Educating end users on the carbon cost of electronic storage helps promote change.

Michelle Erickson doesn't really want to talk about how Citigroup has saved energy in its data centers, or how it is cutting power consumption for thousands of PCs. Everyone talks about that, says Erickson, initiative director for the global sustainable IT program at Citigroup. IT's role in sustainability is much broader. "We think about how Citi can reduce IT's environmental impact and then how IT can reduce Citi's environmental impact," she says.

"Michelle and the folks she works with are relentless at trying to understand the dynamics, get the data right... and treat everything as a system," says Howard Rubin, CEO of Rubin Worldwide, which tracks global technology trends for clients -- including Citi.

That's not to say that Citi hasn't gone for the "quick hits" by pursuing data center consolidation, virtualization, desktop power management and thin clients. But Citi has also created a program to aggressively market the benefits of virtual servers to individual business managers, who can save 40% to 60% per month in IT chargeback costs. "We have a whole marketing campaign to go out to the businesses and show them how it saves money," says Scott Key, director of server optimization for Citigroup's global operations and technology group.

Erickson oversees all of Citi's green IT efforts as chairwoman of the Sustainable IT Subcommittee, which pursues an integrated, big-picture approach to green IT in areas ranging from paper substitution to power management. For example, when Citi made a push into electronic statements to reduce paper and mailing waste, it factored increased IT costs into the equation. And it brokered a deal with the business units to move to power management for PCs and thin clients so that the real-estate group would reap the benefits on its electricity bills. "It's easy to do these things siloed. They look at the interactions between the pieces. That's the difference," says Rubin.

Erickson has made educating Citi's employees about green IT a priority. "It's very difficult for the average employee to understand the IT complexity and engineering that goes into everything," she says. For example, storage requires considerable power and cooling, so Citi has been informing users about the carbon cost of their electronic storage while encouraging them to delete unwanted files and avoid large file attachments. Those types of cultural and behavioral changes are 80% of the job, says Erickson.

Citi is in midst of consolidating within its data centers, virtualizing servers at rate of 100 servers per week -- with a 73% reduction in power demand for each. It's also consolidating its data centers from 54 to 24 by 2010. By decommissioning servers, virtualizing and moving to more energy-efficient data center designs -- such as its new LEED Platinum-certified data center in Frankfurt -- it expects to increase efficiency by 30%.

Some efforts have required education, but Erickson has the full support of Citi's top management. "Everyone recognizes that it's the right thing to do," she says.

Next: No. 5: PricewaterhouseCoopers to open a new high-voltage data center

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