China installs world’s largest offshore converter: massive 3.1 GW of offshore wind capacity added to the grid

An offshore converter station, developed by China Three Gorges Corporation (CTG), was installed at CTG’s Rudong wind farm in east China’s Jiangsu Province. The 15-story-tall converter station is said to be the world’s biggest, and first of its kind in Asia.

The installation of the world’s largest offshore converter station was hailed by China Classification Society (CCS) as ‘a significant milestone’ in the development of deep-water wind power. The converter station commenced feeding power to the grid on 11 November 2021, and was fully connected on 25 December 2021.

The project boasts higher voltage class (±400kV) and larger transmission capacity than any other counterpart in the world. It can effectively address the issues of large capacity and long-distance power transmission facing offshore wind farms.

With 200 units of 3-MW wind turbines, the project has a total installed capacity of 800,000 kilowatts. Once fully operational, it will generate 2.4 billion kWh of electricity annually, enough to power about 1 million households of three. It can save about 740,000 tons of standard coal and reduce carbon dioxide emissions by about 1.83 million tons per year, helping China achieve the goal of reaching peak emissions and carbon neutrality.

CCS provided authentication and survey services for the China Three Gorges Corporation (CTG) Rudong offshore converter station, which is also an Asian first.

CCS’ expert team has been involved throughout the design, construction, transportation, installation, and commissioning stages of the pioneering project.

Fan Qiang, Vice President of CCS, attended the official delivery ceremony for the platform at Shanghai Zhenhua Heavy Industries (Nantong) Co Ltd with several senior CCS team members.

Mr. Fan said: “The instillation of RUDONG offshore converter station is a significant milestone in the development of deep-water offshore wind power development in China. We are very proud of all our team who have used their industry-leading expertise to support the delivery of this complex construction project.”

CCS says the facility effectively addresses the challenges of large capacity and long-distance power transmission presented by offshore wind farms. RUDONG is the first offshore ±400 kV wind power flexible DC transmission project in China. The station will be used to collect 1,100 MW of electric energy from three windfarms (H6, H8, H10) in the JIANGSU RUDONG project in China’s Yellow Sea.

The station will then convert the electricity into DC power and transmit it onshore, a distance of around 100km, the longest off-shore transmission length in China, via a submarine cable. When the project is in full operation it will be able to provide around 1.36 million households with their annual electricity consumption, helping China to move further towards its ‘2060’ double carbon reduction target. Compared with coal-fired power plants with the same capacity, the JIANGSU RUDONG windfarms project in the Huangshayang sea area, can save about 740,000 tons of standard coal and reduce about 1.83 million tons of carbon dioxide per year.

The converter station itself weighs 22,000 tons and is as tall as a 15-storey residential building. The impressive structure has an area that is nearly as large as a standard soccer pitch.

Mr. Fan said the official launch of the giant station marks another chapter in the continuing development of CCS’ industry-leading expertise in the growing offshore wind power sector.  CCS has now completed successful classification surveys for more than 60 wind power installation platforms and has carried out authentication surveys for more than 40 offshore substations. Mr. Fan said CCS is working “hand in hand” with the offshore wind power industry to continue its safe development and growth. 

As one of the leading classification societies in the offshore sector, he said CCS had “gained rich engineering experience” and established high technical standards through the large number of projects it has been involved in.

The RUDONG converter station, which was commissioned by CTG, was jointly constructed by Three Gorges Energy, China General Nuclear New Energy Holding Co., Ltd. and Shanghai Zhenhua Heavy Industries Co., Ltd.

China remains at the forefront of offshore wind power development and technology. A report earlier this year by the Global Wind Energy Council (GWEC) revealed that it was responsible for half of the world’s new offshore wind capacity in 2020.

The GWEC report also highlighted that the global offshore wind industry had its second-best year ever in 2020, despite the challenges of Covid-19, installing more than six GW of new capacity.

CTG reported:

1. the 1.7-GW Shapa offshore wind farm near Yangjiang in China’s southern province of Guangdong was connected on 25 December 2021;
2. the 1.1 GW Rudong offshore project involving 3 wind farms (H6, H8, H10) in the eastern-central coastal province of Jiangsu was connected on 25 December 2021;
3. the 300-MW (H8-2) offshore wind farm in Dafeng, Jiangsu province was connected on 25 December 2021;

Sources:

• Ocean News,  August 9, 2021. https://www.oceannews.com/news/energy/installation-of-world-s-largest-offshore-converter-station-in-asia

• CTG, 11 Nov 2021. https://www.ctg.com.cn/en/media/press_release/1242878/index.html

Renewables Now, 4 Jan 2022. https://renewablesnow.com/news/china-three-gorges-fully-commissions-3-offshore-wind-projects-767993/