Modeling of a Point Absorber for Energy Conversion in Italian Seas

TLDR

Clean electric power production from ocean waves in the Italian seas is a promising but still unconfirmed prospect. The study investigates the feasibility of generating electricity from waves in Italian seas using the Seabased wave energy converter. A numerical model of the coupled buoy–generator system, based on linear potential wave theory and an analytical generator model, is used to simulate two buoy sizes and a submerged resonant object, and to estimate energy production at eight Italian offshore sites. Simulations agree with published data and show device utilization above 20 % at Alghero and Mazara del Vallo, rising above 40 % at most sites when a submerged resonant object is added, with the highest value at Mazara del Vallo.

Abstract

In the present paper, we investigate the feasibility of wave electricity production in Italian seas by the deployment of the Seabased wave energy converter (WEC). A numerical model of the coupled buoy-generator system is presented, which simulates the behavior of the wave energy converter under regular waves of different wave heights and periods. The hydrodynamic forces, including excitation force, radiation impedance and hydrostatic force, are calculated by linear potential wave theory, and an analytical model is used for the linear generator. Two buoys of different radii are considered to explore the effect of buoy dimension on energy conversion and device efficiency. The power output is maximized by adding a submerged object to the floating buoy, in order to bring the system into resonance with the typical wave frequencies of the sites. The simulation results show a very good agreement with the published data on the Seabased WEC. The model is used to estimate energy production at eight Italian offshore locations. The results indicate that the degree of utilization of the device is higher than 20% at the two most energetic Italian sites (Alghero and Mazara del Vallo) and that it can be considerably increased if the floating body is connected to a submerged object, thanks to the resonant behavior of the WEC. In this case, the degree of utilization of the device would be higher than 40% at most of the study sites, with the highest value at Mazara del Vallo. The work enlarges the perspective, to be confirmed by experimental tests and more accurate numerical modeling, on clean electric power production from ocean waves in the Italian seas.