Logistics and transportation study of floating wind farm foundations: analysis of challenges and consequences on project phases.

Floating offshore wind is emerging as a key solution for expanding renewable energy generation in deep-sea areas and exploring locations far from shore and human activities corridors, where traditional fixed-bottom turbines are not technically feasible and interferences are minimized. Its scalability and high-capacity potential make it a strategic technology in the global energy transition. However, the development of such technology is complex and exposed to multiple risks, among which logistic and scheduling ones are highly critical. The study focuses on a real-case scenario involving 35 floating wind turbines to be installed in the North Sea on an Italian EPCI contractor patented foundation. Two alternative transport approaches were evaluated: (1) shipping individual megablocks, i.e. foundations subparts, and (2) transporting fully pre-assembled floaters from East Asia to Europe. A technical assessment was conducted on vessel requirements, port infrastructure, and spatial constraints on temporary storage areas. Heavy transport vessel availability was analysed upon deck carriers and semi-submersible vessels market database. Furthermore, a study was performed through Gantt Charts to simulate the base case project schedule and various sensitivity analyses on transport vessels availability rather than different project phases delays. The results show that transporting pre-assembled floaters reduces yard-side operations and accelerates installation readiness, but heavily relies upon a limited number of semi-submersible vessels, which are mandatory to cope with pre-assembled floaters scenario. In contrast, the megablocks option offers more flexibility in vessel sourcing but increases onshore complexity and exposure to schedule delay risks, due to an increased number of assembly operations. The sensitivity analysis, performed on the first option, shows that even minor disruptions can lead to a significant cumulative delay which may heavily affect the project overall schedule. Highlighting the importance of potential operational interferences risks and consequences. The study pushes for the development of a structured decision-making framework for offshore wind logistics, emphasizing the importance of dynamic planning, port infrastructure readiness, and supply chain resilience as critical enablers for the scalable deployment of floating wind technologies.