The company, which will say only that it has between 10 and 100 data centers, has used software to create a map of the world that aggregates 35 factors, such as power costs and climate, to determine the best places to build. The map is a living artifact that changes with world affairs, utility prices and other events.

The showcase

The showcase, however, may be in Northlake, Ill., a 430,762 sq.-ft. energy-efficient building the company will move into in April 2008. It was built by Ascent to house multiple tenants, but Microsoft will lease the entire building to support data-center operations for Windows Live, Hotmail, and MSN Video.

While Microsoft will install its own green design inside the building, the structure itself has unique qualities.

"I think the real story with the building is the size and scale, the proximity to transmission-grade power, the dedicated onsite substation and the outside air-cooling efficiency. That is where the real sizzle is," says Phil Horstmann, founder and CEO of Ascent, which has been building and operating data centers since 1998.

The building sits on 12 acres and connects to the power grid at 138,000 volts, which is about eight times higher than typical connection voltage, Horstmann says. The connection provides a very efficient power supply and makes the building one of the most powerful data-center developments in the United States, he says. He would not reveal construction costs for the building.

For the inside of its data centers, Microsoft has come up with a set of design classes for energy efficiency and created standards around such things as server and rack configurations.

"It is really about how we take these designs and how they fit into the local area," says Mike Manos, senior director of data-center services for Microsoft. "Which design is going to give you the biggest impact, the most servers, the most efficient power with the most sustainability."

Up to old tricks?

Like all other service providers, Microsoft won't discuss specifics about its internal configurations and power-saving tricks, deeming those a competitive advantage that improves profits.

Those that have been on the inside, however, say Microsoft is doing cutting-edge work.

"I had an opportunity to tour their Bremerton [Wash.] facility and the raised floor system was fabulous for long-term flexibility, particularly in their industry," says Kath Williams, principal consultant of Kath Williams + Associates. Williams was president of the World Green Building Council from 2004 to 2007, and vice chair of the U.S. Green Building Council from 1996 to 2003. While she says she is not familiar with Microsoft's overall green plan, she adds, "Any step by any [company], particularly the biggies, any step is major. We are turning a big ship."

Microsoft's effort to influence that turn naturally extends to its software.

Vista's default settings for power management are far more aggressive than those in previous versions, and sleep mode happens much more quickly, Microsoft's Bernard says.

Power management extends to servers in Windows Server 2008, which will support a virtualization technology called Hyper-V that allows consolidation of servers to improve CPU use and provide real-time capacity management.

Bernard says such applications as Live Meeting and Roundtable can help reduce travel needs.