Atlantic hurricanes pose risks to renewable energy wind turbines, and researchers at the University of Colorado-Boulder are developing more resilient models. Lucy Pao, the Palmer endowed chair in the Department of Electrical, Computer and Energy Engineering, says, “We are very much bio-inspired by palm trees, which can survive these hurricane conditions.” Traditional upwind turbine blades face into the wind, so the blades must be stiff, which requires more material and increases cost. Blades on downwind rotors face away from the wind, with less chance of hitting the tower when the winds pick up, so they can be lighter and more flexible, requiring less material. Downwind blades can also bend, instead of break, like palm trees do.

Over the last six years, Pao’s team, in conjunction with collaborators at the University of Virginia, the University of Texas at Dallas, the Colorado School of Mines and the National Renewable Energy Laboratory, have collaborated to develop the Segmented Ultralight Morphing Rotor turbine, a two-bladed, downwind rotor, to test the concept in action. The researchers found that their turbine performed consistently and efficiently during periods of peak wind gusts. Mandar Phadnis, lead author of a study in Proceedings of the 2022 American Control Conference, says, “The blades are manufactured to be lightweight and very flexible, so they can align with the wind loads.”