World’s largest offshore converter to deliver 6 billion kWh of clean power a year

China has just installed the world’s largest offshore converter station off the coast of Guangdong, which is set to transmit roughly six billion kilowatt-hours (kWh) of clean electricity every year Known as the ‘Heart of Offshore Wind” the massive platform will collect electricity generated by offshore wind farms and efficiently deliver it to the mainland grid. It was installed on Thursday, July 23, about 62 miles (100 kilometers) from the coast of Yangjiang in the South China Sea. The facility is reportedly the world’s first 500-kilovolt (kV), 2,000-megawatt (MW) flexible direct current (DC) offshore converter station. The project has now moved into the final phase of subsea cable installation and offshore-onshore joint testing before commercial operation starts. Once fully commissioned, it is expected to reduce carbon dioxide (CO2) emissions by nearly five million metric tons annually. It took about seven hours to complete the installation. Record-breaking converter station China’s State-owned Assets Supervision and Administration Commission (SASAC), which is responsible for managing state enterprises, disclosed that the converter station is made up of two massive structures. The first one includes a seven-story steel superstructure. The second is a jacket foundation anchored to the seabed. The upper platform is 280 feet (85.5 meters) long, 271 feet (82.5 meters) wide and 144 feet (44 meters) tall. It weighs about 25,000 metric tons. It is supported by the jacket foundation, which measures 269 feet (82 meters) long, 187 feet (57 meters) wide and 226 feet (69 meters) high. The structure weighs 17,000 metric tons. The Heart of the Sea Wind converter station.Credit: sasac.gov.cn At the same time, the structure is also secured to the seabed by a total of eight foundation piles. These are designed to withstand strong winds, powerful waves, ocean currents, corrosive saltwater, dense sea fog and frequent typhoons. The converter station’s enormous weight far exceeded the lifting capacity of any domestic vessel, forcing engineers to develop an innovative installation method. This is why engineers adopted an approach known as “float-over” installation. Built to endure Instead of lifting the massive steel platform directly into place, the engineers used the semi-submersible heavy-lift vessel, Xiang Tai Kou. They then slowly positioned the structure over its jacket foundation. The process relied on the tidal movements and the vessel’s dynamic positioning system to guide the platform into place with remarkable precision. During the operation, the clearance between the upper structure and the foundation was only six inches (150 millimeters) on each side. Meanwhile, the rubber fenders and specialized coupling devices installed on the foundation legs helped absorb potential impacts. They also ensured the platform aligned safely before being secured. The installation took seven hours to finalize. Project teams closely monitored forecasts from multiple weather services before selecting an installation window with favorable wind and sea conditions. The operation began shortly after 7 am on June 4. “The Heart of the Sea Wind converter station has the world’s highest voltage and largest transmission volume of offshore wind power, flexible DC transmission projects,” SASAC revealed in a press release. Once operational, it will deliver six billion kWh of clean electricity annually while cutting CO2 emissions by nearly five million metric tons. Recommended ArticlesGet the latest in engineering, tech, space & science - delivered daily to your inbox.Based in Skopje, North Macedonia. Her work has appeared in Daily Mail, Mirror, Daily Star, Yahoo, NationalWorld, Newsweek, Press Gazette and others. She covers stories on batteries, wind energy, sustainable shipping and new discoveries. When she's not chasing the next big science story, she's traveling, exploring new cultures, or enjoying good food with even better wine.