Self-Adjusting Wind Turbine Design helps China’s coastal wind farms withstand the destructive power of storms.
Super Typhoon Yagi, the second strongest tropical cyclone in the world this year, caused significant damage as it swept through southern China and Vietnam last weekend. However, while one Chinese wind farm was severely damaged, others remained intact. According to an expert, this is not surprising as storms are no longer an environmental burden for the development of wind power in China.
Some wind turbines toppled by Typhoon Yagi on Hainan Island. (Photo: Recharge).
Yagi produced winds of up to 245 km/h near its center when it made landfall in Wenchang, Hainan, China on September 6. A wind farm in the city was directly hit by the storm, causing several turbines along the coastline to topple. The farm was not operational at that time as it was undergoing upgrades to replace 32 small turbines with 16 larger, more storm-resistant turbines. The upgrade process began earlier this year and is expected to be completed in October. However, some newly installed turbines were destroyed by Typhoon Yagi. According to the parent company, Huaneng Hainan Power, at least 5 turbines were damaged. The cost of producing such a wind turbine is around several million USD.
Wind power generation involves using wind to rotate the blades of a turbine around a rotor, which drives a generator to produce electricity. When a strong storm approaches, turbines will automatically stop rotating their blades and then adjust their orientation through a pitch control mechanism, increasing wind resistance. However, the pitch control systems on these turbines were not operational due to the project not being handed over yet.
According to Qin Haiyan, Secretary-General of the China Wind Energy Association, a government non-profit organization, if the pitch control system fails and wind blows from the side, the wind resistance of the turbine will significantly decrease. Nevertheless, technological advancements have made such incidents less common in China.
Tropical cyclones are a familiar threat in many parts of the world and have long been a barrier to wind farm development due to their unpredictable nature and intense destruction. More than a decade ago, coastal wind turbines in China were sometimes devastated by storms, leading many to believe that the southern coastline, prone to storms, was unsuitable for wind power development. Yet, despite the increasing frequency and intensity of such storms worldwide in recent years, Chinese wind turbines are rarely destroyed. According to Qiu, this is thanks to China’s rapid advancements in storm-resistant wind farm design.
Typhoon Yagi brought heavy rain and winds of up to 17 on the Beaufort scale to southern China. Both onshore and offshore wind turbines in the coastal region were affected to varying degrees, but some premium turbines demonstrated excellent storm resistance, including a newly installed wind farm in Hainan with turbines from Mingyang Smart Energy, a major private wind turbine manufacturer in China.
The installation of a series of high-end turbines with a capacity of up to 20 megawatts (MW) and a super-light modular design was completed at the end of last month. Typhoon Yagi struck just days later, but the wind farm remained intact. According to a statement from Mingyang on September 8, the super turbine at the Hainan farm has a rotor diameter of 292 m, with a maximum swept area equivalent to 9 football fields. The larger rotor diameter enhances the swept area and electricity generation efficiency. The turbines are designed for deployment in areas with moderate to high wind speeds, particularly suitable for storm-prone regions. Mingyang stated that over 1,700 of its wind turbines across 51 farms have withstood the challenges posed by Typhoon Yagi. Mingyang’s turbines are very suitable for installation in deep sea areas and operate effectively at high wind speeds.
One wind farm in Guangdong Province, Mingyang Tiancheng, boasts the world’s largest single-unit floating wind turbine platform. This turbine array can adjust its pitch based on the storm’s direction, ensuring that the turbines always face into the wind.
After passing over Hainan Island on the afternoon of September 6, Yagi made landfall again in Cangwu, Guangdong, later that night. The first deep-sea floating wind turbine in China, named “Fuyao”, located in this area, was directly hit by the storm. According to the manufacturer, Haizhuang Windpower of China Shipbuilding Industry Corporation, the turbine withstood the storm for 5 hours. Fuyao is designed to endure typhoons, erosion, and other complex marine environmental conditions, having been tested through at least 3 strong storms.
Last year, China had over 160 wind farms in 12 coastal provinces, with a total installed capacity exceeding 29 million kilowatts, according to the China Renewable Energy Association.
