Apple Inc. plans to power its main U.S. data centre entirely with renewable energy by the end of this year, taking steps to address long-standing environmental concerns about the rapid expansion of high-consuming computer server farms.
The maker of the iPhone and iPad said on Thursday it was buying equipment from SunPower Corp and startup Bloom Energy to build two solar array installations in and around Maiden, North Carolina, near its core data centre.
Once up, the solar farm will supply 84 million kilowatt-hours of energy annually.
The sites will employ high-efficiency solar cells and an advanced solar tracking system.
Later in 2012, Apple also intends to build a third, smaller, bio-gas fuel-cell plant.
The two solar farms will cover one square kilometre, among the largest in the industry, Apple CFO Peter Oppenheimer told Reuters. Apple plans on using coal-free electricity in all three of its data centers, with the Maiden facility coal-free by the end of 2012.
"I'm not aware of any other company producing energy onsite at this scale," Mr. Oppenheimer said in a telephone interview. "The plan we are releasing today includes two solar farms and together they will be twice as big as we previously announced, thanks to the purchase of some land very near to the data center in Maiden, which will help us meet this goal."
Concerns about the ever-expanding power consumption of computer data centers have mounted in recent years, as technology giants build enormous facilities housing servers to cater to an explosion in Internet traffic, multimedia use and enterprise services hosting, via cloud computing.
"Our next facility will be in Prineville, Oregon. This is still in the planning stages and we have already identified plenty of renewable sources nearby," Mr. Oppenheimer said.
"We haven't finalized our plans for on-site generation, but any power we need to run our center in Prineville that we get from the grid will be 100 percent renewable and locally generated sources," the Apple CFO said.
Shares in SunPower leaped more than 9 per cent to trade around $5.55 on Thursday afternoon.
SunPower, now majority-owned by France's Total SA, makes the most efficient solar panels in the world, according to industy analysts. Prices for solar panels -- particularly at large-scale solar plants like the one Apple envisions -- have been dropping rapidly, narrowing the gap with the cost of fossil fuel power.
"SunPower will take a bite out of Apple's environmental impact with our highest efficiency solar at their North Carolina data center, the nation's largest privately-owned solar array," SunPower CEO Tom Werner said via email.
Greenpeace, which has also targeted Amazon.com and Microsoft with clean energy campaigns, hailed the move.
"Apple's announcement today is a great sign that Apple is taking seriously the hundreds of thousands of its customers who have asked for an iCloud powered by clean energy, not dirty coal," Greenpeace International Senior IT Analyst Gary Cook said in a statement.