Black rotor blades reduce bird deaths

winds turbines

A study carried out over several years shows that the simple act of painting one of the three blades of wind turbines black would be enough to protect birds from the risk of collision.

We currently depend on fossil fuels and nuclear fission reactors to produce enough energy. The former are pollutants and the latter are the source of much radioactive waste. This is why for several years now, “green” solutions have been proposed, such as wind farms.

Wind power though is not perfect. The elements that make up this type of structure (rare earths, carbon fibers) are in fact not recyclable and are also pollutants. Furthermore, they pose a significant threat to biodiversity, and in particular to birds.

First of all, it should be noted that before any wind turbine installation, it is now mandatory to carry out an impact study so that the sites chosen for these farms present the lowest possible risk for wildlife. However, zero risk does not exist. And ultimately, the more parks there are, the greater the risk of collisions.

However, few cost-effective deterrents or mitigation measures have so far been developed to reduce these risks of death. In a study published in Ecology and Evolution, Norwegian researchers tested a simple and affordable approach: painting one of the blades black.

The researchers carried out their experiments at the Smøla wind power plant in Norway. The site was built in two phases: 20 turbines of 2.1 MW were installed in September 2002, then 48 other turbines of 2.3 MW joined them in August 2005. As part of this work, only four painted turbines and four neighboring untreated turbines were used.

The team also used trained dogs to search for bird carcasses within a hundred meters of the turbines “at regular intervals”.

More than 9,500 searches were carried out between 2006 and 2016, leading to the discovery of 464 carcasses. The researchers then pointed out “an average reduction of 71.9% in the annual mortality rate near painted turbines compared to control turbines”. Overall, and despite the limited number of turbines included in the study, these results remain sufficient to seriously consider this approach as an effective way to protect birds.

In addition to the number of lives saved, this little trick would also reduce the cost of repairing wind turbines, but also the loss in terms of energy (a stopped turbine cannot produce electricity).