Facebook has begun building a data center in Lulea, Sweden, where it will benefit from cheap electricity and year-round free air cooling, the company announced Thursday.
The data center will be Facebook's first in Europe, and its third worldwide. The company expects the first server building to enter service next year, with two others to follow by 2014. Each building will cover an area of 28,000 square meters.
Lulea is on the edge of the Arctic Circle, and has a mean annual temperature of around 1 C, with average summer highs of around 20 C, allowing Facebook to save money by cooling its data center with fresh air rather than air conditioning.
Using free air cooling will help Facebook increase a key measure of data center efficiency, its PUE (power usage effectiveness). PUE is calculated as the total power consumption of the data center, including cooling and lighting systems, divided by the power consumption of IT systems. The less power wasted on ancillary functions such as cooling and lighting, the more energy-efficient the data center becomes.
Average PUEs for major data centers typically lie between 1.6 and 1.99, according to a survey published by the Uptime Institute in May. Capgemini said last December that its Merlin data center in the U.K. had a factory-tested PUE of 1.1.
Facebook has not yet announced its target PUE for the Lulea data center.
The servers there will run primarily on hydroelectric power from the nearby Lule river, Facebook said. Lulea has the cheapest electricity in Europe, according to the city's business development agency.
Facebook has developed its own power-efficient servers and power supplies for data centers, publishing technical specifications and CAD files for them through the Open Compute Project. That organization will hold a summit in New York later Thursday.
Peter Sayer covers open source software, European intellectual property legislation and general technology breaking news for IDG News Service. Send comments and news tips to Peter at firstname.lastname@example.org.