The US tech giant's plants in Maiden, North Carolina, and Prineville, Oregon were recently named in a highly-critical report by Greenpeace, claiming that Apple powers its data centers by 55% "dirty power" - coal and nuclear.
Last month, activists from the charity targeted Apple's Regent Street store in London, covering the windows of the outlet with leaflets on energy consumption.
After Apple refuted the claims in Greenpeace's report, the company is now making a more concerted effort to show the environmental credentials of its data centres.
On a new environmental section of its website, Apple said that it plans to power the Maiden data centre entirely with renewable energy sources before the end of 2012.
The company, led by chief executive Tim Cook, also said that all three US data centres - Maiden, Prineville, Oregon and Newark, California - would soon be "coal-free", claiming that this is an industry first for a company of Apple's size.
An Apple spokeswoman said that on-site generation at Maiden of clean, renewable energy will provide 60% of the power needed to run the sprawling data centre.
This will be made possible by the establishment of a massive solar farm using land in Maiden recently purchased by Apple, with the remaining power coming from renewable energy generated near the site.
"Prineville, Oregon is in the planning stages. Any power we need from the grid will be 100% renewable and locally generated. Newark will be converted to 100% clean energy by February 2013," the spokeswoman added.
The maker of iPhone and iPads said yesterday that it was purchasing equipment from SunPower Corp and startup Bloom Energy to establish two solar array installations close to the Maiden data centre.
Once up and running, it is thought that the solar farm will be able to supply 84 million kWh of energy annually using high-efficiency solar cells and an advanced solar tracking system.
> Apple co-founder Steve Wozniak to advise on Sony's Steve Jobs biopic
In an interview with Reuters, Apple chief financial officer Peter Oppenheimer said that he was "not aware of any other company producing energy on-site at this scale".
"The plan... 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 centre in Maiden, which will help us meet this goal," said Oppenheimer.
He added: "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.
"We haven't finalised our plans for on-site generation, but any power we need to run our centre in Prineville that we get from the grid will be 100% renewable and locally generated sources."