Development of a composite sea wall wave energy converter system

The cost-effective utilization of wave energy is still a major engineering challenge. Shoreline locations for Wave Energy Converters (WECs) offer lower wave energy densities when compared with offshore locations, but give significant advantages from the points of view of construction, maintenance and grid connection. This article provides a first analysis on the viability of a very low-head hydropower plant, in which waves accumulate water into a shoreline reservoir created by a steep detached ramp. The system is particularly suitable for micro-tidal environments such as the Mediterranean Sea and has the additional advantage of protecting shorelines, seawalls and coastal assets from wave action. Physical model tests, conducted with regular waves, have been used to get a preliminary estimate of the average water flux overtopping the ramp in a sea state; a novel low-head hydropower machine, developed at Southampton University, has been considered for the conversion of the hydraulic energy into electricity. The site of Porto Alabe, located along the West coast of Sardinia (Italy), has been chosen as a first case study. Based on the inshore wave climate, the layout of the ramp has been designed as a tradeoff between the needs of maximizing the energy production, providing the coastal area with an adequate protection and making the plant a desirable investment to either private or public players. The results are interesting both from a technical and an economic point of views and encourage a further deepening on the response of this kind of WEC

Nature and magnitude of wave loadings at Seawave Slot-cone Generators

The Seawave Slot-cone Generator (SSG) is a wave energy converter based on the overtopping principle,which has collected a good deal of funds in the last years, from both public and private investors.Although its functional response has been extensively researched, practically no tools exist for thestructural design. Based on the results of regular wave experiments conducted at the University ofNaplesFederico II(Italy), a number of design equations have been derived, which permit to estimate themagnitude of the wave pressures acting onto the outer face of the device, along with the respective risetimes. The reliability of the predictive methods have been then verified against the random waveexperiments ofVicinanza and Frigaard (2009)

Wave Pressures and Loads on a Small Scale Model of the Svåheia SSG Pilot Project

The paper reports on 2D small scale experiments conducted to investigate wave loadings acting on a pilot project of device for the conversion of wave energy into electricity. The conversion concept is based on the overtopping principle and the structure is worldwide known with the acronym SSG. The hydraulic model tests have been carried out at the LInC laboratory of the University of Naples Federico II using random waves. Results indicate wave overtopping is able to cause a sudden inversion of vertical force under wave crest, so that it is alternatively upward and downward directed over a short time interval. It is also shown that two calculation methods widely employed in the Japanese design practice of vertical face breakwaters, could be used to achieve safe estimates of the hydrodynamic loadings

Non Breaking Wave Forces at the Front Face of Seawave Slotcone Generators

The Seawave Slotcone Generator (WAVEnergy SAS, 2003) is a wave energy converter based on the overtopping principle. Although it has been effectively researched during the last decade, no design tool has been supplied to estimate the hydrodynamic loads the waves exert on its front face. In this article a set of well reliable 3D experiments has been re-analyzed, in order to get indications on possible calculation methods. It is shown that the Japanese design tools for monolithic sea dikes may be reasonably adapted to the present case. Finally a new approach is presented, which is based on the so called momentum flux principle; the resulting predictive equation fits the experimental data remarkably well

Conceptual approach for prediction of wave transmission at low crested breakwaters

Although detached, low-crested breakwaters are frequently employed for beach stabilization, no design tool is available nowadays that reliably predicts the transmissivity of these structures for a wide range of engineering conditions. With this in view, the paper presents a semiempirical model where the predictive equations have been obtained starting from a crude schematization of the physical processes that govern wave transmission. The obtained results are encouraging and show good agreement with a large ensemble of experimental data

Conceptual approach for prediction of wave transmission at low crested breakwaters

Although detached, low-crested breakwaters are frequently employed for beach stabilization, no design tool is available nowadays that reliably predicts the transmissivity of these structures for a wide range of engineering conditions. With this in view, the paper presents a semiempirical model where the predictive equations have been obtained starting from a crude schematization of the physical processes that govern wave transmission. The obtained results are encouraging and show good agreement with a large ensemble of experimental data

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A semiempirical approach for wave transmission at low crested breakwaters.

Il lavoro propone un modello per il calcolo della trasmissione ondosa a tergo di opere a gettata a cresta bassa o sommerse. Il modello è fisicamente basato ed è stato validato con un ampio insieme di dati sperimentali