An analysis of the state-of-the-art development of wave energy converters (WEC) reveals that the majority of them are aimed at use in the open sea/oceans and are therefore poorly suited to the characteristics of wave movement in the Mediterranean. Furthermore, the devices developed have reached a maturity level of that does not yet allow industrial-scale production. The Italian coast (approximately 8,000 km) has coastal works that could be effectively used for wave power generation. The application of devices suitable for coastal use would result in savings in terms of installation, maintenance and connection costs to the electricity grid, and also avoid stringent environmental constraints regarding the laying of electrical transmission cables on the seabed. The WaveSAX device is a Oscillating Water Column Wave Energy Converter conceived and developed by RSE in previous years. The activities carried out have led to a progressive improvement in the performance of the device and a reduction in construction/maintenance costs, making it an interesting business opportunity for industrial operators.
The report describes the research activities aimed at optimizing the construction of the WaveSAX device, through numerical studies and experimental tests at sea on materials, operational configurations and control strategies. The computational fluid dynamics (CFD) study (code ANSYS-CFX v.16.0) aims at verifying the behavior of the device when the characteristics (height and period) of the incident wave movement vary. The experimental tests at sea of the WaveSAX device at 1:5 scale made it possible to identify the best control strategies to optimize the electrical production of the device and to evaluate the producibility in real wave movement conditions. Furthermore, it was possible to develop an updated power matrix according to the changes introduced to the device which led to a clear improvement in its conversion capacity (PTO). Finally, the analysis of currently available antifouling technologies and the results obtained from tests on materials at sea have made it possible to identify an antifouling protection strategy for the WaveSAX device, which can be implemented in the first full-scale prototype (1:1).