When is a wind turbine like an owl?
Wind turbine blade noise reduced by biomimicry.
Nature has often had hundreds of millions of years to evolve solutions to engineering design problems. When the principles of those solutions are borrowed to design better stuff, it’s called biomimicry. Here is a biomimicry example: how the detail of owl wing feathers, which allows them to fly silently,1 is being applied to wind turbine blade trailing edges.
Wind turbines produce noise both from their generators and from their blades moving through the air. Large, utility-scale turbines produce sounds in range of 35-45 decibels (dB) when measured about 300 metres away. Some of that noise comes from blade trailing edge turbulence.2 Generally, the bigger the wind turbine, the noisier and more intrusive they are, limiting where they can be located, and sometimes when they can operate.
A Canadian company, Biome Renewables, has developed feather-like appendages that can be attached to the trailing edges of existing (or new) turbine blades to reduce the noise they generate by at least 3.4 dB. That may not sound like much, but keep in mind that the decibel scale for sound is logarithmic, so 3.4 dB less corresponds to roughly a 50% reduction in perceived sound.3
The technology also reduces sound more at low frequencies, which travel farther, so the noise reduction may be perceived as being even more effective than a simple decibel measurement would suggest.
This is a relatively simple change that should allow wider use of renewable wind power.
Sweet Lightning has no affiliation with any products or manufacturers mentioned in this article.
Reading
- Experiment! How Does An Owl Fly So Silently? | Super Powered Owls | BBC, 2016. https://www.youtube.com/watch?v=d_FEaFgJyfA.
- Deshmukh, Shubham, Sourodeep Bhattacharya, Anuj Jain, and Akshoy Ranjan Paul. “Wind Turbine Noise and Its Mitigation Techniques: A Review.” Energy Procedia 160 (February 2019): 633–40. https://doi.org/10.1016/j.egypro.2019.02.215.
- Peters, Adele. “These Nearly Silent Wind Turbines Have Owl-Inspired ‘Feathers.’” Fast Company, January 8, 2025. https://www.fastcompany.com/91256113/these-nearly-silent-wind-turbines-have-owl-inspired-feathers.