For deeper water projects in southern China, meanwhile, typhoon risks may be high, according to Junfeng. In 2003, Typhoon Maemi severely damaged all six turbines in a Japanese wind farm on Miyakojima Island near Okinawa. Wind gusts up to 90 meters per second buckled towers on two turbines, uprooted the foundation of a third, and broke the blades off the rest.
And Miyakojima’s turbines were relatively small compared to the turbines planned for China’s offshore developments. Several manufacturers, including Sinovel and Xingjiang-based Goldwind, are building five-megawatt machines.
Chinese manufacturers have their work cut out for them to demonstrate that they can build equipment robust enough to stand up to offshore operation. Quality shortcomings are rife in the Chinese turbine industry. As a 2009 report on the Chinese market for clean energy technologies by the China Greentech Initiative put it last year: “Real and perceived quality issues for Chinese domestically manufactured turbines and components negatively impact wind farm efficiency and constrain export market opportunities.”
Those concerns were highlighted last fall by the delivery of faulty monopole foundations by a Chinese manufacturer for the U.K.’s 500-megawatt Greater Gabbard offshore wind farm. U.K. utility Scottish and Southern Energy acknowledged in February that quality defects in the 65-meter long, 650-ton steel piles had delayed its project.