Google, with an estimated 900,000 servers, dedicates considerable attention to data center efficiency and other best practices, like, where and when possible, using evaporative cooling to minimize how often energy-hogging "chillers" run (When in use, chillers "can consume many times more power than the rest of the cooling system combined"). Evaporative cooling still requires power -- but much less. And Google's new facility in Hamina, Finland, "utilizes sea water to provide chiller-less cooling." (See Google's video.) According to the company, "Google-designed data centers use about half the energy of a typical data center."
[ See also: Visit a Google Data Center ... if you dare! ]
Renewable, carbon-neutral power
In addition to looking for affordability, many data center planners are looking at power sources that don't consume fuel, or otherwise have a low carbon footprint.
For example, Verne Global is cranking up a "carbon-neutral data center" in Iceland -- currently scheduled to go live November 2011 -- powered entirely by a combination of hydro-electric sources and geothermal sources, according to Lisa Rhodes, VP Marketing and Sales, Verne Global. (About 80 percent of the power will come from hydro-electric.)
Power in Iceland is also abundant, Rhodes points out: "The current power grid in Iceland offers approximately 2900 Megawatts (MW) of power capacity and the population of Iceland is roughly 320,000 people. Their utilization of the total available power is thought to be in the range of 300MWatts. Aluminum smelters are currently the most power-intensive industry in Iceland, leaving more than sufficient capacity for the data center industry."
Iceland's year-around low ambient temperatures permit free cooling, says Rhodes. "Chiller plants are not required, resulting in a significant reduction in power cost. If a wholesale client should decide they want cooling at the server, there is a natural cold-water aquifer on the campus that can be used to accommodate their needs."
Depending on where the customer is, the trade-off for locating data centers based on power, cooling or other factors, can, of course, be incrementally more network latency -- the delay caused by signals travelling through one or several thousands of miles of fiber, plus, possibly, another network device or two. For example, one-way transit from the data center to London or Europe adds 18 milliseconds, to the United States, about 40 milliseconds.
It's not just the heat, it's the humidity
"Dry places" aren't necessarily in cool locations. i/o Data Centers' Phoenix facility, which according to the company is one of the world's largest data centers, is located, as the facility's name suggests, in Phoenix, Arizona.
"One of the benefits of the desert is it's very dry," says Anthony Wanger, i/o President. "It's easier to remove heat in a dry environment, which makes Arizona an ideal location."
According to the company, the Phoenix data center employs a number of techniques and technologies to reduce energy consumption and improve energy efficiency.