Efficient power distribution systems are vital as well. More than 10% of a power supply can dissipate while it travels from the edge of a building to its destined target inside the data center, according to Kosik.

"It's not sexy stuff, but it makes a big difference," Kosik says. "Right now, there's huge momentum in the industry to push energy efficiency, but from a more pragmatic standpoint."

In many cases, retrofitting isn't feasible from a financial perspective, and it's better to build a data center from scratch. In addition to helping HP plan two new U.S.-based data centers as part of the 85-to-6 consolidation, EYP has provided consulting services to many of the world's top financial institutions, major Internet and software companies, and high-performance computing centers.

A 1-megawatt data center's energy needs can reach US$2 million a year, Kosik says, adding that some of the bigger Internet companies need data centers of 20 to 30 megawatts.

Many data centers are burdened with out-of-date servers, power supplies and building designs, notes Mark Linesch, vice president of marketing for an HP software division that focuses on managing and automating use of servers and storage. (Compare )