The extreme winds generated by climate change-driven monster storms are already pushing against the limits of some wind turbines, it turns out.
The research question is how resilient wind farms are to extreme wind events, which research has shown are becoming more intense as global warming barrels on. The study focuses on Class III turbines, a type designed for relatively mild conditions.
This is what they found. Climate change has barely gotten started, and already over 40 percent of existing and planned offshore turbine farms in Europe and Asia are exposed to wind beyond the speeds they were designed to tolerate, warn Yanan Zhao and Zhenzhong Zeng of the Southern University of Science and Technology, Shenzhen with colleagues in a paper published Tuesday with colleagues in Nature Communications.
Storm surge coming
Global warming is not in doubt, and we are causing it – that is not in doubt either. How matters will proceed is unclear because Earth has entered uncharted territory. We know that rising carbon dioxide and methane levels translate into hotter temperatures; we just aren’t sure how high the temperatures will climb, or when. Meanwhile, one upshot has been intensifying storms.
Hurricane Melissa that hit Jamaica in October with wind speeds of up to 185 miles per hour (295 kilometers per hour was a storm on steroids. Global warming ramped up Melissa’s wind speed by 7 percent, a separate study found, adding that the Melissa “event” was “unlikely” without climate change. Yeah.
“Climate change is amplifying the intensity of extreme strong winds,” Zhao and the team begin, starting with rare and welcome clarity. Their paper relates to a specific turbine type, Class III, which are designed for relatively lower wind speeds and are widely used in Europe, Asia and the United States. They naturally didn’t ask every wind farm in Europe, Asia and the Americas what turbine type they use, but Class III is in wide use.
Class I and II models can cope with stronger winds based on the design thresholds set by the International Electrotechnical Commission (the international standards organization for electrical technologies), and there are even more robust ones too. Why wouldn’t everybody and their dog use the strongest model to begin with, and be done with worries about resilience?
Cost, of course. Being designed for environments with mild, average and extreme winds (roughly 7.5 meters per second mean wind load and a 37.5 meters per second extreme wind load), Zhao confirms that Class III is cheaper than sturdier models. Because their structural strength requirements are lower, they can be built with simpler reinforcement designs, significantly reducing manufacturing and installation costs, he explains.
What actually happens to wind turbines when the wind exceeds their design limits?
Basically – first they try to cope by adjusting blade angles. If that doesn’t solve the problem, they shut down and wait for the storm to pass.
“Wind turbines survive storms primarily through their design and automated control systems,” Zhao explains. “As wind speeds approach or exceed the cut-out threshold, the turbine’s pitch control system adjusts the blade angles to reduce rotational speed and aerodynamic loads. The yaw control mechanism also keeps the nacelle facing the wind direction to minimize structural stress,” he elaborates.
And if that doesn’t suffice? Does the turbine seize up and collapse? Not usually. “If the maximum design load is exceeded, turbines generally do not seize or fail immediately. Instead, safety systems automatically shut down operations. However, in extreme cases such as a super typhoon, if wind speeds far surpass the design limit, structural damage can occur including blade fracture, tower bending, or even full collapse,” he says.
Indeed, Super-Typhoon Yagi in 2024 caused at least six turbines to collapse in Hainan, China. It reached a wind speed of 150 miles per hour (245 kilometers per hour) or 74.5 meters per second.
Typhoons and turbines
A collapsed turbine is a nightmare. Typically collapse means severe structural failure of the main components, Zhao explains. There is the cost of dismantling, transporting, and rebuilding the giant offshore machine, which can reach hundreds of millions of yuan (there are 14 cents to the yuan today – in short, it’s a terrible waste). Then there is the cost of building a new one, possibly a stronger and more expensive one to boot.
So what have we learned so far? Class III is designed to max out at 37.5 meters per second. Yagi was more than twice as powerful and Melissa reached maximum wind speeds of about 80 meters per second.
Storms called once in a lifetime, or once in a century, or never in living memory are now happening almost every day somewhere. The team assesses that more than half of the existing wind farms are located in regions where extreme wind speeds are projected to increase.
What is to be done? Does the technology even exist that can survive the mega-storms already manifesting in our changing world?
Yes. Unlike technology to terraform Mars, or even the Dust Bowl, the technology does already exist.
“There is a higher level wind turbine called a typhoon-resistant wind turbine with reference wind speed exceeding 57 m/s, which is the most robust and, correspondingly, the most expensive,” Zhao says. “Some offshore turbines – such as MySE 18.X–20 MW model from Mingyang Smart Energy – are designed to withstand loads up to 79.8 m/s, which suggests that even under current extreme wind intensities, certain turbines may still have the ability to survive severe events.”
That is encouraging, even though we have already reached Melissa winds of 80 m/s and, as we said, climate change has barely even gotten going yet. Meanwhile, thanks to studies like this one, “They” can start planning accordingly. It’s no use to climate change mitigation or us to build wind farms that collapse when the weather turns insane, as it has been doing.
While “They” mull the issue, since wind turbines can simply auto-shut down if necessary, is the chief problem we face one of flying turbines or loss of energy production?
It’s the flying turbines and the economic loss from that; how much power we are losing by turbines sullenly shutting down in high wind, or falling over, hasn’t been calculated.
“So far, we still think the extreme wind will cause huge risk in the safety of wind farms, not only the maximum wind speed, but also the high turbulence, high gust wind and high wind shear,” Zhao explains. “Since extreme wind from typhoons or extra-tropical cyclones typically lasts less than a day, and the number of such extreme storms rarely exceeds ten per year, the overall effect on annual power generation is relatively limited.”
At least they assume as much; no systematic assessment of generation loss caused by shutdowns during extreme wind events has been done yet, and meanwhile, climate change is just beginning.
