Layout optimization of wave energy converter arrays in realistic wave climates

The production efficiency of a wave energy converter (WEC) array depends mainly on the array layout. Therefore, optimizing the array layout to maximize the energy production of WEC arrays is an important research topic in the field of wave energy. The limitations of existing works in terms of model accuracy, layout strategy, and wave climate constrain the applicability of optimization results. This paper thoroughly investigates the inherent relationships between wave climate, wave interactions, and array layout, considering practical WEC systems and general wave climates for the first time. The aim is to provide more universal guidance for the design of WEC arrays. First, a high-fidelity time-domain numerical model of a two-body WEC array is constructed using the boundary element method to accurately assess the interactions between devices in the array. Subsequently, a novel layout strategy is presented to enhance the optimization efficiency of the array layout. After validating the numerical model and layout strategy, a thorough layout optimization of arrays consisting of 4, 8, and 12 devices in diverse wave climates is performed. The paper specifically focuses on analyzing the annual mean power output and wave interactions of the obtained optimal layouts. The wave climates considered involve both unidirectional mean and multidirectional realistic climates from three potential deployment sites. The results show that the unidirectional climate assumption significantly overestimates the constructive interactions of arrays, and the optimal layouts obtained under this assumption is not applicable to multi-directional climates.