Slaughtering Wildlife with Green Energy

Here's a good illustration of the law of unintended consequences:

Bats are something of a one-species stimulus program for farmers, every year gobbling up millions of bugs that could ruin a harvest. But the same biology that allows the winged creatures to sweep the night sky for fine dining also has made them susceptible to one of Pennsylvania's fastest-growing energy tools.

The 420 wind turbines now in use across Pennsylvania killed more than 10,000 bats last year -- mostly in the late summer months, according to the state Game Commission. That's an average of 25 bats per turbine per year, and the Nature Conservancy predicts as many as 2,900 turbines will be set up across the state by 2030.

Bats are nature's pesticide, consuming as many as 500 insects in one hour, or nearly 3,000 insects in one night, said Miguel Saviroff, the agricultural financial manager at the Penn State Cooperative Extension in Somerset County.

"A colony of just 100 little brown bats may consume a quarter of a million mosquitoes and other small insects in a night," he said. "That benefits neighbors and reduces the insect problem with crops."

If one turbine kills 25 bats in a year, that means one turbine accounted for about 17 million uneaten bugs in 2010.

Bats save farmers a lot of money: About $74 per acre, according to an April report in Science magazine that calculated the economic value of bats on a county-by-county basis.

In Allegheny County, bats save farmers an estimated $642,986 in a year. That's nothing compared with more agricultural counties in the region such as Somerset ($6.7 million saved), Washington ($5.5 million) or Westmoreland ($6.1 million).

Lancaster County? You owe bats $22 million.

It's not just bats that are dying around wind turbines. An estimated 1,680 birds were killed by turbines last year, according to the state Game Commission report.

The disparity in mortality stems from biology. Birds typically crash into the blade and die from blunt force trauma, while bats suffer from a condition called barotrauma. It's the bat equivalent of the "bends" that scuba divers can suffer if they surface too quickly.

The rapid drop in air pressure around the blades causes the bats' lungs to burst, and they collapse with no ostensible lacerations or scars on the body.

I'll bet the bats and birds are happy to know that green energy sources are so much more earth-friendly than those awful fossil fuels.