Researchers Develop Hurricane Resistant Wind Turbines Based On Palm Tree Structure

The increasing size of wind turbines’ tower and blades for greater energy harnessing has caused a problem of its own kind; especially on the coasts of the USA. The hurricanes (cyclones) pose risks to the wind turbines structures and to the future of wind energy. Now a team of researchers from Colorado University in Boulder have taken inspiration from nature and created wind turbines technology just like palm trees to withstand the challenges of hurricanes. “We are very much bio-inspired by palm trees, which can survive these hurricane conditions,” said Lucy Pao, Palmer Endowed Chair in the Department of Electrical, Computer and Energy Engineering speaking to an environment blog.

Traditional turbines can be damaged by the incoming winds. Hence use of thick and massive blades drives up their cost. But turbine blades on downwind rotors have less risk of damage when the winds pick up. They are lighter and flexible, which requires less material and therefore less money to make. These downwind blades can also then bend instead of break in the face of strong winds—much like palm trees. With most turbines almost 120 metres tall and higher now, the need for resilience in the face of rough weather is even more important. Nw, with even floating wind turbines making an appearance, managing extreme weather events is even more important.

Collaborators at the University of Virginia, the University of Texas at Dallas, the Colorado School of Mines, and the National Renewable Energy Laboratory and Lucy Pao’s team partnered to develop the SUMR (Segmented Ultralight Morphing Rotor) turbine, a two-bladed, downwind rotor to test the performance of this lightweight concept in action. At the American Control Conference, the CU researchers presented results from a new study of four years of real-world data from testing their 53.38 kilowatt demonstrator (SUMR-D) at the National Renewable Energy Laboratory’s (NREL) Flatirons Campus, just south of Boulder, Colorado.

They found that their turbine performed consistently and efficiently during periods of peak wind gusts—a satisfactory result. The invention is claimed to have come at the right time when the rising global temperatures are also likely causing hurricanes to intensify.

The hidden brain of a turbine

The fast winds, inconsistent winds can shut down the turbine systems leading to less energy generated and less efficient production. Pao has improved the controller in her technology that determines when to be more or less aggressive in power production. He calls it as the brain of the system.

Typically, onshore and offshore wind farms can endure upto category 3 storms because to built-in technologies that lock and feather the blades, twisting them so they don’t catch the wind and rotate when wind speeds surpass 55 miles per hour. The turbine resumes normal operation once the storm has passed.

The yaw controller makes sure the turbine is facing the correct direction, the blade pitch controller determines the direction of the blades (dependent on the wind speeds), and the generator torque controller decides how much power to pull off the turbine and onto the grid. Moreover, its software maximizes the system’s ability to keep running during peak wind events.

Scaling up world wind energy

Researchers claim that the control algorithms that they have developed could also be equally applicable to traditional three-bladed, upwind turbines, which still dominate both land and offshore markets.

“The advantage of the downwind configuration, however, really comes about when you get to extreme scale turbines, and those are primarily for offshore,” said Pao. The researchers are already addressing the great heights: With their collaborators, they have designed and modeled (but not experimentally tested) large-scale, offshore 25 MW and 50 MW SUMR (downwind) turbines.

Ultimately, she believes a combination of improved controllers, lighter and resilient materials, and strategic turbine configurations could allow for giant offshore turbines to outpace the competition. She says that her technology could also withstand the more severe weather sure to come.