China’s Dongfang Electric Hoists 26 MW Offshore Wind Turbine for Testing

Dongfang Electric Wind Power completed the hoisting of the 26 MW offshore wind turbine for testing on August 29 as the industry races forward with the huge next generation of turbines. It is one of several large offshore wind turbines currently in design or testing to break the 20 MW barrier and continues China’s emergence as the leader in the technology.

Western companies have generally stopped efforts at turbines above 18 MW, ceding the advancements to the Chinese. Mingyang Electric showed off its 20 MW turbine a year ago, as well as unveiling its efforts at a 26 MW giant. Dongfang previewed its 26 MW model last October, displaying the nacelle. The first unit was installed in Dongying, a city in northern Shandong province.

The company reports there were large challenges to overcome, including difficulties with aerodynamics and structural coupling. The unit consists of over 30,000 components and is designed for medium to high-speed wind areas. It says it is suited for wind speeds above approximately 18 mph (8 meters per second). 

 

Nacelle for the massive unit being raised into position (Dongfang)

 

The new unit is 31 percent larger than the 18 MW units and stands with its hub over 600 feet above the water level. It is reported to have a diameter of 310 meters (over 1,000 feet) with blades that are approximately 153 meters (502 feet) in length. Each rotation of the unit generates 62 kilowatt hours of electricity, and at average wind speeds of 22 mph, a single unit can produce 100 million kilowatt-hours annually. They report the design is also capable of withstanding a super typhoon with wind speeds of over 115 mph.

It employs a third-generation fully integrated semi-direct drive technology that combines the shaft system, gearbox, and generator. It is also fully sealed to prevent salt spray corrosion and incorporates internal and external cooling systems. Critically, they highlight that the control systems and key components are all domestically made.

Dongfang reports the unit is suited for operation in the 20 to 26 MW range. China, however, is yet to commercialize its largest wind turbines. Last December, Mingyang shut down tests on its 20 MW unit, acknowledging that two blades had fractured due to what were called “extreme, abnormal conditions,” according to Recharge News. 

China is believed to have reached 40 GW of installed offshore wind energy capacity, far ahead of any other nation. While the domestic market is booming, its manufacturers are also anxious to break into the Western market.