Data centre power usage has expanded significantly less than expected – due to the economic crisis
Data centre power use has grown significantly less than predicted over the past few years, largely due to the 2008 economic crisis, according to a new study.
The study (PDF), carried out by Jonathan Koomey, a consulting professor in the civil and environmental engineering department at Stanford University, found that electricity used by data centres worldwide increased by about 56 percent from 2005 to 2010. This might seem a big increase, but experts had predicted energy use would double over this period.
In the US data centre electricity use grew by about 36 percent, according to Koomey’s figures.
Data centre electricity use doubled from 2000 to 2005 and an influential study by the US’ Environmental Protection Agency (EPA) predicted it to double again from 2005 to 2010.
Electricity used in data centres worldwide in 2010 accounted for about 1.1 percent to 1.5 percent of total electricity use, while for the US the figure was between 1.7 percent and 2.2 percent, Koomey said.
The EPA report to the US Congress had expected more power-efficient technologies would mitigate the growth in power consumption, but in fact the lower growth was due mainly to the recession, which limited demand for servers.
“This study’s reduced electricity growth rates… were driven mainly by a lower server installed base than was earlier predicted rather than the efficiency improvements anticipated in the report to Congress,” Koomey wrote in a blog post on Monday.
Rise of the cloud
The results may seem surprising at first glance, because of the boom in data centre-powered services during the period of the study – technologies such as social networks, streaming music, cloud-based applications and cloud-connected mobile devices.
However, cloud computing actually aids more efficient data centre usage, according to the study.
“Because cloud computing installations typically have much higher server utilisation levels and infrastructure efficiencies than do in-house data centers (with power usage effectiveness or PUE for some specific facilities lower than 1.1) increased adoption of cloud architectures will result in lower electricity use than if the same computing services were delivered using more conventional approaches,” Koomey wrote in the study.
During the course of collecting data for the report Koomey received figures from Google estimating the company’s data centre power usage at less than 1 percent of electricity used by data centres worldwide.
“To my knowledge, this is the first time that Google has revealed specific details about their total data centre electricity use (they gave me an upper bound, not an exact number, but something is better than nothing!),” Koomey wrote in the blog post.