voltage), that need to take place in a data center, which create excess heat at each point of change. With AC power distribution you are looking at 5-7 conversions and transformations, opposed to 2 with DC power distribution - reducing energy consumption anywhere from 15-50%. When it comes to energy efficiency in the data center, I'm as big a fan as anyone of unique and inventive technologies, but if you simply start at the source (electricity), you may be surprised how far you'll get (

  2. carl m

    It is interesting to me that Google does not highlight to the media the infrastructure in place that makes a PUE of 1.12 possible? A data center having unlimited alternative power should not set a standard for all others to follow (for PUE purposes only). Without the assistance of alternative power, a PUE 1.12 is impossible to achieve. SUN also claims a low PUE and my best bet would be that they have alternative power available too. In the upcoming year(s) I hope to see EPA separate bio fuels from alternative power in PUE calculations. I certainly looked into a 2MW PV grid but unfortunately (in my area) there is not the space.

  3. Lenny

    All, I am currently running large commercial data centers with a PUE of less than 1.3. When the infrastructure becomes more fully loaded I expect it to drop to 1.26 - 1.28. This is in an large co-location site with out containers all built with off the shelf products. I am currently implementiong some free cooling and expect to drop the PUE to an annualised PUE of around 1.15. This is without alternative energy forms. I see googles / mircosofts numbers being quite reasonable and easy to achieve without spending big on infrastructure. Going green does not means spending big dollars, it means spending your dollars in the right areas.