The American Bird Conservancy estimates that between 700,000 and more than a million birds die each year due to collisions with wind turbines. Overall, these numbers are likely lower than incidents involving cats, buildings and cars, which are attributed to many more bird deaths. But it’s also a nuanced situation because rare birds have been affected, such as the thousands of golden eagles killed by wind turbines in the Altamont Wind Resource Area. Encouraged by such developments, many have called for action to find ways to reduce these numbers, if only to preserve endangered species.
The good news is that a lot of related research is already underway. For example, Norwegian researchers painted wind turbine blades black so that they contrast more with the surroundings, reducing collisions. Additionally, eagles continued to die at Wyoming wind farms until researchers installed automated cameras, also equipped with AI monitoring, to shut down the wind turbines when the birds flew too close. Europe is currently experimenting with a remarkably similar approach using a collision avoidance system called SKARV. Like the Wyoming eagle setup, SKARV uses cameras to detect approaching birds, then uses AI to predict their flight paths. The system then adjusts the pitch and speed of the turbine blades to reduce the risk of collision.
The flight paths of incoming birds are first recognized using ground-based radar. If they continue to approach the facility, another turbine-mounted camera will provide the updated details to the AI, informing of the slowdown or shutdown. This precise system can help minimize downtime, optimize energy production, while also benefiting the birds.
Why do birds collide with wind turbines?
Researchers believe that birds collide with the massive structures because the moving or rotating blades appear blurry, so that when they are several meters in front of them, the birds can barely perceive them. As the birds get closer, the blur of the spinning blades maintains a visual effect called motion smear. To make matters worse, many birds don’t look straight ahead when flying: instead, they look down, searching for prey or mates, or watch laterally for threats.
The black paint used by many avoidance systems essentially makes wind turbines more visible to birds, rather than just appearing as a large blob or motion blur. But more sophisticated systems like SKARV actually slow the blades, allowing birds to see the object better while giving them more time to fly through the rotor area without collision.
SKARV is currently in the knowledge acquisition phase, which means that researchers and the development team are still learning more about the technique and its impact. The project is expected to last from 2024 to 2027. We will soon know if it had a major impact and if it helped overall. Meanwhile, another unique alternative, currently being developed elsewhere, is the possibility of new bladeless wind turbines, which could be a real game-changer.
