IT is responsible for three to four per cent of the Tesco total carbon footprint, but it is also the key to reducing greenhouse gases, according to Mike Yorwerth, the company's group technical director. "

Yorwerth said that IT was getting its house in order, so that it could enable change across the organization.

Most of the supermarket's energy consumption -- about 75 per cent - is in its shops through tills, servers, TVs and PDAs. "It is really hard to manage that," Yorwerth said.

Data centers only account for 11 per cent of energy consumption and emissions, but here the driver for efficiency is as much getting sufficient power to run its growing operations as it is to meet the edict from the company's board to create a sustainable organisation.

Tesco has applied a Six Sigma-type methodology to greening its IT, which comprises of defining, measuring, analysing, improving and control. This has resulted in a series of initiatives that can have a major impact on the organisation's environmental footprint, as well as longer term strategic planning, Yorwerth explained.

For instance, Tesco has 30,000 tills in the UK that traditionally have been left on 24 hours a day, seven days a week. The company has stared switching off unused tills overnight.

But Yorwerth said the move to switch off unused equipment has met with resistance from some IT staff. "The big challenge is for guys in the operations department. There is a lot of fear in it about switching things off," he said.

In its data centers, Tesco is embracing virtualization, particularly for its Windows Server environment. "Windows servers are very poorly utilised," Yorwerth said, which raises the potential for significant savings.

The retailer still has considerable work to do on restructuring its current data centers to be more energy efficient. "There is a lot we can do by having a look around the data center," he said. "We don't have hot and cold aisles, for example."

Energy efficiency on the desktop is being driven by Active Directory policies said Yorwerth.

Tesco has put in place a policy that new systems must be more energy efficient than those they replace, and it is building a green scorecard for use during procurement.

For Yorwerth the big challenge is what role IT can play in reducing the 96 per cent of the company's carbon emissions that it is not directly responsible for. As part of this drive, the retailer is pushing its suppliers, such as IBM and CA, to develop the sort of management tools used to control IT systems for non-IT kit.

One such initiative involves developing a centralised building management system, which could potentially save up to 16 per cent of thier total carbon footprint. In addition, improved routing of telemetrics in its logistics and delivery service for its online store, tesco.com, could reduce the carbon footprint by a further 10 per cent.

Above all though Yorwerth said, "Green IT helps us focus on efficiency, it helps the business be more flexible and agile."

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