A typical 10,000-square-foot data center consumes enough juice to turn on more than 8,000 60-watt lightbulbs. That amount of electricity is six to 10 times the power needed to operate a typical office building at peak demand, according to scientists at Lawrence Berkeley National Laboratory. Given that most data centers run 24/7, the companies that own them could end up paying millions of dollars this year just to keep their computers turned on.

And it’s getting more expensive. The price of oil ($60 a barrel in February) may fluctuate, but the cost of energy to run the data center probably will continue to increase, energy experts say. This is because global demand for energy is on the rise, fueled in part by: the proliferation of more powerful computers. According to Sun Microsystems engineers, a rack of servers installed in data centers just two years ago might have consumed 2 kilowatts and emitted 40 watts of heat per square foot. Newer, "high-density" racks, which cram more servers into the same amount of space, are expected to consume as much as 25 kilowatts and give off as much as 500 watts of heat per square foot by the end of the decade. The dire predictions keep coming. Most recently, a Google engineer warned in a research paper that if the performance per watt of today’s computers doesn’t improve, the electrical costs of running them could ultimately exceed their initial price tag.

"As the demand for computing grows, the cost of power is a larger and larger concern," says Dewitt Latimer, CTO at University of Notre Dame. Latimer is grappling with finding the space and adequate power to handle a growing demand for cheaper and ever-more powerful high-performance computer clusters at Notre Dame. The problem comes not just from the computers themselves; Latimer is worried that the air-conditioning needed to keep the machines cool will also eat away at his budget.

Like Latimer, every CIO who is responsible for a data center—even those who outsource data center management to a hosting company—faces this conundrum: how to keep up with ever-increasing performance requirements while taming runaway power consumption. The problem is most pressing for companies on either coast and in large cities in between, where space is at a premium and companies compensate by putting more servers into their existing buildings. And there is no simple solution. Business demand for more applications results in companies adding more servers. According to market research company IDC (a sister company to CIO’s publisher), server sales are growing by 10 percent to 15 percent annually.