Accounting for nearly 1 percent of total power consumption in the UK alone, BT Group was faced with a dilemma: how to scale and roll out new services to take advantage of new market opportunities without overburdening its energy budget - and the climate.

"We do have a very huge carbon footprint," said Donna Young, BT Group's head of climate change. "How we mitigate against that is important as the number of customers using the networks increases." Seeking to reduce the energy costs of its IP networks, the British telecom developed plans for network rollouts with sustainable IT practices in mind, setting into motion an ambitious, companywide initiative to cut BT's carbon footprint by 80 percent before 2016, as compared against 1996 levels.

Building new efforts is not enough

But focusing on sustainability in new services would not be enough to achieve that vision. Significant efficiency gains, the company quickly realised, could best be obtained by reusing new ways of thinking about energy consumption in older environments.

"It was obvious that if we could take what we learned from the network build and transport it to our datacentres, we could make huge improvements in terms of energy efficiency," said Dave Needham, BT Group's head of datacentre strategy.

And so the BT datacentre team examined the chief energy-minded aspects of the company's IP network build-out strategy, assessed avenues for achieving requisite scale, and set about wresting inefficiencies from approximately 90 legacy datacentres on a targeted, site-by-site basis. The resulting 21st Century Network Data Center Project, which began in June 2004, is now the centrepiece of the company's strategy for fulfilling its carbon footprint mission.

According to Needham, 60 percent of the efficiency methodologies used in the IP build-outs have carried over to the retrofitting of datacentres, some of which were originally constructed in the early 1980s.

The two strategies that made the most difference

Two strategies in particular have had the most significant impact: a shift from forced- to fresh-air cooling, and a reduction in the number of power conversions employed across each infrastructure.

By knocking out walls between server rooms and hallways where possible, installing variable fans for fresh airflow, and tapping Britain's most abundant cooling asset -- its climate -- BT has already reaped 16 percent efficiency gains with its new approach to cooling. Moreover, by carrying alternating current (AC) as far as possible into its datacentres before transforming to direct current (DC) to power servers, BT has cut power-conversion energy loss by 12 percent.

Needham described the team's approach as a continual feedback-fuelled process of improvements. Adjustments are made, effects are measured, and the team redoubles its efforts to cut down energy consumption even further. When all is done, Needham expects BT's datacentres, which combined house approximately 11,000 server racks, to be 70 percent more energy-efficient.

A savings pool, and a test bed, too

Overall, the 21st Century Network Data Center Project has thus far resulted in savings of US$7.4 million in electricity costs, as well as a 60 percent reduction in the company's UK carbon footprint.

And the project is also turning out to be a proving ground for BT datacentres to come. "What we're also pursuing is a blueprint for a datacentre based on these core components. Any new build capability we do now, we introduce all of those things into this design process," Needham said, estimating that his team will deliver this blueprint for energy-efficient datacentres by September.

Young, who counts taking a leadership position on sustainable IT practices among the chief motivating factors behind BT's green tech push, concedes that advocacy is easier when the returns on investment are worthwhile.

"There aren't any altruistic companies out there doing things sheerly for the benefit of the planet and nothing else," Young said. "All of this has been done on a business-case basis."

But as colleague Steve Rayner, global head of datacentres, customer experience management, and end-user technology at BT, noted, awareness of the impact technology has on the climate is beginning to shift opportunities to those companies willing to make a change.

"You can attract business by changing your operations to be more green and more socially responsible, because a lot of companies measure their carbon footprint not only by what they directly consume when they're delivering services but also their suppliers and vendors, what energy they're consuming to deliver that as well," Rayner said. "I think there are opportunities in the market, and there will be more so around that in the years to come."

Time to revisit equipment and warranty standards?

The biggest benefit the 21st Century Network Data Center Project itself may have on the environment could come with work the BT Group has undertaken with the Green Grid, a consortium aimed at reducing datacentre power consumption industrywide.

Because what BT has found undertaking its 21st Century Network Data Center Project is that traditional standards in manufacturers' warranties could also benefit from some retrofitting.

"When you look at a traditional kit that goes into a datacentre, it has a warranty that says it must be kept cool at 22 degrees [Celsius, or 72 degrees Fahrenheit]," Young said. "And that was probably set around 1974, when we had magnetic tape, and we don't have magnetic tape anymore."

In BT's now fresh-air-cooled datacentres, temperatures climb as high as 35 degrees Celsius [95 degrees Fahrenheit] -- with no impact on performance. "We're not seeing the fault rates that would be expected," said Needham, who is also testing the effect of humidity beyond standardised ranges.

"If we can warm up the datacentres, we would save huge amounts of energy across the globe," Young added. "We're sitting on the Green Grid, pushing suppliers to reevaluate what they do, and we're getting traction. We're at a stage where they value our input because we are really pushing them to make significant changes."