Energy Options: Alternative Power Sources for Data Centers
Elizabeth Milard recently posted an interesting article on alternative power sources for data centers on Processor.com. Here are some of the highlights.
"With energy consumption on the rise—and expected to keep growing—data center managers are continually on the lookout for ways to increase efficiency and cut down on power and cooling costs. Although alternative energy strategies such as solar and wind aren’t widespread yet, the move toward green technology could boost adoption rates in the coming years.
“Basically, anything that can offset the use of commercial power and its associated costs is being looked at,” notes Kris Domich, principal consultant at Dimension Data. “The cost to get (to cleaner, greener centers) might be too high for most data centers right now, but it’s likely to come down as the interest keeps growing.”
New partnerships, such as the recent agreement between Lawrence Livermore National Laboratory signed with Siemens Energy to provide high-resolution atmospheric modeling capabilities, a strategy that can improve the efficiency of wind farm operations, offers great possibilities.
The laboratory’s modeling will allow for better weather forecasting, which is vital for boosting wind performance, according to Julie Lundquist, a Livermore scientist who heads the project. She notes that the methods they’ve developed for simulating turbulent properties of the lower atmosphere will result in a predictive advantage for wind energy farms.
Hydro power, fuel cells, biomass, and geothermal power sources are also being actively explored. Each has its challenges but also potential. For example, in some smaller-scale applications, fuel cells can be used to replace the traditional battery plant for long-runtime applications. The power density of fuel cell stacks, coupled with very low maintenance and potential tax incentives, have made this power source one worth watching.
Some medium-sized and larger data centers and colocation facilities have been exploring the use of alternative power. Emerson Network Power opened a new energy-efficient center last year in Missouri, using the state’s largest solar array. When the 35,000-square-foot center went live, it was 31% more efficient than traditional data centers, thanks to the solar technology, precision cooling products, and other efficiency strategies.
When Emerson first decided to build the center, it set out to achieve silver-level certification in LEED (Leadership in Energy and Environmental Design) but ended up garnering gold-level instead, according to Jack Pouchet, director of energy initiatives at Emerson.
“We also knew the 7,800-square-foot rooftop solar array would contribute a portion of the energy needed to run the data center,” he says. “We purposely oriented the building in such a way and put the array at an angle to the building structure so that we could capture the most amount of sun in the process.” The result, he notes, is that the solar array covers up to 15% of the data center’s load.
The solar array is anchored by a purpose-built super structure that’s on a permanent tilt, with no penetration of the roof over the data center. Pouchet says, “As we were laying this out, we also made certain that we could get to the back side of the panels to wire them.” He added that the building sits back far enough to minimize issues with trees, pollen and leaves, and the amount of rain and slope of the array also work to keep the modules clean.
For most data centers, using alternative power doesn’t mean making a clean break with the power company. Instead, this type of power is now being used to increase efficiency and lower consumption costs, and most likely, it will take some time for smaller data centers to implement technologies that harness solar, wind, biomass, and other strategies in a way that’s cost effective.
“Right now, the cost to get in is pretty high,” says Domich. “But most likely, it won’t be like that forever. As more data centers start putting systems in place, and demand increases, hopefully the costs will start coming down.”