Google comes clean on energy use

Google disclosed how much electricity it uses as a company for the first time today when the Internet giant described how it has cut carbon emissions.

Google said today that it consumes 2.26 kilowatt-hours per user per year, about the same amount of energy as running a 60-watt lightbulb for three hours. By investing in renewable-energy projects and purchasing carbon offsets, Google has cut the greenhouse gas impact of providing its services to zero, Google's vice president of technical infrastructure, Urs Hoelzle, said on the Google Green blog.

The total amount of electricity Google uses from its operations is almost 2,260 megawatt-hours, which is 0.01 percent of the world's electricity. That's about one quarter the yearly output of a nuclear power plant, according to The New York Times, and slightly more energy consumption than the country of Laos, according to The Guardian.

Until now, Google has resisted calls to disclose its energy usage, drawing criticism from environmental watchdog group Greenpeace. Energy usage of cloud-computing companies has been seen as competitive information because it provides an indication of operating costs. But Google has been vocal about how it has improved the efficiency of its data centers and its corporate objective of being carbon neutral.

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By using custom-designed hardware and software, Google's data centers use about half the energy of typical data centers. It has also hundreds of millions of dollars in renewable energy, resulting in 1.7 gigawatts in generating capacity from wind and solar, Hoelzle said today.

Last year, 25 percent of Google's electricity was from renewable sources, which it projects to be 30 percent this year and 35 percent next year.

Google is investing directly in large-scale wind and solar projects to boost the amount of renewable energy it buys. It also has a program of purchasing carbon offsets which represent investments in renewable energy or other projects which reduce greenhouse gas emissions.

Google has also sought to lower carbon emissions from its employees' transportation with shuttles and providing electric-vehicle charging stations on its campus. Between its efficiency measures and renewable energy, Google has been carbon neutral, said Hoelzle.

The carbon footprint of doing 100 searches--not including the energy used by the computer accessing a Google Web service--is the same as running a laptop for about an hour, Google said. Yesterday, Google released an analysis which showed that its Gmail service consumes less energy than on-site e-mail servers, particularly for small companies.