Last year when Wendy Cebula was shopping for a new vehicle, energy efficiency and lower emissions topped her list of requirements, along with four-wheel drive (her family lives on a hill). Cebula, then CIO at VistaPrint, a $US152 million online supplier of custom print services, eventually chose a hybrid model instead of the traditional SUV. Even though she didn't think the incremental savings on petrol would make up for the higher sticker price, she says "it was the right thing to do as a human being".

But as a corporate executive, Cebula, now VistaPrint's COO, can't lead with her heart. The right thing to do is whatever enables the business to grow. Those decisions come down to dollars and sense, not what's best for the planet. But every now and then, the two converge.

In late 2005, Cebula noticed her data centre's costs were growing. The company, whose operations are almost completely automated, was adding 100,000 customers a month — and growing at nearly 60 percent a year. There was no sign the demand for data necessary to serve those customers would stabilize. When Cebula and Aaron Branham, VistaPrint's vice president of technology and operations, dug into data centre operations in detail, they discovered that energy costs were rising significantly.

If there were some way to lower power costs or increase energy efficiency, they could cut expenses. To Cebula, an avid recycler who tries to impart environmental awareness to her kids, doing so would be a double win. She could do "what's good for the environment and what's good for the bottom line", she explains.

Until recently, the environmental impact of the data centre was largely ignored. But today, energy experts estimate that data centres gobble up somewhere between 1.5 percent and 3 percent of all electricity generated in the United States. Market research company IDC estimates that companies spent $US26.1 billion to power and cool servers worldwide in 2005. That's more than was spent to power all the commercial buildings in 17 states — from Delaware to Florida and west to Texas, according to the Department of Energy's most recent energy consumption survey.

And that's not all. According to the Uptime Institute, a consortium of companies devoted to maximizing efficiency and uptime in the data centre, more than 60 percent of the power used to cool equipment in the data centre is completely wasted. In fact, notes a recent study by the group, energy costs have replaced real estate as the primary data centre expense. "Data centres that used to cost $US10 million now cost $US100 million," says Jonathan Koomey, staff scientist at Lawrence Berkeley National Laboratory. "That kind of expenditure gets C-level attention."

It's garnered government interest too. A federal law enacted in December compels the US Environmental Protection Agency to examine power consumption in data centres, evaluate what technology manufacturers are doing to increase energy efficiency and determine what incentives could convince companies to adopt more energy-efficient technology. The European Union is studying the level of carbon emissions from computer equipment. Down the road, local and federal governments in the United States and abroad may end up penalizing organizations that operate inefficient data centres, according to Rakesh Kumar, Gartner research vice president.

The combination of financial, environmental and legislative pressure will force IT organizations to develop cleaner data centres, says Kumar. By 2011, Gartner predicts, a quarter of new data centres will be designed for maximum energy efficiency and minimum negative environmental impact. But what that means may vary by organization. "There's no generally accepted, standardized way to build a green data centre," says Kumar.

At VistaPrint, becoming green has proven easier than Cebula thought. The company bought more energy-efficient servers and improved utilization in its primary data centre in Bermuda, steps that have reduced energy usage by 75 percent. As a result, the company expects to save nearly half a million dollars over three years and estimates it will reduce its output of carbon dioxide emissions by several hundred tons in this year alone. That's equivalent to taking more than 100 cars off the road for a year.

VistaPrint also decided to locate a new data centre in Canada, where hydroelectric power — a renewable energy source — keeps power costs stable and has potential to lower VistaPrint's electricity bills by another 70 percent. "We were able to reduce our footprint at a time when it was very important to us financially," says Cebula. "And it's much more green."