Bats go splat

Wind power is one of the most frequently cited sources of alternative energy, an environmental win-win whose only drawback is its cost. But if anything worries us about a renewable, emission-free power source, it might just be the gigantic metal blades at the end of every wind turbine. (As we’ve seen, they can get a little ugly “Too much of a good thing?”)

Thankfully, as ground-bound humans, we aren’t very likely to find themselves several stories up about to be sucked into tonnes of rapidly spinning metal. Unfortunately for our fine feathered friends, on the other hand, they just might be.

But despite the often-voiced concern over birds flying to their deaths, there’s been barely a squeak over the fate of bats, another winged animal that’s liable to take the odd detour through a windmill’s path. And as a group of University of Calgary researchers has discovered, these flying mammals may be at a greater risk than their avian counterparts.

Rather than running directly into the blades, bats are susceptible to sudden drops in pressure created by the windmill blades, which can cause them to succumb to a condition known as “barotrauma.” In the case of windmills, air pressure is raised and lowered rapidly as the air is sucked into the blades and, then, in the blades’ wake.

It’s worth noting that The Canadian Wind Energy Association makes particular note of the issue on their website (272 KB PDF), albeit without any particular mention of the issue of barotrauma. The point their information package makes is an important one to bear in mind: namely that any man-made structure, particularly buildings and windows, can be responsible for the death of flying wildlife.

Just the same, knowing about the potential hazards of existing wind turbine designs could go a long way to reducing the inevitable environmental impact of a power source that otherwise offers a marked improvement on the consequences of electrical generation.