Chinese Wind Power Heads Offshore
Breezy tidal flats offer green power on the doorstep of China’s bustling seaboard.
China’s first offshore wind farm, a 102-megawatt array that’s set to come to full power this month in the Yangtze River delta near Shanghai, looks to be the start of something big. Chinese officials announced plans last month to request bids for three to four large-scale offshore wind power projects generating up to 1,000 megawatts total. Beijing-based energy consultancy Azure International predicts that China will install 514 megawatts of offshore wind over the next three to four years, and by 2020 will have invested $100 billion to install up to 30,000 megawatts. That’s equal to all of the onshore wind farms currently installed in China, already the world’s largest market for wind power.
China’s offshore winds are slower than Europe’s because they cross Asia before striking out to sea, whereas the North Sea’s winds travel an unimpeded transatlantic path. But 40 percent of China’s population lives along the eastern seaboard. China is building a transmission supergrid to bring in hydroelectric, coal, and wind power from western China, but Meyer says leaders of coastal provinces see offshore development as a means of local investment. “China still has a very locally protectionist economy. There’s an interest from provincial governments to support the coastal economy and jobs by supporting a wind industry in their backyard,” says Sebastian Meyer, Azure’s research director.
The Chinese offshore wind situation is analogous to that in the United States, where eastern states advocate offshore wind over construction of an interstate supergrid delivering western wind power. For example, last week, Cape Wind, which has proposed a wind farm off Nantucket, announced it had ordered 130 turbines. The difference is that China’s first offshore wind farm, installed by top Chinese turbine producer Sinovel, is about to start generating electricity, whereas Cape Wind has been waiting for its federal permit since it gained state and local permits in 2008. U.S. Interior Secretary Ken Salazar has promised a decision on Cape Wind by the end of this month. China’s National Energy Administration and National Oceanic Administration issued joint regulations for offshore wind farm development in January in a bid to accelerate the industry.
Li Junfeng, deputy director of China’s Energy Research Institute in Beijing, indicated in a presentation to an offshore wind seminar in Norway last month that near-term development would focus on the 100 to 200 gigawatts of wind energy potential available in extensive tidal flats. She highlighted Jiangsu Province, north of Shanghai, which has eight to 10 gigawatts of intertidal wind power potential. Jiangsu is the only coastal site among six regional wind power development centers designated by Beijing last year. Each site is slated to receive at least 10 gigawatts of installation by 2020.
Jiangsu’s first offshore pilot-scale farms are under construction: a 30-megawatt project by Longyuan Group and a six-megawatt project developed by Hebei-based China Three Gorges Project. In February, Beijing-based Shenhua Guohua Energy Investment, a subsidiary of China’s largest coal producer, announced it was considering two 300-megawatt offshore projects in Jiangsu that would use 3.6-megawatt turbines under development by Shanghai Electric Wind.
A key technical challenge is engineering for the tidal flat’s muddy seafloors and shifting sandbars, which require different foundations and installation vessels than those developed for the North Sea. Guohua, for example, is developing a novel steel pile foundation for its Jiangsu wind farms. Rather than the single steel monopoles common for North Sea projects, Guohua’s will employ five piles, each 56 meters long.
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.
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September 11-14, 2018
MIT Media Lab