Why Elastollan® TPU
- High mechanical performance with controlled flexibility
- Very good low-temperature behavior
- Strong resistance to UV and environmental exposure
- Injection molding for industrial scale and consistent quality
Performance Polymers
FeatherEdge®
When Wind Turbines Learn to Whisper
FeatherEdge® - When Wind Turbines Learn To Whisper
How an owl, a smart material, and a bold partnership help wind turbines to get quieter
On quiet nights the wind can sound loud. As blades cut through the air, they leave a turbulent signature – especially at the trailing edge – that travels far and can limit when and where turbines run. The surprising inspiration for a better way?
Owls: masters of silent flight. That silent flight sparked an idea that’s now reshaping wind energy. Their feather fringes inspired a new take on blade serrations that don’t fight the air – it works with it.
The idea came from Biome Renewables, a design‑driven cleantech company translating biological strategies into scalable engineering.
Green energy yes, but silent please
Society increasingly welcomes renewable energy and wind power plays a central role in achieving climate and decarbonization goals. But while green energy is widely supported, the turbines that generate it are not always as quiet as the communities around them would like.
As turbines grow larger and more efficient, they also produce more low-frequency noise—the deep, far-traveling sound created when turbulent air mixes at the blade’s trailing edge. This type of noise is especially sensitive for residents living near wind farms and can become a crucial factor in public acceptance, permitting, and nighttime operations.
The challenge is clear:
How can turbines continue delivering clean energy without increasing acoustic impact?
The idea – Bioinspired Insight
Sometimes, the best engineering insights don’t come from wind tunnels or simulations, they come from nature. And in this case, nature had already solved the very problem turbines struggle with. It came from the silent flight of owls.
Owls use serrated fringes on their feathers to break up turbulent flow and soften the transition where noise is born. Biome tried to mimic the feathers of the owl to see how they can translate it into solutions for the serrations of wind turbines.
When we started the project, we didn’t know really what material we had to go for. …existing products of serrations in wind turbines, .., they are very stiff.
But the trick to mimic the feather is that the part, the serration, must be stiff and flexible at the same time.
Translating this principle to wind turbines led to refined, flexible serration for the blade’s trailing edge that helps smooth airflow and target the low-frequency band that carries the farthest.
The Material Behind the Magic: TPU
To function outdoors for ~20 years, the part must be flexible and stiff at the same time, resilient against UV, temperature extremes, moisture, and mechanical loads.
Early thermoset trials proved the concept; moving to injection molded thermoplastic Polyurethane (TPU) enabled scalability and precise, repeatable performance.
The Solution: FeatherEdge® Serrations
FeatherEdge® is a customized, retrofitready system that places flexible serrations at key locations along the blade span. Unlike rigid designs, these segments are engineered to move just enough to manage turbulent mixing—reducing noise at the source while preserving aerodynamic efficiency.
Highlights
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Flexible geometry designed for the trailing edge
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Configurable placement for different turbine models
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Retrofitfriendly installation with minimal downtime
Proven Results and Operational impact
Windtunnel validation and early field testing indicates ~3–6 dB reduction (standard serrations ~2-3 dB), with a notable impact in low-frequency ranges. On large turbine trials, reductions around ~3.7 dB have been observed. A 3 dB drop halves acoustic energy is small on paper but meaningful at night for nearby residents.
And lowering acoustic emission, means that operators can reduce curtailment at night, potentially extending operating hours and increasing annual energy production without major hardware changes.
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