Wave energy converters in array configurations—Influence of interaction effects on the power performance and fatigue of mooring lines
Journal
Ocean Engineering
Journal Volume
211
Date Issued
2020
Author(s)
Abstract
In an array system of wave energy converters (WECs), hydrodynamic interactions between the WECs occur through the absorption, radiation, and diffraction of waves. The main objective of this study was to analyse the hydrodynamic interactions between floating point-absorbing WECs and the influence of this interaction on the power performance and fatigue life of the WECs’ mooring lines. The hydrodynamic and structural response of the WEC systems were analysed primarily using potential flow theory, the Morison equation, and continuum mechanics theory. Four 2-WEC models and two 10-WEC models, among which different separating distances and mooring configurations were considered, were investigated. The models were simulated for various environmental loading conditions. The results from each simulation were evaluated in terms of the power performance of each WEC, accumulated fatigue damage in each mooring line, and the levelised cost of energy (LCoE). The hydrodynamic interactions show a larger impact on the 10-WEC simulation models. To account for the hydrodynamic interactions in the simulations using the 10-WEC models, the fatigue damage in the mooring lines is varied at an average of 15% and a maximum of an order of magnitude difference. A similar comparison of power performance showed an approximate difference in the results of 10%. The LCoE calculation of the 10-WEC array system showed LCoE values that range from ?40% to +200% relative to the simulations that did not consider the hydrodynamic interaction effects. Comparatively, the LCoE calculation of the 2-WEC model either decreased by 17% or increased by 23% when the hydrodynamic interaction was included in the simulation model. ? 2020 Elsevier Ltd
Subjects
Continuum mechanics
Digital arithmetic
Fatigue damage
Hydrodynamics
Mooring
Wave energy conversion
Accumulated fatigue damage
Array configurations
Environmental loadings
Hydrodynamic interaction
Hydrodynamic interaction effects
Levelised cost of energies
Potential-flow theory
Wave energy converters
Mooring cables
array
fatigue
hydrodynamics
loading
mooring system
performance assessment
potential flow
structural response
wave energy
wave power
Type
journal article