Aside from cogeneration, natural gas turbines can serve another purpose, he says. Some metropolitan areas limit the amount of electrical power a facility can use. "It may make sense to put turbines on a roof to provide additional electricity," he explains.
Fuel cells at First National Bank of Omaha
One of the most promising new technologies for powering data centers is the hydrogen fuel cell. Hydrogen fuel cells don't produce any harmful emissions, so companies such as Verizon, Whole Foods and Google have opted to use them as an alternative power source for office or retail space.
Few organizations use fuel cells to power data centers because the cost would be prohibitive. But the First National Bank of Omaha built a fuel-cell-powered 200,000-square-foot data center in 1999 because such systems tend to be reliable. The data center is about the size of a football field; it's surrounded by a dry moat, like a castle, and is powered entirely by four 200-kilowatt fuel cell generators. If the data center does lose fuel cell power, which is extremely unlikely, a rotary UPS system can carry a short-term load.
"With the fuel cells, we have seven 9s of reliability, or about two or three seconds of downtime per year," says Brenda Dooley, president of First National Buildings, a bank subsidiary that handles corporate real estate and facilities management. "We came from a system with backup batteries. When we'd lose power, the batteries just wouldn't be there. We did this for reliability."
Dooley explained that the credit card processing that's done at the data center requires high reliability: Just one hour of downtime could result in a loss of as much as a $6 million.
The bank knew that using fuel cells would be expensive. AC energy costs in Nebraska are only about 5 cents per kilowatt-hour, whereas electricity from fuel cells costs about 12 cents per kilowatt-hour. It would have cost $2.2 million to build a data center that used AC power; the decision to use fuel cells raised the price tag to $3.4 million. Dooley says the investment was worth it and the ROI is excellent because the bank doesn't experience lost transactions.
Of course, not every enterprise is willing to pay a higher price for such great reliability.
"Fuel cell technology is not there in terms of volume and scale to support larger data centers," says Nemertes analyst Ritter. "But down the road, it is very interesting potentially as a backup power source because some data centers have regulations on what they can put in for [backup AC power] generators."
Ritter says one thing to consider if you're thinking about using an alternative power source is whether your local electric utility already provides reliable service. He said First National Bank of Omaha likely wanted to ensure that it wouldn't have to deal with power failures and was therefore willing to pay much more for a reliable source of electricity. Indeed, Dooley confirms that the bank has in the past endured power failures once or twice a year. Those outages would typically last only a few minutes, but they would end up costing thousands of dollars because of lost transactions, she says.
Alternative power has a bright future for data centers. Ritter says there may be no other option in the coming years if traditional energy prices soar higher. Whether it's solar power, gas turbines, fuel cells or some emerging option -- such as harnessing the power of ocean waves -- it's clear that new power sources will play a role in the data centers of the future.
John Brandon is a former IT manager at a Fortune 100 company who now writes about technology. He's written more than 2,500 articles in the past 10 years.