Those Bloom Energy fuel cells that eBay said it will use to power its new data center in Utah? They'll run on natural gas. Likewise most Bloom Boxes going in these days. But they can run on biogas – and eBay, like many of the companies turning to fuel cells these days, is paying a premium for its natural gas in order to enable biogas production.

Apple's fighting back against claims that its newest data-center is a coal-guzzling blight on the planet - but Greenpeace isn't convinced. In a report released yesterday, Greenpeace slated Apple's new facility in Maiden, North Carolina, claiming it would draw about 100 megawatts of electricity and that 90 percent of its power was generated by coal. Apple's disputing these figures. It says the data center will consume only 20 megawatts, and that eventually 60 percent of the power will be delivered by an on-site solar farm. But Greenpeace isn't giving up, pointing to the scale of Apple's investment in the plant and its physical size as signs that the company isn't telling the truth.