Scientists discover how to avoid bat genocide from wind power

Wind turbines popping up in various parts of the globe are a big part of the overall renewable energy movement, but at the same time they’re a deadly problem for nearby bat populations. Bats typically travel at altitudes where wind turbine blades spin and the immediate difference in air pressure is fatal for them.

Solving the problem is deceptively simple, and requires slowing down the turbine blades to a near standstill during low wind periods. Bats would then be able to dodge the blades like they do any other obstacle using sonar and wouldn’t suffer from air pressure differences. Making that single change could amount to a reduction of bat killings by about 60% according to a preliminary study, but what about the energy lost because of those slowdowns?

It would be a relatively small loss, which makes sense because the blades would only slow down during low wind periods anyway. In an early experiment adjusting 15 turbines to the lower rotor speeds, TransAlta saw a loss of $3,000 - $4,000. It’s good to see a company attempting to mitigate its impact on local ecology despite some losses, especially when it’s at the forefront of the green movement building wind farms.

Most of the killings occur in bat populations that migrate, like hoary and silver-haired bats. Until recently environmentalists have focused on protecting bird populations but bats are dying from wind turbines in greater numbers now. Partially that’s due to adjustments made to protect birds.

Bats flying near the spinning wind turbine blades suffer from barotrauma, which puts an extreme strain on the bat’s lungs as air pressure changes.

TransAlta has applied the speed adjustments to 38 turbines in the study area and plans to standardize new installations with the same changes. More research is necessary to confirm the cost of the adjustments, and the effectiveness of preserving bat populations. But, it’s a great start.