Like many well-traveled Web destinations these days, eBay consumes tremendous amounts of energy to power its data centers. The EPA studied data centers’ energy use in 2006 and found that “The energy used by the nation’s servers and data centers...[was] about 61 billion kilowatt-hours (kWh) in 2006 (1.5 percent of total U.S. electricity consumption) for a total electricity cost of about $4.5 billion.” And it’s not hard to imagine that energy use has only grown since then, the recession notwithstanding. Other big technology companies like Google have at least addressed the issue of green data centers, and it’s nice to see that eBay has come on board. They recently opened a new data center in Phoenix, which was developed with help from The Green Grid, which utilizes a metric it calls the Power Usage Effectiveness (PUE) to “enable data center operators to quickly estimate the energy efficiency of their data centers, compare the results against other data centers, and determine if any energy efficiency improvements need to be made.” Says GreenBiz:
When planning its Phoenix data center, eBay stated it wanted a facility with a PUE of 1.2 and used that goal to guide its decisions. (Lower numbers indicate higher effectiveness.) The company said that the data center had a site average PUE of 1.35 during one week in January, with a 1.26 PUE at its best. Partial PUEs around 1.04 have also been recorded. ... The data center is also using its environment to receive free, year-round cooling in the form of a hot-water cooling system that uses cooling-tower water to chill containers and racks in the center. While computers use only 57 percent of the power in the average U.S. data center, the air conditioning and other equipment gobbling the rest, computers use at least 78 percent -- and up to 95 percent -- of the power in eBay's Phoenix facility.
The new data center was also designed to be scalable and accommodate up to five new generations of technology. One question, though: Phoenix? Really? Not, say, Minnesota, where it would be decidedly easier to cool the servers? Actually: “Phoenix lies in an arid desert, with summer temperatures peaking at 49°C, yet has an estimated 6,000 hours of free-air cooling available per year; tower water can be delivered at 31°C all year without using chillers.” Ah. Also, too: Facebook's new data center.