Why Only One Chinese Wind Farm Was Damaged by Typhoon Yagi

Super Typhoon Yagi, the world’s second-strongest tropical cyclone this year, caused extensive damage as it swept through southern China and Vietnam last weekend. But while one Chinese wind farm was severely damaged, others remained standing. This is not surprising, according to a Chinese expert, as the storm is no longer an environmental burden on China’s wind power development.

Yagi had winds of up to 245 km/h near its center when it made landfall in Wenchang City on China’s Hainan Island on September 6. A wind farm in the city was directly hit by the storm, causing several turbines along the coastline to collapse. The farm was not operating at the time because it was undergoing an upgrade to replace 32 small turbines with 16 larger, more storm-resistant ones. The upgrade began 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 were damaged, according to the owner, Hainan Huaneng Power Generation Company. The cost of making such a wind turbine is in the millions of dollars.

Wind power generation involves using wind to rotate the blades of a turbine around a rotor, which drives a generator to generate electricity. When a strong storm hits, the turbine automatically stops rotating its blades, then adjusts its direction using a yaw control mechanism, which increases wind resistance. However, the yaw control system on the turbines is not yet operational because the project has not been handed over.

If the regulator fails and the wind blows from the side, the wind resistance of the turbine will be significantly reduced, said Qin Haiyan, secretary general of the China Wind Power Association, a government-affiliated nonprofit. However, technological advances 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 destructive power. More than a decade ago, China’s coastal wind turbines were occasionally damaged by typhoons, leading many to believe that the storm-prone southern coast was unsuitable for wind power development. But despite the increased frequency and intensity of such storms around the world in recent years, China’s wind turbines have rarely been destroyed. Qiu attributes this to China’s rapid progress in typhoon-resistant wind farm design.

Typhoon Yagi brought heavy rain and force 17 winds to southern China. Both onshore and offshore wind turbines in coastal areas were affected to varying degrees, but some high-end turbines showed 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 new ultra-light modular design was completed late last month. Typhoon Yagi hit a few days later, but the wind farm remained intact. According to an announcement by Minh Duong Company on September 8, the super turbine at the Hainan farm has a rotor diameter of 292 m, the maximum swept area of ​​the blade is equivalent to 9 football fields. The larger rotor diameter increases the swept area and power generation efficiency. The turbines are designed to be deployed in areas with medium to high winds, especially suitable for areas with frequent storms. According to Minh Duong, more than 1,700 wind turbines of the company in 51 farms have overcome the challenge of Typhoon Yagi. Minh Duong’s turbines are very suitable for installation in deep sea areas and operate at high wind speeds.

A wind farm in Guangdong province, the Mingyang Tiancheng, has the world’s largest single-capacity floating wind farm. The turbines can adjust their yaw based on the direction of storms, so that the turbines always face the direction of the wind.

After passing Hainan Island on the afternoon of September 6, Yagi made another landfall in Xuwen, Guangdong, at night. China’s first deep-sea floating wind turbine, “Fuyao”, installed in the area, was directly hit by the typhoon. According to its manufacturer, Haizhuang Windpower of China Shipbuilding Industry Corporation, the turbine withstood the typhoon for five hours. Fuyao is designed to withstand typhoons, erosion and other complex marine environmental conditions, and has been tested through at least three strong typhoons.

Last year, China had more than 160 wind farms in 12 coastal provinces, with a total installed capacity of over 29 million kilowatts, according to the China Renewable Energy Association.