Wind Turbines' Big Threat: Wind

Advocates of green energy will be happy to know that the Energy Department wants the nation to get 20% of electricity from the wind by 2030. A good chunk of that power is slated to come from offshore turbines, notes New Scientist, and therein lies a problem. Researchers at Carnegie Mellon studied four proposed wind farm sites and predicted that hurricanes would probably take down about half of the turbines over time. Given that the farms can cost $175 million apiece, that's no small thing.

"We want these risks to be known now before we start putting these wind turbines offshore," says one of the researchers. "We don't want any backlash when the first one goes down and it costs a lot to replace." (More wind power stories.)