Preliminary Design Methodology Based on Numerical Optimization of Offshore Wind Turbine on a Monopile With Application in Offshore Brazil

Abstract This paper proposes a preliminary design based on the numerical optimization of offshore wind turbines on a monopile to define the main dimensions of offshore operation in Brazil. As investments in wind turbines have increased substantially in recent decades, the correct design of these structures for operating in offshore conditions with techno-economic excellence must be done. Moreover, this must comply with the classification societies’ requirements. The optimization procedure proposed in this work focuses on high-power capacity (about 15 MW) wind turbines. Hence, the work has developed an algorithm to determine the foundation characteristics so that the offshore device attends to the ultimate limit state (ULS), serviceability limit state (SLS), and fatigue limit state (FLS). It shows the feasibility of such a project in the Brazilian offshore scenario. Case studies are considered to define those dimensions for operating in Brazil based on meteoceanographic data and geotechnical information. Specifically, the work follows the requirements from the DNV’s (Det Norske Veritas) regarding the ultimate loads, soil loads, the natural frequency of the system, and fatigue life.