Wind Turbines: A Serious Threat to Birds?

Wind turbines are becoming a popular, sustainable and renewable energy source for generating electricity. But how is it affecting the bird population?

Wind power is a critical source of renewable, carbon-free energy for replacing and reducing emissions from fossil fuels such as coal, oil, and natural gas, which causes climate change.

Whilst wind energy benefits birds globally by reducing climate change, wind power installations can injure birds by direct collisions with turbines and other structures, such as power cables. Wind farms can potentially degrade or destroy habitat, cause disruption and relocation, and disrupt critical ecological links. Placing wind projects in the way of migratory routes adds to the problem, particularly for larger turbine blades that may reach up into the typical flight zone of night-migrating birds.

Turbine collisions kill an estimated 140,000 to 500,000 birds per year, and in the U.S. state of Pennsylvania, wind turbines kill over 10,000 bats per year according to the Wall Street Journal.

Of course, birds die for a variety of reasons such as: glass-walled office buildings, utility towers, traffic collisions and carnivorous animals (including domestic cats) BUT wind turbines kill much more birds per year than all of the reasons above.

So what exactly is the problem here? Larger birds of prey are drawn to the lattice work seen on older models of wind turbines as it offers them an ideal perch. To put into perspective, wind turbine blades, while appearing to whirl at a moderate, almost relaxed speed, actually move quite quickly. The outer ends of some turbine blades may reach speeds of 179 mph, easily severing an eagle’s wing.

As the number of wounded and dead birds grows, numerous solutions to the awful tragedies of birds and bats at wind farms have been offered. One possibility is the newer turbine designs, which are without the lattice frames and are instead replaced with vertical-axis rotors. These have the potential to lessen the fatal impact of wind turbines on bird populations globally and hopefully these newer models will be rolled out soon.

The American Bird Conservancy’s Bird-Smart Wind Energy program is a great resource for promoting the best practices for wind energy development. They share that another solution is to locate wind turbines in locations with lower bird populations.

Dr Megan Murgatroyd and her colleagues, from Hawkwatch International created a predictive model that advises developers where Verreaux’s eagles are most likely to fly in a specific region, allowing companies to situate their wind turbines away from certain areas. In an interview with the BBC she stated: “If the model had been used, up to 79% of [those deaths] could have been avoided.”

Hopefully in the near future, we are able to see these newer models of wind turbines being used and already in the UK bat and bird evaluations are now required as part of the planning application procedure for wind farms.

Looking for more information? Check out the BBC’s great breakdown.