A couple of Google searches won’t overwhelm the power grid and make the lights go dim. But add together all of our networking activities — online queries, YouTube videos, Tweets, emails, Skype chats, Web conferences, project management, cloud-based collaboration, invoicing and more — and we’re looking at a heavy, rapidly expanding and very real energy and carbon footprint for our virtual interactions.

In just 10 years, according to one estimate, the world’s data centres could be spewing out more greenhouse gases than the global airline industry. And even with more efficient servers, the power drain of data centres is immense. Over the course of a year, a single rack of servers can use as much energy as a car driven from one end of the US to the other … 300 times.

With energy costs expected to go nowhere but up in years to come, that spells a big problem for internet service providers, information technology companies and every business — from Mom-and-Pop- to IBM-sized — that relies on computer networks to operate. In fact, the US Department of Energy predicts that, by 2012, a data centre’s lifetime energy bill will exceed the cost of building the data centre itself. (And data centres aren’t cheap; Amazon.com reportedly spent some $100 million on its Oregon facility.)

So what are companies doing to tame their data-related energy appetites and prevent their computing from melting the planet?

Cisco, one of the leading firms taking action in this area, has a number of initiatives in place. In addition to being a contributing member of the Green Grid consortium for energy-efficient data centres, Cisco has rolled out programmes to reduce both its own and its customers’ computing energy footprint. One of its focus areas is virtualisation, which can reduce electricity use by as much as 70 per cent by cutting down on the number of components needed in a data centre. Reducing the amount of equipment also helps to lower cooling costs.

Cisco is also installing smart power strips that will let it remotely shut down unused equipment across the network, an improvement that could cut energy consumption by 20 to 30 per cent.

Dell, too, is putting the spotlight on virtualisation as a way for customers to reduce their data centre energy bills. Its in-house efforts in that area last year helped it reduce its own data centre power consumption by the equivalent of a year’s worth of energy for 2,000 households. Green IT practices have also enabled Dell to “indefinitely postpone” the need to build a new data centre to support its operations.

Siemens’ “Transformational Data Centre” approach involves not just virtualisation but automation and active energy management as well. The system uses fluid dynamics modelling, for example, to reduce recirculation of hot or cold air to spaces where it’s not needed. Automation is implemented to streamline every aspect of data centre operations from configuration to problem resolution. Siemens says the strategy can cut energy consumption by 30 to 50 per cent. Following that approach in-house, it’s pared down its number of data centres in Germany from 100 to 30, while reducing power use by 80 per cent.

IBM has pursued a similar path with its “Enterprise Data Centre,” which it implements in-house as well as for customers … critical for a company that has more than 450 data centres worldwide under its control. In addition to virtualisation and other green IT strategies, it also relies heavily on monitoring and measuring — including real-time thermal monitoring — to identify efficiency trouble spots and save energy.

However cutting-edge their technologies, however, companies with data centres can’t achieve truly green computing unless they’re also getting their energy from greener, more sustainable sources. That’s an area in which some companies, no matter how efficient their IT facilities, have gotten into trouble. Facebook, for example, has been in Greenpeace’s crosshairs this year for touting the uber-efficiency of its new data centre because the energy powering it comes from coal-heavy sources.

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• The case for the EU’s ‘green’ data centre code
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