Four crew members are still missing after a wind turbine installation vessel capsized during construction operations at China Guangdong Nuclear Power’s 400MW Huizhou offshore wind project off the coast of southern China’s Guangdong province.

The vessel, Shengping 001, owned by Tianjin Jincheng Offshore Engineering, was left listing in the water after colliding with a wind turbine monopile foundation about 30km offshore at noon on Sunday, said the Guangdong Maritime Rescue Centre (GMRC).

There were 65 crew onboard, with 61 evacuated and four still missing as of Monday. GMRC has mobilised almost 30 vessels and helicopters in the rescue operation.

The global offshore wind industry has seen several vessel-related accidents over the past few years, including in China, the UK, Germany and Taiwan, but this incident appears to be the most serious yet.

Shengping 001 had been a liftboat known as Teras Fortress 2, until it was converted into a wind turbine installation vessel by Huangpu Wenchong Shipbuilding Industry in mid-June.

The 92-metre vessel had been chartered by SEPCO Electric Power Construction Corporation, the contracting unit of Shandong province-based Power Construction Corporation of China.

Chinese offshore wind operators are rushing to complete projects by the end of this year in order to be eligible for a national subsidy of 0.85 yuan ($0.13) per kWh.

Guangdong, which borders Hong Kong, is leading China’s offshore wind expansion with plans to install 4GW by the end of this year and 18GW by 2025.

China currently has a market-leading 4.4GW of offshore wind under construction, according to data from advocacy body the World Forum for Offshore Wind, as well as over 7GW in operation and as recently as 2019 was targeting having over 40GW installed by 2022.

· A version of this article first appeared in Recharge's oil & gas sister publication, Upstream