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, chilers "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% 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."