Author(s): D. Vicinanza; P. Contestabile; E. Di Lauro

Linked Author(s):

Keywords: OBREC; Overtopping breakwater; Wave energy converter; Low-head turbines; Full-scale prototype

Abstract: The paper offers an overview of the last years of research work on a breakwater combined with an overtopping wave energy converter, denominated OBREC (Overtopping Breakwater for Energy Conversion). Recently, an original idea has been suggested to decrease the costs of the Wave Energy Converters (WECs) and at the same time to increase their reliability, consisting in integrating the devices into coastal defence structures such as rubble mound breakwaters or vertical caissons. Following this innovative attitude on the design of non-conventional coastal structures, a device denominated OBREC (Overtopping Breakwater for Energy Conversion) is under development. It is a breakwater with a peculiar shape designed to accommodate an OverTopping wave energy Device (OTD). The research team of the University of Campania “Luigi Vanvitelli” has developed the device and it consists of a concrete structure with a frontal sloping ramp and a reservoir located immediately behind it. The technology is able to capture part of the energy from incident waves that overtop the frontal ramp. The potential energy of the water stored in the reservoir is then converted into kinetic energy, flowing through low-head turbines located behind the reservoir. The energy is then converted into electrical energy by means generators coupled to the hydraulic turbines. After an extended preliminary physical model test carried out on the device in two complementary campaign in 2012 and 2014, a full-scale prototype has been installed in 2015 at the Port of Naples in Italy and it is in operation since 2016. The prototype represents the first non-conventional breakwater in the world, which exploits the overtopping phenomena in order to capture energy from waves and to convert it into electricity. It consists of a simple concrete structure with a frontal ramp and a reservoir situated behind it and located above the mean water level. The potential energy of the water stored in the reservoir is converted into kinetic energy and then into electricity by means of multi low-head turbines coupled with generators, placed in a machine room located behind the structure. Although the pilot is located in a site with a low energy potential, the present field monitoring of the OBREC is providing a more accurate comprehension of the structural and hydraulic performances without scale effects, as well as relevant information on the wave energy production for different wave conditions. In this reference, the prototype in Naples currently hosts three low-head fixed-Kaplan turbines with permanent magnet generator and maximum.

DOI: https://doi.org/10.3850/978-981-11-2731-1_095-cd

Year: 2018