Super Typhoon Yagi – the world’s second most powerful tropical cyclone this year – left a deadly trail of destruction as it swept across southern China last week.

However, while one wind farm was badly wrecked – the rest stood strong.

This came as no surprise to one Chinese wind energy expert, who said: “Typhoons are no longer an insurmountable environmental constraint for China’s wind power development”.

Yagi packed winds of around 245km/h (152mph) near its centre when it made landfall on Friday in Wenchang, in China’s southern island province of Hainan. A wind farm in the city was hit head-on, leaving several turbines lined up along the coastline battered and broken.

The farm was not in operation at the time, as it is undergoing an upgrade that will replace 32 small wind turbines with 16 larger and more efficient typhoon-resistant versions.

 

Work started earlier this year and was expected to be completed in October. But some of the newly installed turbines were destroyed by Yagi.

At least five turbines had been torn down, a representative from farm owner Huaneng Hainan Power Generation Co told mainland media. The company is a subsidiary of state-owned energy firm China Huaneng Group.

Shanghai-based financial news site Yicai quoted an industry insider as saying that the manufacturing cost of a single wind turbine of this model was close to tens of millions of yuan, the equivalent of millions of US dollars.

Wind power generation involves using the wind to turn the propeller-like blades of a turbine around a rotor, which then spins a generator to produce electricity.

When a strong typhoon hits, the turbine will automatically stop its blades from rotating and then adjust its direction using a yaw control mechanism to reduce wind resistance.

But the yaw system on these turbines was not working because the project had yet to be commissioned.

According to Qin Haiyan, secretary general of the Chinese Wind Energy Association, a government non-profit organisation, if the adjustment system fails and the wind blows in from the side, the wind resistance of a turbine is greatly reduced.

However, technological advances have made such incidents less common in China, Qin told mainland media outlet Jiemian on Sunday.

Tropical cyclones – called typhoons or hurricanes depending on the region – are a familiar threat in certain parts of the world and have long deterred wind farm developers because of their unpredictable and catastrophic nature.

 

Qin recalled that more than a decade ago, China’s coastal onshore wind turbines would sometimes be damaged by typhoons, leading many to believe that its typhoon-prone southern coast was not suitable for wind power development.

But despite the increasing frequency and intensity of such storms worldwide in recent years, “Chinese wind turbines are rarely destroyed,” Qiu noted.

He attributed this to China’s rapid progress in typhoon-resistant wind farm design.

Yagi hit southern China with lashing rain and winds of up to level 17, the highest on China’s tropical cyclone scale. Both onshore and offshore wind turbines in coastal areas were affected to varying degrees, but some cutting-edge turbines showed excellent typhoon resistance.

Among them was a newly installed wind farm in Hainan featuring turbines from Mingyang Smart Energy, a major private wind turbine manufacturer in China.

They include what the company claims is the “world’s largest single-capacity offshore wind turbine”.

Installation of the advanced turbines – with a capacity of up to 20 megawatts and a modular, lightweight design – was completed only at the end of last month. Yagi arrived days later, but the wind farm survived.

Mingyang issued a press release on Sunday about the outstanding typhoon resistance of its turbines.

According to the release, the mega turbine at the Hainan farm has a rotor diameter of 292 metres (958 feet), covering a maximum wind-sweeping area equivalent to nine football pitches. The bigger rotor diameter boosts the wind energy capture area and accordingly increases power generation efficiency.

The turbine is designed for global deployment in medium-to-high wind speed regions, and is particularly suited to typhoon-prone sites, Mingyang said in the press release.

It said more than 1,700 of its wind turbines across 51 wind farms survived the challenge of Yagi.

The company, a world leader in typhoon-resistant technology, says its turbines are well-suited for installation at deep-sea sites and for operation in high wind speed areas.

A wind farm in the southern province of Guangdong hosts another model from the company, the Mingyang Tiancheng – which it describes as “the world’s largest monolithic floating wind power platform”. It has the ability to make adaptive yaw adjustments based on the direction of the typhoon, so that the turbine is always square to the direction of the incoming wind.

With its abundant wind resources and cost advantages in offshore wind power, China leads the world in operational offshore wind capacity and dominates global wind turbine manufacturing.

After Hainan on Friday afternoon, Yagi made landfall again in Xuwen, Guangdong, during the night.

China’s first deep-sea floating wind turbine, “Fuyao”, installed in the Xuwen sea area, took a direct hit. According to its manufacturer – the state-owned China State Shipbuilding Corporation Haizhuang Windpower – it withstood the hurricane force winds for up to five hours.

The company said in a press release today that “Fuyao” is designed to withstand typhoons, corrosion and other complex marine environments, and has been tested by at least three strong typhoons.

As of last year, China had more than 160 offshore wind farms across 12 coastal provinces, with total installed capacity exceeding 39 million kilowatts, according to the China Renewable Energy Society, a Beijing-based research NGO.