After coming under attack by pro-environment groups, Apple has tried hard to burnish its green image. But its latest laptops could ruin its reputation among the carbon-conscious. Apple has touted the innovation of its new "unibody" laser-manufacturing process, which carves the MacBook's body out of a block of aluminum. "The process uses a huge amount of energy to machine each case and then to recycle the material removed," an expert on computer supply chains tells Valleywag. "It's a much less efficient and there's a huge amount of waste than any other process to make the housings." The charge could be electrifying, if proven true.Apple has devoted an entire page to the MacBook's environmental merits . The company has taken considerable steps to lower the amount of energy used by the MacBook's display, hard drive, and processor. But Apple is vague about the energy consumed by making the MacBook's laser-carved unibody, and recycling the wasted aluminum. The Container Recycling Institute estimates that 3 percent of the world's electricity goes towards manufacturing aluminum — and China, where most of Apple's manufacturing is done, gets most of its electricity from dirty coal plants.