On August 11, the 800-megawatt offshore wind project in Rudong, Jiangsu Province, operated by China Three Gorges Renewables, achieved a significant milestone by generating over 10 billion kilowatt-hours of electricity. This marks the first offshore wind farm in Asia to utilize flexible direct current (DC) transmission technology for power delivery, providing practical validation for the large-scale application of flexible DC transmission in long-distance offshore wind power.
The project, situated in the Huangshayang sea area off the coast of Rudong, boasts a total installed capacity of 800 megawatts. It is complemented by the construction of Asia's first offshore flexible DC converter station, which was fully commissioned and connected to the grid in 2021. Flexible DC transmission can be likened to an "intelligent transmission aorta" for offshore wind power, capable of carrying high-capacity electricity over long distances while actively smoothing out the intermittent fluctuations inherent in wind power generation, thereby ensuring stable integration into the power grid.
To date, the facility has operated safely and stably for over 1,600 days, achieving a remarkable equipment availability rate of 99.5%. Wang Xuefeng, deputy general manager of the Nantong subsidiary of China Three Gorges Group's Jiangsu branch, noted that the project had no mature precedents to follow. The team focused on resolving challenges such as the stable operation of the ±400 kV flexible DC system, monitoring and maintaining long-distance submarine cables, and regulating under high-load conditions. Compared to traditional AC transmission methods, the project has reduced transmission line losses by approximately 1.2 percentage points, resulting in cumulative savings of over 735 million yuan in transmission costs.
As China's offshore wind development extends further into deep-sea areas, with increasing distances from the shore and rising transmission capacities, the technical limitations of traditional AC transmission have become more apparent. Flexible DC transmission, with its large capacity, low loss, and flexible control capabilities, is better suited to meet the delivery needs of deep-sea offshore wind power. It is estimated that the 10 billion kilowatt-hours of clean energy generated can meet the annual household electricity needs of approximately 4 million homes, equivalent to saving 3 million tons of standard coal and reducing carbon dioxide emissions by 7.4 million tons, underscoring its significant energy-saving and emission-reduction benefits.