Wind turbines could be retrofitted with technology inspired by the Andean condor, one of the world’s largest birds, to significantly boost their energy output, according to a new study.
Adding “bio-inspired winglets” to turbines can raise their power output by an average of 10%, according to a team from the University of Alberta’s Department of Mechanical Engineering in Canada.
The team have taken inspiration from the Andean condor, one of the largest birds on Earth, weighing up to 15 kilograms with a wingspan of over three metres. Andean condors are soaring birds which can travel 240km in a day without flapping their wings.
Inspired by the shape of their wings, Biome Renewable, a Canadian industrial design firm that employs biomimicry to enhance renewables production, launched “Project Condor” and designed a “novel” blade tip for turbines.
These can be added post-production addition to turbines, with the winglet coming in at just over five metres.
The researchers, who used Biome's winglet design as a reference in the paper, published in the journal Energy, said the boost in power production is due to the “aerodynamic changes introduced by the winglets, not just an increase in the rotor’s swept area.”
This is because the winglets modify the “vortex structures at the blade tips, reducing the rotational tendencies of the flow near the tip.”
“Tip vortices” are created when turbine blades move through the air, which swirls against the direction of travel for the blade – an effect known as “downwash.”
“Most modern-day airplanes, from business jets to military planes, use winglets to minimise the effects of tip vortices,” said the researchers, reducing drag on those machines.
Using computer modelling, the researchers found that adding the condor-inspired winglets to a sample 10MW turbine “drastically affected the vortex structures at the tip, reducing the rotational tendencies of the flow at the vicinity of the tip.”
The researchers said the results of their study “suggest that this bio-inspired design can increase the power output of the wind turbines while also facilitating the recovery of velocity lost due to the power extraction in the wake.”
The team said they are now conducting further research into the design using “more advanced turbulence models.”
