Analysis of Power Performance and Mooring Fatigue Damage for Wave Energy Parks

Licentiate thesis, 2023

Wave energy has been recognized as a promising alternative to traditional energy sources due to its cleanliness and sustainability. To harness this energy, wave energy converters (WECs) are utilized. These WECs operate using a variety of working principles and are typically deployed in large numbers in the form of wave energy parks to generate electricity with high efficiency and low levelized cost of energy (LCOE). However, the interaction effects between multiple WECs can positively or negatively impact power performance and mooring fatigue damage, highlighting the importance of numerical methodologies to evaluate such effects and facilitate agile wave energy park design processes.

The primary objective of this thesis was to develop numerical methodologies and data post-processing techniques to effectively access single WECs and wave energy parks consisting of two different WEC concepts belonging to the point absorber group: WaveEL and NoviOcean. Specifically, two methodologies were built based on the potential theory and a computational fluid dynamics (CFD) method, for which the boundary element method (BEM) and direct numerical simulation (DNS) with volume of fluid (VOF) modelling were adopted, respectively. These methods were implemented using the software, DNV SESAM and STAR-CCM+. The WEC concepts were evaluated in terms of the performance and mooring fatigue damages of each WEC concept with varying WEC generations, wave conditions, wave incoming directions and wave park layouts.

This thesis contributes to a better understanding of WEC system modelling, power performance and mooring fatigue damage estimation. Ultimately, these findings are anticipated to facilitate the development of optimized wave energy park layouts in the future.