To support the high densities introduced by virtualization and other technologies such as blade servers, cooling must be brought close to the rack and server, Simonelli says. As it stands, cooling is already the biggest energy hog in the data center, with power wasted because of over-sized AC systems and temperatures set too low, he says.

While every data center has different needs, Simonelli says enterprises can learn something from the co-location data center in Las Vegas, a 407,000 square-foot building that relies heavily on APC equipment, such as NetShelter SX racks, thousands of rack-mounted power distribution units and UPS power supplies.

While the site can support 60 megawatts, it’s being built out in 20-megawatt chunks. “That means they can maximize the energy consumption, the efficiency of the data center as they scale. They’re not powering the 60-megawatt site right away,” Simonelli says.

One of the biggest mistakes is to over-size power capacity, in anticipation of future growth that may never come. Companies have to plan for where they think they will be a few years from now, but build out in smaller increments, he says.

“You have to have the floor space, and you have to have the capability of getting power from the utility,” Simonelli says. “But if you’re going to build out a one- or a five-megawatt data center, and you know that your first year of deployment is only going to be 100 kilowatts, get the space and make sure you have power from the utility for five megawatts but just build it out in 250 or 500 kilowatt chunks.”