As Republic of Korea (Korea, hereafter) moves towards “net zero carbon emission” by 2050, wind power generation is considered as one of the key elements to achieve the goal. Korean government plans to reach 12GW installed offshore wind capacity by 2030. The plan includes the construction of a 6GW floating offshore wind farm in the Dong-Hae area off the coast of Ulsan in water depths ranging from 120 to 180m.
A floating offshore wind turbine substructure is being developed with a focus on the Korean market. It consists of semisubmersible type platform with three columns of pentagonal shapes connected by three pontoons. The design philosophy is to have a construction-friendly structure for smaller Korean shipyards, minimal requirement for offshore installation vessel fleet and a robust and passive design that requires minimum maintenance over the operation period. The column sections are similar to that of small fishing vessels and pontoon section is similar to barge, both of which are familiar to the small Korean shipyards for construction. Hull structures are optimized to support a 15MW wind turbine safely through a thorough time-domain response-based structural analyses and assessment.
This paper presents the key features and functionalities of the design, an overview of the hull and mooring performance and a preliminary construction and installation plan.