Bob Mobach, a consultant at systems integrator Logicalis Group, helped the NCTD redesign its data center. He says a key to realizing an ROI with alternative power is embracing virtualization. The agency's data center is about 80% virtualized, and that's a primary reason why the solar arrays are such a successful power source.
"Virtualization was critical for so many reasons," says Miller, noting that the new setup is "way more efficient," makes better use of hardware, gives the data center a smaller footprint and is easier to manage with fewer people. "My actual physical footprint went from not having any more slots in the racks available to having only half of the racks occupied, and yet we've increased our applications this year," she says.
Analysts laud efforts like the NCTD's but warn that solar power isn't right for every data center. "The level of efficiency you can get out of solar energy is dictated by the location of the data center," says Forrester Research analyst Doug Washburn. "If you are in an area where the sun shines more frequently, you can take advantage of a solar investment."
One reason why solar may not be the best data center power source is the fact that data centers use 10 to 100 times more energy per square foot than a typical office complex, Washburn says. Moreover, resiliency and uptime are so crucial to a data center's operation that "it's a critical risk, and maybe even foolhardy to think you could power the majority of your data center from solar," he adds.
Washburn agrees that virtualization is key to the success of a solar project. Increasing the number of hosts per machine, consolidating storage and decommissioning equipment that has been virtualized can make a data center more efficient even before an energy switch-over, he says.
Power From Jet Engines
Christopher Sedore, the CIO at Syracuse University, says the upstate New York school spent about $12 million to build a data center that uses natural-gas-fired microturbines from Capstone Turbine to generate power on-site.
Microturbines are essentially jet engines that run on natural gas and provide power to generators. The turbines produce about a half a megawatt of power for the university's data center and another 200 kilowatts for other uses, such as powering an adjacent building.
The turbines enable the university to have a co-generation setup, meaning they can help generate both heat and power for the data center or nearby buildings. The university can also sell any extra power the turbines generate back to the local power company.