Thin client computing has been around for a decade, but its ability to shave some money of electricity bills is an increasingly appealing part of its feature set. Stephen Ennis, technical director at Avnet Technology Solutions, said that a Sun Ray client sitting by a user's desk would use 5 per cent of the energy of a traditional PC. He is, however, realistic about what this means to customers.

“There is long list of advantages in moving to thin client but ultra-low power consumption is not a primary one,” Ennis said. “But when it comes to putting together the commercial argument, power savings and reduced CO2 omissions are something that people are paying more and more attention to.”

Another compelling statistic is that an up-and-running Sun Ray thin client uses half the power of a PC in standby or sleep mode.

“The point about this type of saving is that it may not amount to much when you look at single machines, but if you have an estate of hundreds of PCs it becomes quite significant,” Ennis said. “The main thin client benefits come from centralised infrastructure that is easier to manage, but you quickly get to the point where you are also saving substantial amounts of money.”

He said one of the big changes in the market was that customers were much more aggressive about seeing a return on their investment.

“Anything they buy has to pay for itself and the expectation of a return has moved from three years to 12 months,” Ennis said. “If you are refreshing 100 desktops, then power-saving suddenly becomes an important factor in achieving that timeline.”

Virtual desktops are another trend, a follow-on to server virtualisation that has far-reaching benefits for organisations. Once again, power saving is among them.

Mark McKeon, country manager with HP, points out that the basic principle switches the focus to an area of the infrastructure where power efficiency is at its best.

“Virtual desktop infrastructure takes power consumption away from the desktop,” McKeon said. “Everything is run from Blades servers in the data centre and benefits from the power and cooling savings that are being made in there.”

While he recognises that the refresh cycle inmost companies has been put on hold as they battle their way through the downturn, he argues that when the upgrade cycle comes around again, organisations should look at a radical infrastructure shift.

“People shy away from “rip and replace'‘ investments but if they look at designing a strategy from scratch, they should centralise in the data centre because that's where the big wins are to be found.”

Patrick Irwin, senior product marketing manager at Citrix, said desktop virtualisation and thin client computing were all part of IT centralisation strategies that reap many rewards, mostly around IT management and more efficient service deliver. But energy-saving is also important.

“You can cut power consumption by up to 90 per cent if you use the thin client model,” Irwin said. “And centralising all applications and data for delivery and maintenance can facilitate overall energy-saving efforts. Intelligent server provisioning and load management can ensure that only the hardware that is needed to meet user requirements is actually being used.”

A recent survey of chief information officers, conducted by Citrix, suggests that desktop virtualisation is also creeping up the agenda.

Around 36 per cent of the world's organisations are already evaluating or even trialing the technology. Digging deeper into why, energy efficiency was ranked sixth of six reasons to virtualise the desktop.

Benefits like fast desktop deployment and remote access from any device were seen as much more important.

“Power usage is part of the desktop virtualisation discussion in terms of costs savings but it's not central to it,” said Irwin.

Energy savings sweeten the virtual path

Virtualisation has been the IT buzz word for the best part of five years, with the move to virtual machines in the data centre leading to a radical restructuring of IT service delivery.

The process of consolidation to an environment where one physical server supports at least eight virtual machines has seen a massive reduction in the size of server farms, with fewer racks running on a smaller footprint. Although it might not be a main objective, a side benefit of virtualisation is power efficiency.

“When you look at the scope of a virtualisation project, it's usually about refreshing servers without having to buy new ones,” said Joe Molloy, director at IT Force. “The driver is never about energy efficiency but it becomes a welcome part of the journey.”

Gartner calculated that a server typically costs a $400 a year to power. So reducing an environment by 20 servers immediately brings savings of $8,000.More servers also demand more cooling and additional electricity costs of around 125 per cent according to EMC.

VMware has calculated that moving an application on to a virtual machine can typically save €237 a year in cooling and another €189 per year in electricity.

This is a fundamental change. The typical approach to rolling out a new application to a business was to buy a new server to host it. Over time the data centre or comms room would suffer ‘server sprawl' where a proliferation of boxes would become a drain on resources and difficult to manage.

Not only is it a mess, it's inefficient. Around 30 per cent of a server's peak electricity consumption happens when it is sitting idle which is about 80 per cent of the time.

According to research by EMC, a typical server runs a single application using around 400Wof power. With ten physical servers that would become 4000W.Avirtualised server hosting ten applications on a single machine is a much efficient, with each application effectively using just 40W.These incremental savings can become very significant depending on the scale of the business.

Taking this to an extreme is the concept of cloud computing, where all the infrastructure and applications are hosted in a virtual date centre and delivered back to the business by a third-party service provider. Everything becomes someone else's problem, including utility bills.

Aidan McCarron is managing director of Dediserve and happy to take infrastructure and applications off his customer's hands. He is a cloud based service provider running 2,000 virtual servers out of a Dublin data centre.

“Energy-efficiency is a selling point in what we do,” he said. “I meet a lot of customers running ten or 20 servers in their comms room. We reduce it to two servers on our racks, saving them a lot of money on power as well the physical space.”