Jonathan Koomey, a data center energy expert and consulting professor in the civil and environmental engineering department at Stanford University, released a new report Monday estimating the amount of servers and electricity consumed by Google, and how energy-efficient those custom servers are.
Since Google doesn’t reveal the number of its servers and total electricity use—for competitive reasons, it says—Koomey estimates that in 2010, Google had 900,000 servers—more than double the estimated amount in 2005—and used a total of 1.9 billion kilowatt-hours of electricity.
However, Koomey maintains that Google’s servers are incredibly efficient. According to his research, Google is responsible for less than 1 percent of the electricity used by the world’s data centers, even though the company provides 2.8 percent of the world’s volume of servers.
The main reason for this is because Google’s customized server design includes an on-board, lead-acid battery for each server to create a distributed backup power system. Most other data centers use a centralized backup system—such as a room full of generators or flywheels—but Google’s system has the potential to earn an energy-efficient rating of over 99.9 percent. Google also saves money and energy for its data centers by turning up the heat in its data centers to 80 degrees and eliminating chillers and cooling by using outside air and alternating hot and cold aisles.
Koomey crunched Google’s numbers in his search for the total amount of electricity consumption for data centers in 2010. Koomey consulted figures from the International Data Corporation, but since Google creates its own servers, its numbers aren’t included in IDC’s figures.
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