Abstract
Wave energy converters (WECs) have the potential to be major players in the renewable energy sphere. WEC arrays are well suited for grid-scale energy, offshore aquaculture, water desalination, coastal communities, and other niche applications. Understanding the effect of an array on the surrounding wave field is crucial to accurate modeling, determining interactions between each individual WEC, and finding power output. Array configuration and WEC geometry can alter power output, either constructively or destructively. This study models different configurations and WEC geometries in a 4-WEC array using a Boundary Element Method (BEM) solver. The geometries considered are heaving sphere and cylinder point absorbers. The software considers the bodies to be fixed while altering the incoming wave field. The calculations analyze the perturbed wave field and power output by determining radiation and diffraction effects from the array as well as body motion. Two power take-off (PTO) schemes are considered to analyze energy extraction. Obtained results show that regular arrays (1 × 4) of all geometric configurations tend to have milder effects on the wave field. When mixing geometries in the 1 × 4 arrays, similar levels of disturbance are found, but the wake lacks symmetry. Arrays with multiple rows (2 × 2) display higher disturbances. Inline array configurations, where WECs are placed directly behind each other relative to the incoming waves, are most sensitive to varying geometries. All regular arrays demonstrated constructive effects on power output, while the staggered configurations displayed the greatest degree of destructive effects. To extract the most energy, an optimized spring-damper is preferred, but this is more challenging to realistically implement. If the designer’s primary goal is increasing array efficiency, the regular array formation is most favorable. However, if the designer looks to decrease ocean space used, potentially share mooring lines, and produce meaningful energy, the inline formation is a reasonable choice.
