Wave energy converters in array configurations—Influence of interaction effects on the power performance and fatigue of mooring lines
2020 (English)In: Ocean Engineering, ISSN 0029-8018, E-ISSN 1873-5258, Vol. 211, article id 107294Article in journal (Refereed) Published
Abstract [en]
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.
Place, publisher, year, edition, pages
Elsevier Ltd , 2020. Vol. 211, article id 107294
Keywords [en]
Fatigue analysis, Interaction effect, Levelised cost of energy, Mooring system, Power absorption, Wave energy converter
National Category
Engineering and Technology
Identifiers
URN: urn:nbn:se:ri:diva-45372DOI: 10.1016/j.oceaneng.2020.107294Scopus ID: 2-s2.0-85087285271OAI: oai:DiVA.org:ri-45372DiVA, id: diva2:1455179
Note
Funding details: Energimyndigheten; Funding text 1: The authors gratefully acknowledge the financial support provided by the Swedish Energy Agency for the project entitled “Simulation model for operation and maintenance strategy of floating wave energy converters – analysis of fatigue, wear, and influence of biofouling for effective and profitable energy harvesting” through Contract No. P36357-2. We also thank the Swedish company Waves4Power ( https://www.waves4power.com/ ) for providing the WEC system configuration and information about the Runde test site. Professor Lars Bergdahl at Chalmers University of Technology is acknowledged for the valuable advice and discussions.
2020-07-222020-07-222021-01-13Bibliographically approved