Image via Earthfirst
Wind turbines are an essential to our prospects of building a clean energy economy. Unfortunately, there's a lot of evidence out there that the turbines kill bats in alarming numbers--more than they do birds. And not in the gruesome manner you'd think--no high speed collisions with the blades--but in another gruesome way altogether. The sudden drop in air pressure around the turbines causes severe injuries to the bats' lungs, an affliction called barotruama. Thankfully, scientists have come up with a way to reduce bat deaths around turbines by at least 60% without sacrificing any serious power generation from the turbines. And the solution seems overwhelming logical to me. Essentially, it's this: stop the blades from turning when it's not windy, because that's when bats are most likely to take flight. I know, major revelation, you say--how many scientists did it take to come up with that? Well, the matter was a little more complicated than it might appear now--for example, it was puzzling that the most bats were killed while there were low winds, as opposed to higher winds when the turbines were turning faster, and potentially more dangerous.
Science Daily reports that a new study has revealed that "slowing turbine blades to near motionless in low-wind periods significantly reduces bat mortality" by some 60% in preliminary studies.
"Biologically, this makes sense as bats are more likely to fly when wind speeds are relatively low. When it's really windy, which is when the turbines are reaping the most energy, bats don't like to fly. There is a potential for biology and economics to mesh nicely," says U of C biology professor Robert Barclay.So, the scientists have now reduced the amount that the rotors on wind turbines turn in slow wind speeds in 38 locations in North America, and bat deaths are down. They note that it's easy to manipulate the operating speeds of most wind turbines already out there.
This is encouraging news. As wind power operations expand in North America, they're conflicting with concerns from conservationists--they were even banned in parts of North Carolina. And bat and bird deaths have been a longstanding worry with wind turbines--perhaps this solution, once improved, will allow wind turbines and bats to coexist without leading to any more ruptured lungs.