Floating wind turbine energy and fatigue loads estimation according to climate period scaled wind and waves

Abstract

Offshore wind power is one of the fastest-growing renewable energy sources, as it is expected to play a major role in the transition towards sustainability and net zero emissions. Despite its potential, the interaction of the turbines with the oceanic waves, especially in case of floating turbines, is one of the main drawbacks associated to it. In fact, mechanical oscillations caused by the waves could potentially alter the operation and lifetime of the turbines. Hence, while the characterization of the wind is sufficient for the long-term design of onshore wind turbines, the procedure is more complex in case of offshore turbines, since the height, period and direction of the waves will affect the lifetime of the turbine. In this paper, a methodology for the evaluation of the energy generation and fatigue mechanical loads of a Floating Offshore Wind Turbine (FOWT) considering a 30-year period is proposed. To that end, meteorological data from 1991 to 2020 are characterized using a cluster analysis and reduced into a computationally affordable number of simulation cases. Results show negligible energy loss of a FOWT due to interaction with the oceanic waves. However, a substantial increment of the mechanical fatigue in the side-side and fore-aft bending moments of the tower are detected. Such analyses might be applied for the predictability of the lifetime of an offshore wind turbine, as well as the selection of potential optimal wind farm locations, based on climatic patterns and the evolution of meteorological data.