Experimental Study of a Hybrid Wave Energy Converter Integrated in a Harbor Breakwater

Abstract

Sea ports are infrastructures with substantial energy demands and often responsible for air pollution and other environmental problems, which may be minimized by using renewable energy, namely electricity harvested from ocean waves. In this regard, a wide variety of concepts to harvest wave energy are available and some shoreline technologies are already in an advanced development phase. The SE@PORTS project aims to assess the suitability and viability of existing wave energy conversion technologies to be integrated in harbor breakwaters, in order to take advantage of their high exposure to ocean waves. This paper describes the experimental study carried out to assess the performance of a hybrid wave energy converter (WEC) integrated in the rubble-mound structure that was proposed for the extension of the North breakwater of the Port of Leixões, Portugal. The hybrid concept combines the overtopping and the oscillating water column principles and was tested on a geometric scale of 1/50. This paper is focused on the assessment of the effects of the hybrid WEC integration on the case-study breakwater, both in terms of its stability and functionality. The 2D physical model included the reproduction of the seabed bathymetry in front of the breakwater and the generation of a wide range of irregular sea states, including extreme wave conditions. The experimental results shown that the integration of the hybrid WEC in the breakwater does not worsens the stability of its toe berm blocks and reduces the magnitude of the overtopping events. The conclusions obtained are therefore favorable to the integration of this type of devices on harbor breakwaters.

Theoretical Analysis of a Vertical Cylindrical Floater in Front of an Orthogonal Breakwater

“…,m are the principal unknowns of the diffraction and radiation problems. In order to express the potentials in the form of Equations (13) and 14, Twerky's multiple scattering approach is implemented, taking into consideration the interaction phenomena between the floaters of the array. The method which is applicable to arrays consisting of an arbitrary number of vertical axisymmetric bodies, having any geometrical arrangement and individual body geometry, has been described exhaustively in previous publications [49,50]; thus, it is not further elaborated upon here.…”

“…Furthermore, breakwaters are typically considered as the most suitable and, subsequently, the most researched maritime structures for WEC integration. A number of reviews have been conducted regarding integrated WEC-breakwater systems [12][13][14][15].…”

A Numerical Assessment of Artificial Reef Pass Wave-Induced Currents as a Renewable Energy Source

“…The present study aims to propose a new perspective in the combined issues of nearshore protection and energy production [17,[19][20][21][22]. The guiding framework is to provide a novel insight on the development of artificial structures primarily designed as breakwaters, i.e., to shelter the coast from waves impact while accounting for ecological issues, but also, as a secondary requirement, to produce energy.…”

Performance Assessment of a Hybrid Wave Energy Converter Integrated into a Harbor Breakwater

“…The most challenging issues in the development of technologies for WEC-breakwater integration are:Energies 2020, 13, 236 3 of 22 WEC technologies considered were the sea-wave slot-cone generator (SSG) [16,24,25] and a shore based OWC [26,27]. It has also been established that the integration of the HWEC module into the breakwater does not significantly affect neither its effectiveness nor its stability [28,29]. Furthermore, the overtopping flow over the structure was considerably reduced by the integration of the HWEC module [8].The scope of this paper is to present the physical model study of the proposed HWEC module, at a 1:50 geometrical scale, to analyze the performance of the wave harnessing technologies and to discuss the differences and potential advantages of this hybrid device over its individual components.…”

“…Energies 2020, 13, 236 3 of 22 WEC technologies considered were the sea-wave slot-cone generator (SSG) [16,24,25] and a shore based OWC [26,27]. It has also been established that the integration of the HWEC module into the breakwater does not significantly affect neither its effectiveness nor its stability [28,29]. Furthermore, the overtopping flow over the structure was considerably reduced by the integration of the HWEC module [8].…”