The blades of the world’s largest wind turbine, currently being tested off the coast of China, are more than twice the wingspan of a Boeing 777. It can generate 26 megawatts (MW) of power, more than double the global average for individual turbines. But its record is about to be shattered: Southern China-based Ming Yang Smart Energy has announced another twice as powerful offshore wind turbine.
According to the company, which plans to start production of the turbine later this year and deploy it next year, the 50 MW large structure is designed to float on the surface of the ocean and withstand typhoons.
While Western manufacturers such as Siemens Gamesa are also pushing for ever-larger turbines, the trend is particularly dominant in China after the government imposed a 2022 stopped subsidizing offshore wind farms, forcing developers to find ways to save money. Using larger turbines means fewer will be needed to generate the same power, says Zhu Ronghua, director of the Yangjiang Offshore Wind Energy Laboratory, a research institute supported by the government of China’s Guangdong province. “You can save on transportation, construction and installation fees, which account for 70-80 percent of the construction cost of an offshore wind farm,” Zhu says.
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Two-head turbines
In general, a larger capacity turbine is also physically larger. This is because you need longer blades to catch more wind and produce more electricity. The current record-breaking turbine, made by Dongfang Electric, is so huge that its tower is the height of a 63-story skyscraper.
But Ming Yang takes a different approach: his megamachine will have not one, but two sets of motors and blades, each capable of generating 25 MW of power. They are supported by a Y-shaped tower on a single platform. Each of its blades is 145 meters long, about three times the height of the Statue of Liberty. The design is based on the world’s first twin-head turbine, a 16 MW version currently operating in the South China Sea, and combines the power of two turbines into one. “If you’re lucky [at this scale]this model has the potential to be a game-changer in the offshore wind industry,” says Umang Mehrotra, offshore wind analyst at Norwegian research firm Rystad Energy.
Han Yujia, a renewable energy researcher at the California-based nonprofit Global Energy Monitor, is most impressed that Ming Yang intends to increase turbine capacity by more than 20 MW in one go, well ahead of the industry’s average growth rate of 2-3 MW annually.
Ming Yang says the 50MW turbine will have a “strong ability” to counter typhoons, but has yet to provide details on how it will do so. The 16 MW model, which is supposed to serve as a prototype, has survived many typhoons over the past year, including winds of more than 150 kilometers per hour from Typhoon Ragasa, says Wang Chao, chief designer of the model line, known as OceanX. Some of its resilience comes from the fact that it is tethered to the ocean floor at one point, allowing it to rotate 360 degrees “like a weathervane” and maintain its balance in strong winds, Wang says. This feature also means that the turbine can be installed in deeper waters, further from shore, where the winds are stronger and more consistent.
But the new model will be significantly larger, so there could be “a lot of risk,” says Mehrotra. Also, there can be technical difficulties in ensuring that the two rotors generate power smoothly because they are so close together on the same platform compared to the general spacing specifications of side-by-side turbines, he says. A representative for Ming Yang did not respond to requests for comment Scientific American.