On a windswept archipelago off Norway's central coast, a quiet experiment at the Smøla wind farm offers a small but telling answer to an old tension between clean energy and the lives of wild birds. Painting a single blade on some turbines black appeared to cut bird deaths by more than seventy percent, a result that rests on years of patient counting rather than a hurried snapshot. Yet the same idea faltered when tried in the Netherlands, reminding us that a remedy born in one landscape does not travel unchanged to another. As researchers now test other colors at sea, the story reads less as a
Why One Black Turbine Blade Can Cut Bird Deaths, and Why the Fix Doesn't Work Everywhere
A cheap-sounding fix that works well in one place and poorly in another
On a windswept archipelago off Norway's central coast, a quiet experiment at the Smøla wind farm offers a small but telling answer to an old tension between clean energy and the lives of wild birds. Painting a single blade on some turbines black appeared to cut bird deaths by more than seventy percent, a result that rests on years of patient counting rather than a hurried snapshot. Yet the same idea faltered when tried in the Netherlands, reminding us that a remedy born in one landscape does not travel unchanged to another. As researchers now test other colors at sea, the story reads less as a finished solution than as a careful inquiry into how birds see the world.
At the Smøla wind power plant, on an archipelago off Norway's central coast, researchers spent more than a decade counting dead birds beneath the turbines. In August 2013, one blade on each of a small group of the plant's 68 turbines was painted black, and the counting went on. The design set four ordinary turbines beside four neighbors with a single black blade, searching for carcasses within 100 meters of each. Combining 7.5 years of earlier counts with 3.5 years after painting gave the team a long record rather than a fleeting glimpse.
The 2020 findings, published in Ecology and Evolution, showed a drop of more than 70 percent in bird deaths, most striking for the white-tailed sea eagle. The researchers were careful, calling the evidence anecdotal and warning it might not hold for other populations. The proposed reason lies in how birds perceive motion. Fast-spinning blades of one color can blur into a single circle, while a black blade breaks that pattern and makes the moving parts easier to tell apart.
The method has limits. Some species may lack the visual sharpness to notice the difference, and painting working turbines demands lifts and crews willing to work high above the ground. Dutch experiments failed to reproduce the Norwegian results, suggesting that local species and population size shape the outcome.
At sea, the Dutch consortium Ecowende is now testing red instead, fitting seven large Vestas turbines with one red blade each. Meanwhile, a Scottish study at the Aberdeen offshore farm followed 2,007 flight paths and found no confirmed collisions, with birds usually keeping 100 to 200 meters away. The emerging picture is of a promising fix that works in one place and not another, and whether it is needed everywhere remains an open question.
At the Smøla wind power plant, on an archipelago off the coast of Central Norway, researchers spent more than a decade counting dead birds around the turbines. The plant has 68 turbines in total. In August 2013, one blade on each of a small group of them was painted black, and the counting continued.
The design was a comparison. Researchers from the Norwegian Institute for Nature Research set four ordinary turbines beside four neighboring ones with a single black blade. They regularly searched for bird carcasses within 100 meters of the structures. The dataset joined 7.5 years of baseline counts from before any painting with 3.5 years afterward, which gave them a long before-and-after record rather than a short snapshot.
The result, published in 2020 in the journal Ecology and Evolution, was a drop of more than 70% in the number of bird deaths. The effect was especially pronounced for the white-tailed sea eagle, a somewhat rare bird in the region. The researchers cautioned that the data is anecdotal and may not hold for other bird populations. Still, it counted as independent, real-world confirmation of a laboratory experiment that had found similar results in 2003.
The proposed explanation concerns how birds process what they see. Animation designers use the term motion smearing: when something moves faster than the eye can follow, the brain infers a single continuous motion. Rotating blades of one uniform color can read as one giant circle, which makes the threat hard to notice. A single black blade breaks up that pattern, making the moving blades easier to tell apart.
The fix has limits. As Audubon reported, these are preliminary findings that will not translate equally to all species, particularly those without the visual acuity to pick up the difference. There is also real effort involved. Painting turbines that are in operation requires lifts and specialist crews able to work at height.
Experiments in the Netherlands did not produce the same positive results. The apparent reason is that the technique depends heavily on the local bird species and the size of the population, so a result from Norway cannot simply be exported.
Most of the land-based trials so far have stuck with black. At sea, a new trial is trying another color. The Dutch consortium Ecowende is fitting seven Vestas V236-15.0 MW turbines with one red blade each, measuring 115.5 meters. Red was chosen after weighing options against criteria including durability and heat management, besides being easier to discern from a distance.
Seabirds may also need less help than expected. A study by Vattenfall and Spoor at the Aberdeen offshore wind farm tracked 2,007 flight paths over 19 months and found no confirmed collisions. Birds typically kept 100 to 200 meters away from the turbines.
The picture that emerges is of a cheap-sounding fix that works well in one place and poorly in another. Whether red blades at sea prove useful, and whether they are needed at all given the Aberdeen findings, are the questions the offshore trial and later studies will have to answer.
Citações Notáveis
The findings are preliminary and won't translate to all bird species equally, especially those lacking the visual acuity to notice the difference.— Audubon, as reported in the story
Quer a matéria completa?
Leia o original em TechRadar ↗