Autonomous Detection Systems (ADS): Mere Illusion or a True Tool to Reduce Bird Collision Risks?

Following the court ruling on the Bernagues wind farm, Sens of Life provides a factual review of the conditions surrounding the collision with a Golden Eagle in 2023.

On April 9, 2025, a court ordered the shutdown of the Bernagues wind farm for a period of one year, following the death of a Golden Eagle that collided with a turbine which had received a stop command. Sens of Life aims to explain how such a collision could occur.

As part of an educational approach, Sens of Life wishes to explain the mechanisms of the Autonomous Detection System (ADS) offered to operators—its features, limitations, and proven effectiveness.

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• Features of the Detection System:
An ADS consists of a network of cameras that detect the presence of birds and send the signal to an AI, which calculates the risk level and issues a stop command to the turbine if necessary. This system can be complemented by a deterrence device.
Given the mechanical constraints of the rotor, an immediate stop is not possible. The stop command results in feathering the turbine blades, allowing it to decelerate to a residual speed of less than 3 rotations per minute (rpm)—a speed generally considered non-lethal.
In this case, the turbine was operating at 15 rpm when it received a stop command from our ADS. The blades were therefore feathered and rotating at 1.9 rpm at the time of the fatal collision with the Golden Eagle.

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• Limitations of Any Detection System (ADS):
It is important to clarify that detection systems are considered a means of reducing mortality, not of complete avoidance.
In 2024, across the 59 wind farms equipped with our PROBIRD® system, our ADS issued an average of 12.2 stops per day per turbine. On most of these sites, no bird collisions were recorded. We observed at least one mortality on 7 of the 59 farms.
All these data are documented in an annual performance report provided to our clients, who are responsible for forwarding it to the regional environmental authorities (DREAL).
No technological system can claim a 100% risk reduction when it comes to wildlife. Nevertheless, the wind energy sector continues to work on continuously improving these systems.

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• The Effectiveness of ADS:
Since 2017, we have been equipping wind farms with the PROBIRD® system.
Thanks to our experience, we are currently rolling out version 1.9, which further strengthens bird protection efforts.

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Press contact:
Christophe ALBARRAN, Director of Biodiversity and Public Relations
Email: [email protected]
Phone: +33 7 66 04 19 22

Link: Press release