The Washington Post’s newly launched in-depth reporting service WP Intelligence recently reported that as offshore wind development expands and demand for cross-regional grid interconnections grows, high-voltage direct current (HVDC) subsea cables are increasingly becoming a key technology for the global energy transition and the modernization of power grid infrastructure. However, China’s rapid expansion in this sector could allow it to control around 80% of global excess manufacturing capacity in the future, raising potential supply chain risks. The report cited comments from Bo-Xiang You, Deputy Director of the Energy Security and Climate Resilience Program at DSET.
The report noted that breakthroughs in insulation materials and power electronics over the past decade have significantly improved the transmission capacity of subsea power cables, making long-distance subsea electricity transmission increasingly commercially viable. At the same time, the global subsea cable supply chain is facing severe capacity constraints. Advanced subsea cable manufacturing facilities are already oversubscribed, and with only around 60 specialized vessels worldwide capable of laying and maintaining subsea cables, many large-scale grid interconnection and offshore wind projects are facing tight construction schedules.
Currently, the United States still relies heavily on imports for advanced HVDC subsea cable systems, with most manufacturing capacity concentrated among European firms. Although the European cable manufacturer Nexans established the first U.S. subsea HVDC cable plant in 2021, and South Korea’s LS Cable & System is building a large subsea cable manufacturing facility in the country, the overall industrial scale remains limited. In addition, uncertainty surrounding offshore wind policies has hindered some manufacturing investments. For example, the Italian cable manufacturer Prysmian had planned to build a plant in Massachusetts but ultimately cancelled the project due to uncertain market prospects.
Meanwhile, the report pointed out that China has been rapidly building a comprehensive subsea cable industrial ecosystem and could emerge as a dominant player in the global market. Supported by national policies and industrial investment, Chinese companies are now capable of producing advanced subsea cables with voltages of 600 kilovolts or higher, while establishing a vertically integrated supply chain that includes copper and aluminum conductors, insulation materials, converter equipment, and cable-laying vessels. China’s large-scale offshore wind development also provides a stable domestic market, allowing companies to expand production capacity and accumulate engineering experience.
You noted that demand for subsea HVDC cables across manufacturing, deployment, and installation is currently facing extremely tight timelines, particularly in the post-pandemic period, and added that Chinese corporations have more capacity for manufacturing, and have expanded their overseas presence to fill those gaps.
The report also highlighted that China now accounts for more than half of global offshore wind capacity, which has helped drive rapid growth in its subsea cable industry. According to commodity research firm CRU, Chinese manufacturers could account for over 80% of global excess HVDC cable manufacturing capacity by 2030. As Chinese firms actively establish manufacturing bases and partnerships in emerging markets such as the Middle East, their influence over the global subsea power transmission infrastructure supply chain is likely to continue expanding.
The report concluded that to avoid repeating the trajectory of the solar industry, where China quickly gained dominance in global manufacturing, the United States and its allies should treat HVDC subsea cables as critical infrastructure. This would include strengthening domestic manufacturing capacity, expanding cable-laying vessel fleets and workforce training, and coordinating supply chains more closely with partners such as Europe, Japan, and South Korea to ensure the resilience and security of cable supply chains needed for future grid development and the global energy transition.
