Apple has been at the receiving end of increasing criticism from environmental campaigners Greenpeace recently. This has resulted in considerable attention being paid to the Cupertino-based firm's energy-intensive datacenters, which environmentalists say are run by power sourced from coal-fired power plants.

In a rather interesting twist however, Apple fired back today with some quite astonishing facts that suggest the company is actually at the forefront of clean and renewable energy. Apple claims its datacenters in Austin, Tx., Sacramento, Ca., Munich, Germany and County Cork in Ireland are all powered by 100% renewable energy. Even Apple's Cupertino headquarters is powered by 50% renewable energy.

They also explained that regulatory approval has been granted for the firm to use renewable energy at its Newark, Ca. datacenter, which should be running by February 2013. But that's not all they had to say.

Apple is currently building two 100-acre solar farms in Maiden, North Carolina which once finished towards the end of this year and in use will cover 60% of the datacenter's power requirements, with the remainder provided using other renewable energy methods sourced locally and regionally. In the iconic US retailer's own words, it will be "the most environmentally sound data center ever built."

"Apple's datacenter in Maiden, North Carolina, will draw about 20 megawatts of power at full capacity. We'll be producing an unprecedented 60 percent of this power onsite. To do that, we're building what will be the nation's largest private solar arrays and the largest non-utility fuel cell installation operating anywhere in the country. That's a scale of onsite renewable energy production that no other company has matched," said Apple.

If that wasn't enough to make Greenpeace eat their words, the firm's datacenter currently under construction in Princeville, Oregon  "will be every bit as environmentally responsible" as their Maiden data center.