A new study has emerged claiming that painting wind turbines reduces the number of bird deaths by 70% at the conclusion of a nine-year study.
Researchers in Norway say that they’ve come up with an ingenious way of reducing the estimated 328,000 bird deaths each year from wind turbines by painting a single blade black.
They’ve published the findings of a nine-year study in the journal Ecology and Evolution, which says that “overall, there was an average 71.9% reduction in the annual fatality rate after painting at the painted turbines relative to the control turbines.”
Researchers conducted the study on the Norweigan islands of Smola, where there is an 18-kilometer wind-farm with 68 turbines; one of the largest in Norway.
Co-author of the study, Dr Roel May of the Norweigan Institute for Nature Research has told The BBC that the “collision of birds, especially raptors, is one of the main environmental concerns related to wind energy development… in Norway, 6-9 white-tailed eagles are killed annually within the Smola wind-power plant; this caused opposition and conflict,” Dr May said.
May continued to explain that “one of the mitigation measures we tested was painting one of the three rotor blades black… the expectation is that this design reduces so-called motion smear, making the blades more visible to birds.”
The results of the study showed that there was indeed a dramatic drop in the number of birds killed by the wind turbines.
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“Seasonally, fatality rates across years were strongly reduced at the painted turbines after treatment during spring and autumn, but increased during summer… when grouping data by season instead of years, painting reduced seasonal fatality rates by 70.9%,” the authors wrote.
The researchers suggested that the painted rotor blades may have helped birds form a cognitive map of their surroundings and “also have made birds more aware (or vigilant) of those turbine locations, leading to anticipatory evasion.”
In their conclusion, the researchers said that “applying contrast painting to rotor blades resulted in a significantly reduced annual fatality rate (70%) for a range of birds at the Smola wind-power plant,” adding that they “recommend to either replicate this study, preferably with more treated turbines, or to implement the measure at new sites and monitor collision fatalities to very whether similar results are obtained.”
Dr May echoed this in his interview with the BBC, stating that “although we found a significant drop in bird collision rates, its efficacy may well be site and species-specific. At the moment, there exists interest to carry out tests in the Netherlands and in South America.”
“If done prior to construction, it will be a very cost-effective measure that may help reduce unnecessary conflicts. What hasn’t been tested yet, is whether other rotor blade patterns – eg red blade tips as used to warn aviation – might be equally effective,” May concluded.
A spokesperson for wind turbine manufacturer Siemens Gamesa has told the BBC that “we don’t take part in the ongoing running of a wind farm, so we’re not familiar with instances of bird strikes,” however the spokesperson did confirm that “we could manufacture to a specification laid down by the developers.”
Martin Harper, director of conservation at the RSPB has said that construction of wind farms should “take pace in harmony with nature.”
“Wind turbines are the right technology when we find the right places for them,” he said, “so studies like this are valuable and build on our understanding of what additional mitigation could be used once we identify locations suitable for wind farms.”
“As the report acknowledges, this studied a single site and more work needed to be done, so we would be interested in seeing more research in this area,” Mr Harper said.
U.S. President Trump once labelled wind turbines, “bird graveyards,” although pundits have said there are other, more significant reasons for his critique of renewable energy.