Meanwhile, HP and IBM have attempted to address power and space problems through their blade designs, but as mentioned, heat dissipation can become an issue with high-density racks. One solution is to reduce the total number of servers in deployment; even when servers are running efficient chips, analysts say too often the machines are underutilized.

“People for a long time have adopted a one-application-per-server model,” IDC’s Bailey says. What results are datacenters with hundreds of machines, each of which runs at a small fraction of its capacity. The problem is that a server that’s only 10 percent utilized draws almost as many watts as one that’s running at 80 percent capacity.

Bailey and other IT advisers say companies can reap big savings by consolidating a handful of small jobs onto a single box through virtualization technologies. On the extreme end of this trend, IBM also advocates the use of mainframes running virtualization software, which it says allows many of its customers to replace dozens of juice-thirsty servers with a single machine (albeit an expensive one).

Non-IT offenders

Replacing old machines with more energy-efficient gear and consolidating servers are great initial steps, but real power savings in the datacenter can’t be accomplished until managers tackle a snarl of inefficiencies that don’t fit as neatly into the traditional purview of the IT department.

That’s because for every watt that a server in the typical datacenter consumes, another 1 to 1.5 watts are burned up by nonserver gear, says Jonathan Koomey, staff scientist at Lawrence Berkeley National Laboratory. To solve the problem, IT managers must address long-standing shortcomings in air-conditioning systems, power equipment, and other gear that has not traditionally been a responsibility of their department.

“There’s really nobody on the IT side that’s seeing an electricity bill and saying, ‘Gee, I’m responsible for making that meter spin,’ ” says Richard Hodges, principal of GreenIT, a consultancy that advises clients on how to reduce IT power costs.

Bill Clifford, CEO of Aperture Technologies, a supplier of software that helps manage datacenters, agrees. His advice to IT managers: “Go find out who your facilities liaison is and become really good friends. A smart CIO today is going to want to have those types of people on their team to anticipate needs and not simply react to problems.”

The biggest problem with most cooling systems is that datacenters typically have way more than is needed, says Neil Rasmussen, CTO with American Power Conversion, which provides products and services for powering datacenters. He says many datacenters use gear that’s rated for three times as many servers as they’re actually serving. “A lot of people think, ‘I’ll invest in power and cooling for the future,’ ” he says. “In the meantime, you have this big 8,000-horsepower engine and it’s burning fuel.”

Overbuilding made more sense in past decades because installation of air-conditioning systems could require the removal of entire building walls. Now the gear is more modular, which allows designers to add units more gradually, as they are needed.