Renewable energy
Monitoring and surveys

Black blade to reduce bird collisions

Waardenburg Ecology and Altenburg & Wymenga are jointly investigating whether painting the blade of a wind turbine black helps to reduce the number of bird collisions. This research is an initiative of the province of Groningen and RWE in collaboration with other governments, conservation organisations and private parties from the wind sector.

Motion blur

One possible method to prevent birds colliding with a wind turbine is to increase the visibility of the rotating rotor blades. Experiments by Hodos (2003) showed that motion blur can be reduced by giving one of the blades a different colour.
This principle was recently studied by May et al. (2020) on the island of Smøla in Norway. That study revealed that painting one of the blades black reduced the number of collisions of white-tailed eagles by 70% (May et al., 2020).

Research design the Netherlands

Research in the Netherlands in now investigating whether this approach is also effective for other species, and in a different landscape. This research is being carried out at 14 existing RWE wind turbines in the Eemshaven wind farm, a location with high levels of bird migration. After an initial year of victim searches (baseline measurement), one blade on each of seven wind turbines was painted black. Victim searches will be carried out for two years to compare numbers of collisions at painted and unpainted turbines.

Result and effectiveness

This study will determine the difference in mortality between the painted turbines and the (unpainted) control turbines. We will compare this with any difference between the same two groups of wind turbines during the baseline measurement. This will provide data into the effectiveness of a black blade as a measure to reduce mortality. The black blade research started in 2021 and the results are expected at the end of 2024. If the black blade works, this could potentially be an attractive alternative to shutting down wind turbines to reduce bird mortality.
Read the press release that TNO has issued