The amount of electricity used by giant server farms in the Pacific Northwest that power the Internet continues to grow and will eventually approach the consumption rate of the region’s aluminum smelters 30 years ago.

According to a recent analysis by the Northwest Power and Conservation Council, demand from these data centers by 2030 could be about two-thirds of the power consumption of the Pacific Northwest aluminum industry during its heyday in the 1980s.

Facebook, Google, Apple, Microsoft and other companies have built data centers in the region.

Facebook estimates about 526 million people will log in every day this year through a desktop computer or a mobile device — a 41 percent increase over 2011 usage. Facebook users also upload more than 300 million photos a day.

While growth in demand by server farms in the region is proceeding as anticipated, the council reported, it should be improved.

“The amount of data these centers handle is growing at an explosive rate, making it imperative that data centers continue to improve their energy efficiency to keep power demand from exploding as well,” the council reported.

Custom data centers house digital electronic equipment for Internet site hosting, electronic storage and transfer, credit card and financial transaction processing, telecommunications, and other activities that support the growing electronic information-based economy, the council reported.

“Our region has several advantages for data centers — low-cost power and a mild climate, which are important for powering and cooling computer equipment, and state tax incentives to locate here,” council chairwoman Joan Dukes said. “Data centers potentially could use as much power as aluminum smelters, and as the region’s electricity planning agency, we are watching the growth of this industry carefully.”

By the 1980s, the 10 aluminum smelters in the Pacific Northwest and its 11,000 workers produced about 40 percent of the primary aluminum in the U.S. and 6-7 percent of the world’s supply. The region’s smelters consumed about 3,150 megawatts, enough power to light up three cities the size of Seattle. The Columbia Falls Aluminum Co. smelter, one of three smelters still intact today, consumed about 350 megawatts of power at full capacity.

The council’s 2010 revision of its Northwest Power Plan estimated regional demand by data centers at about 355 megawatts in 2012 — enough power for about 106,000 Northwest homes. About half of that load would be for server farms like those operated by Facebook and Google.

Factors contributing to the growing electricity demand by server farms include increasing use of mobile devices such as smart phones and tablet computers, increasing consumer demand for photos and video, increasing use of remote “cloud” data storage, and legal requirements for long-term storage of financial information including electronic records, such as e-mail.

The council predicted demand could increase by about 7 percent per year over the 20-year horizon of their power plan. Improved energy efficiency, however, could cut demand growth to about 3 percent per year, reaching about 1,400 average megawatts in 2029.

But if projected efficiency improvements in data center operations are not realized, or if data centers expand in the region beyond current known plans, their power demand could increase to nearly 2,500 megawatts by 2030.