Scientists take inspiration from palm trees to make hurricane-resistant wind turbines

Scientists have looked to wind-resistant palm trees to build offshore wind turbines that can withstand Atlantic hurricanes.

A team at CU Boulder were looking for ways to strengthen wind turbines, which now reach 490 ft tall and power around 4000 homes in the US but are at risk from increasingly powerful hurricanes.

Traditionally thick wind turbine blades have to be stiff to avoid being blown into the tower, meaning they can be quite expensive due to their size.

After studying palm trees, researchers found that downward facing blades, were less likely to break as they faced away from the tower and could be lighter, more flexible and cheaper to make.

‘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,’ said Mandar Phadnis, lead author on the new study and a graduate student in electrical, computer and energy engineering.

The team collaborated with various organisations to develop the Segmented Ultralight Morphing Rotor (SUMR) turbine, a two-bladed, downward rotor which performed consistently and efficiently during periods of peak wind.

They have also improved the wind turbines controllers to improve productivity during extremely low or fast wind speeds which affect the amount of energy they can create.

These feedback controllers measure how the system is performing and then adjust to perform more efficiently, a system the scientists are trying to maximise during peak wind events.

‘Our work attempts to predict the likelihood or the probability of peak wind gusts occurring, and then tries to mitigate the speed peaks by acting before they happen,’ said Phadnis.

In tests during strong wind across Highway 93 in Colorado, researchers found that controllers with peak generator speeds couldn’t keep the turbine running.

It’s thought the improve controllers, lighter materials and strategic turbine configurations could help offshore turbines outpace competitors, as more cost-effective and energy efficient energy sources.

In related news, fossil fuels are still dominating the energy market according to a report which said the world missed a prime opportunity for a green recovery following COVID-19 lockdowns.

Photo by Insung Yoon