Data center managers' interest in power has changed as energy costs rise. Large data centers, such as Apple's and Google's, are turning to renewable energy generation to offset the cost. Along the way, these early adopters are dealing with varied challenges.
Businesses spend almost as much on power and cooling as they do on data center servers, according to International Data Corp., an analyst firm based in Framingham, Mass. Rather than simply buy traditional oil- or coal-based electricity, large data centers are being designed to run on renewable energy: solar, wind, water -- and even biogas and seawater.
"We are in an early stage, but there has been a growing interest in using renewables in the data center," said Eric Woods, a senior analyst at Pike Research Inc., based in Boulder, Colo.
Businesses are embracing green energy for various reasons. "In some cases, renewable energy is aligned with a company's own sustainability strategies or culture," said John Pflueger, board member of The Green Grid from Dell Inc. Green initiatives can enhance a business's image as a good corporate citizen.
The renewable movement also meshes with corporate marketing messages. "IT vendors have been touting the environmental benefits of cloud computing, but they are only true if clean energy is pumped into the data center," noted Woods at Pike Research.
Hyperscale tech companies Apple Inc., Google Inc. and Microsoft Corp. are validating renewable energy data center designs, with the expectation that customers will eventually follow in their tracks.
The Apple data center in Maiden, N.C., relies entirely on renewable power as part of a multifaceted renewable energy project. The company built a 100-acre, 20-megawatt plant that will produce 42 megawatts of energy annually. Two solar arrays provide more than 60% of that power. In addition, Apple is partnering with NC GreenPower -- an independent, nonprofit organization created by the North Carolina Utilities Commission -- to increase renewable energy production throughout the state. Apple and NC GreenPower are using a local landfill (located just three miles from the Maiden data center) to generate electricity from waste materials' methane gas.
Google, which has committed over $1 billion to renewable energy projects such as large-scale wind systems and rooftop solar panels, uses renewable energy to power more than 30% of its operations. The company worked with NextEra Energy Resources to funnel 48 megawatts of wind-generated electricity to its Mayes County, Okla., data center. The Google data center in Hamina, Finland, uses seawater from the Bay of Finland to cool its servers, storage systems and network devices -- another green initiative that saves rather than generates energy.
Microsoft is experimenting with powering a data center via biogas from a wastewater treatment facility. This 200 kW Microsoft data center project requires collaboration with the city of Cheyenne, Wyo.; the University of Wyoming and Fuel Cell Energy Inc.
Incremental benefits, fundamental problems
Renewables are not a perfect fit for the data center. Google notes that locations with the best renewable power potential are not generally the same places where a data center would ideally operate. Data centers are usually stationed in large, metropolitan areas with abundant electricity and telecommunications lines. Renewable energy generation often occurs in remote areas; moving the energy from these locations onto the electric grid has been an ongoing challenge for utilities.
Solar and wind power rely on energy from nature, so their output is often quite scattershot. If clouds move in or the wind dies down, little to no energy is produced. Contrary to this intermittent power production, large data centers are constant energy consumers, operating 24 hours a day, seven days a week. The limitations of capricious weather mean that renewables are often a supplemental -- not primary -- energy source.
Emerson Network Power incorporated a 7,800-square-foot rooftop solar array on its global data center at the company headquarters in St. Louis. "We knew we wanted to integrate some form of renewable energy into our data center," said Jack Pouchet, director of energy initiatives at Emerson Network Power, but the photovoltaic solar panels only meet about 16% of the facility's electricity needs.
Renewable energy also typically relies on direct current, whereas data center equipment works on alternating current electricity. Converters drive up costs and reduce the renewables' benefits.
"We are starting to see pieces of data center equipment that are architected specifically around renewables," said The Green Grid's Pflueger. "For example, fuel cells for on-site generation of electricity." Expect -- at least in the early stages of adoption -- to pay more for these systems and do more integration work than on traditional solutions.
Renewable energy power sources hold a great deal of potential, but they also come with the hard edges usually found with emerging technology. Understand that change is coming but proceed cautiously, understanding the true costs and output of renewable installations.
Paul Korzeniowski is a freelance writer who specializes in data center issues. He is based in Sudbury, Mass., and can be reached at firstname.lastname@example.org.