A ” contrast paint ” that could speed up the authorization of new wind farms and allow the installation of turbines in places that were previously considered too problematic, according to the scientists.
Norwegian scientists have found that painting one of the three wind turbine blades black reduces bird deaths by 72%.
If this “contrast paint” were applied to new onshore and offshore wind farms, it could reduce problems, speed up authorization processes and allow wind farms to be built in locations previously considered too problematic, they write in a scientific paper.
The study by researchers from the Norwegian Institute for Nature Research examined data on bird kills collected between 2006 and the end of 2016 at Statkraft’s 152.4 MW Smøla wind farm on the island of the same name. , rich in birds, located off the western coast of Norway.
Four turbines from the Smøla project had a single blade painted black in August 2013, resulting in bird deaths for seven and a half years before painting and three and a half years after.
Trained sniffer dogs were used to find the birds and feathers on the wind farm turbines, and dead birds found by wind farm staff and bystanders were also recorded.
The data showed that there was “ an average 71.9% reduction in the annual mortality rate after painting the turbines relative to the control turbines [ie unpainted] ”.
The authors of the study, which was published in the journal Ecology and Evolution, noted that the number of deaths fluctuated “considerably” from year to year, “underscoring the need for a long-term study” to support their conclusions.
Why does a black shovel reduce bird collisions?
In the article, the scientists explain why a single black blade helps birds perceive the rotor as an obstacle.
Relative to humans, birds have a narrow binocular [eg, using both eyes to focus on an object] frontal field of view and probably use their monocular [using each eye independently] and high resolution lateral [ie. , having eyes on opposite sides of their heads] to detect predators and prey.
Within a so-called open airspace, birds may therefore not always perceive obstacles ahead, thus increasing the risk of collision. To reduce collisions, the provision of ‘passive’ visual cues can improve the visibility of the rotor blades, allowing birds to take evasive action in good time.
It is believed that painting a sheet of black creates patterns that the bird perceives as a moving object, ” since the frontal vision of the birds can be more adjusted to the direction of movement “.
The Norwegian scientists concluded: “ We recommend either replicating this study, preferably with more treated turbines, or applying the measure in new locations and monitoring collision fatalities to see if similar results are obtained elsewhere, to determine to what extent the effect is generalizable . “
More information: wiley.com