Google Inc. has disclosed publicly for the first time exactly how much electricity the companys massive computing resources consume, while laying out what it has been doing to limit carbon emissions.
Google said the total amount of electricity it used for its operations in 2010 was roughly 2,260 megawatt-hours. Using figures from a study made by Stanford University professor Jonathan Koomey, the company said this represents 0.01 percent of the world’s electricity.
And when divided into the 1 billion users of its Google Search, Gmail, Google+, YouTube and other services, the company said this means 2.26 kilowatt-hours per user every year – about the same amount of energy used by a 60-watt light bulb turned on for three hours.
The United State’s Energy Information Administration said an average American household in 2009 consumed 10,896 kWh of electricity, and the entire country consumed close to 4,000 billion kWh in 2007.
Until now, Google did not disclose its energy usage, viewing it as competitive information that indicates operating costs. This drew criticism from environmental watchdog Greenpeace, giving Google a score of «F'» for transparency in its Cloud Computing Report Card in April.
But Google, who said it will source 35 percent of its electricity from renewable energy by 2012 either by directly buying electricity from alternative energy projects or through utilities with power purchase agreements, said it has been doing its share in saving electricity over the years.
«We started the process of getting to zero by making sure our operations use as little energy as possible,» Urs Hoelzle, Google’s vice president of technical infrastructure, said on the Google Green blog. Mr. Hoelzle added that for the last decade, energy use has been «an obsession.»
‘Carbon-neutral’
By designing more efficient data centers, investing in renewable energy projects and purchasing carbon offsets, the California-based firm said it has managed to cut its carbon footprint, or the total greenhouse gas emissions it makes from providing its services, to zero since 2007, Hoelzle said.
Greenpeace did give the company a 36.4 percent index in its Cloud Computing Report Card, making it second only to Yahoo!’s 55.9 percent. The percentage was computed using the estimated electricity demand of a company’s facilities and the amount of renewable electricity being used to power them.
Last year, 25 percent of Google’s electricity use came from renewable sources, which it projects to be 30 percent this year.
The company began trimming its energy use by designing more efficient computer servers and the data centers that house them. Google focused on how they cool these high-performance computers, since data centers use almost half their energy cooling them.
By ensuring good airflow and using novel cooling systems like evaporating water, Google said it made data centers that use 50 percent less energy than typical data centers just by reducing the power used to cool computer servers to nearly zero.
In its report, InfoWorld said Google had a power usage effectiveness or P.U.E. score of 1.19. The ratio shows how much energy a data center uses for actual computing compared with how much is wasted on non-productive tasks like cooling. According to the Uptime Institute, a typical data center has an average P.U.E. of 2.5.
Aside from cutting energy use from the more than 30 data centers it owns, Google said the amount of clean power it has bought to power these facilities have continued to increase over the past few years.
Energy activities
Despite having the internet and computing as its core business, the company emerged as one of the most aggressive clean power project investors especially over the past two years.
As of June 2011, it had invested over $780 million into renewable projects and technologies, with around $700 million of that being invested this year. This resulted in 1.7 gigawatts in generating capacity from wind and solar, Mr. Hoelzle said.
Google also said it buys carbon offsets to compensate for the carbon emissions coming from the other 65 percent of its energy consumption made by fossil fuel-based power plants. A carbon offset represents a tradable commodity equivalent to a reduction of a metric ton’s worth of carbon.
