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E-Thesis 299 views

Investigation and Optimisation of an Array-on-device configuration for a Novel Wave Energy Converter / EMILIO FARAGGIANA

Swansea University Author: EMILIO FARAGGIANA

  • E-Thesis – open access under embargo until: 20th February 2025

DOI (Published version): 10.23889/SUthesis.59692

Abstract

Wave energy has a huge potential to satisfy the global electricity demand from a renewable source. Many Wave Energy Converters (WECs) have been designed to harvest energy from sea waves but, to date, they cannot compete on the commercial energy market. However, the WaveSub, which is a point absorber...

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Published: Swansea 2020
Institution: Swansea University
Degree level: Doctoral
Degree name: Ph.D
Supervisor: Masters, Ian
URI: https://cronfa.swan.ac.uk/Record/cronfa59692
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Abstract: Wave energy has a huge potential to satisfy the global electricity demand from a renewable source. Many Wave Energy Converters (WECs) have been designed to harvest energy from sea waves but, to date, they cannot compete on the commercial energy market. However, the WaveSub, which is a point absorber developed by Marine power Systems Ltd, has a great potential to become one of the most promising future ways of wave energy extraction. This research project aims to develop and validate a numerical model of a multi-float configuration of the WaveSub device, followed by an optimisation of the design parameters to minimize the Levelized Cost Of Energy (LCOE). Hydrodynamic modelling of the device is based on a linear potential flow theory while a time domain simulation is used to estimate the power produced from the device. Then the drag force, the weakest point of the hydrodynamic forces calculation, has been investigated while the numerical model has been extended to include multi-directional waves. A benchmarking of the numerical model with tank testing of a 3 float WaveSub linear configuration against different regular wave cases demonstrated a good agreement with a relative mean total power difference between tank and model of around 10%. A genetic algorithm combined with the Kriging surrogate model was mainly used to optimise the LCOE. The 6 float configuration was found to operate at 21% lower LCOE compared to a single one. Finally, linear, rectangular, triangular and circular 6 float configurations were investigated. The circular configuration performed best with a LCOE reduction around 12% relative to the worst configuration. This work is a starting point for a more extended study of multi-float configurations, which can include more floats and complex geometries. Our results will help to develop a future multi-float WaveSub design, which can harvest renewable energy competitively.
College: Faculty of Science and Engineering