Performance analysis of two generations of heaving point absorber WECs in farms of hexagon-shaped array layouts

Paper in proceeding, 2022

Wave energy has attracted increasing attention due to the transition to electricity generation of renewable energy sources. To achieve cost-efficient solutions for the commercial market of electricity generation, wave energy converters (WECs) must be deployed in wave energy farms. The array layout needs to be carefully designed, specifically for each WEC technology, since hydrodynamic interaction effects (absorption, radiation, and diffraction of waves) between the WECs affect the performance of each WEC and, therefore, the electricity generation of the entire wave energy park. This study presents a numerical methodology that can realistically simulate wave energy farms with floating wave energy point absorbers installed in arrays. The numerical models, developed in the DNV software package SESAM, can simulate and compare various environmental conditions and design changes for a WEC, regarding the overall performance and characteristics of single WECs and the entire wave energy park. The methodology is applied to case studies for two generations of the WEC WaveEL developed by Waves4Power. Two farm designs with hexagon array layouts deploying six WEC units are proposed. Parametric studies are presented to analyze, e.g., the hydrodynamic power performance and the levelized cost of electricity (LCoE), where the two WaveEL generations, the dimensions of hexagon-shaped array layouts, environment conditions, and the wave encounter direction are varied and compared. The hexagon layouts are also compared with a previous layout, StarBuoy, with 10 units. The study verifies the conclusion from similar studies that interaction effects can have both positive and negative influences on the LCoE. It provides recommendations for hexagon-shaped array layouts that lower the LCoE due to hydrodynamic interaction effects.