Just one year after Greenpeace called out Apple for its use of fossil fuels in its "How Green Is Your Cloud" report – which graded Apple no higher than a "D" in four categories consisting of energy transparency, infrastructure siting, energy efficiency, and renewables and advocacy – Apple announced that its data centers are now powered by 100 percent renewable energy. In fact, renewables contribute to 75 percent of its entire corporate operations energy needs, according to its website.