Suction bucket jacket foundations are novel foundation solutions for bottom-fixed offshore wind farms and are gaining popularity in China. However, in many Chinese offshore wind farm sites, layered clay and sand ground conditions are frequently encountered which pose installation risks for suction bucket foundations. This paper presents recent installation experience of two suction bucket jackets in Southern China with an aim to provide guidance to future installations in similar soil conditions.
The offshore wind industry is fast-growing in China due to the government's push for energy structure transition and commitment to the strategic goal of carbon peaking in 2030 and carbon neutral in 2060. In 2021, China saw an added offshore wind capacity of 12 GW and the total accumulated capacity reached 23 GW by the end of 2021. Strong growth is projected in the coming years and the total installed capacity is forecasted to reach 40 GW by the end of 2026.
Suction bucket jacket (SBJ) is a relative new support structure type for bottom fixed offshore wind farms. It offers several advantages over conventional jacket structures on piles due to its efficient installation with the jacket and bucket foundations installed in one go and its superior adaptability to sites with shallow bedrock. The first of its type in typhoon-prone offshore Southern China was installed in August 2020 (Liu et al. 2020) and several new projects with either a single demonstrator (Houhu Offshore Wind Farm), small scale application (Yuedian Shapa Offshore Wind Farm with six turbines on SBJ) and mass application (Fujian Changle Offshore Wind Farm with 72 turbines on SBJ) are installed since then. With the industry expanding to deeper waters (>35m) and greater distance to the shore and application of larger wind turbines (10+ MW), more and more offshore turbines will be supported by jacket structures and a large portion of them are expected to be supported by suction bucket jackets.
