Scientists develop new turbines that bend in strong winds like palm trees

Scientists are developing hurricane-resilient wind turbines inspired by palm trees with blades that bend instead of break in the face of strong winds.

With increasing sizes of hurricanes to meet the growing demands of renewable energy, turbines, especially those along the paths of powerful Atlantic hurricanes, pose a risk to themselves and to the future of wind energy, said scientists.

While upwind turbines that face the incoming wind need to be stiff, blades on downwind rotors that face away from the wind can be lighter and more flexible, scientists, including those from the University of Colorado (CU) at Boulder in the US, said.

In the new study, presented on 10 June at the Proceedings of the 2022 American Control Conference, researchers described a new turbine with a two-bladed, downwind rotor to test the performance of this lightweight concept in action.

The SUMR (Segmented Ultralight Morphing Rotor) turbine, described in a yet-to-be peer-reviewed study posted as a preprint in engrXiv, was found to perform “consistently and efficiently” during periods of peak wind gusts, scientists said.

“The blades are manufactured to be lightweight and very flexible, so they can align with the wind loads. That way, we can reduce the cost of the blades and bring down the cost of energy,” Mandar Phadnis, lead author of the study, said in a statement.

One of the main challenges in wind energy production is dealing with not enough or too much wind at one time.

When wind speeds are too low, turbines can’t produce a useful amount of energy. During harsh winds that push the limits of a turbine’s capacity, it may cause them to shut down to avoid a system overload.

In the new innovation, scientists have made changes to the controller, a part of the turbine that determines when to be more or less aggressive in power production.

“We like to think of the controller as essentially the brain of the system,” said Lucy Pao, senior author on the study from CU Boulder.

Scientists used the controller to predict the likelihood or the probability of peak wind gusts occurring, to try and mitigate peaks in wind speed by “acting before they happen.”

They believed the combination of improved controllers, lighter and resilient materials, and strategic turbine configurations could allow for improved giant offshore turbines.

Such combined features can lead to cost-effective and energy efficient turbines, allowing for one big turbine instead of many smaller ones, researchers said.

With hurricane activity projected to increase due to human-driven climate change, scientists said such turbines capable of withstanding severe weather can be implemented to capture faster wind speeds higher off the ground.

“Wind turbine blades are typically designed to last at least 20 years, and we want our novel concept blades to achieve similarly long lifetimes,” Dr Pao said.