A new U-OWC device to produce electrical power from ocean waves: some applications to Italian coasts.

In the last decades, the research has directed its efforts and resources towards the possibility to incorporate wave energy converters, for the exploitation of wave energy, into the traditional maritime breakwaters to combine classical use with new opportunities and developments (for example, the Green Ports). Since the nineties, the OWC (Oscillating Water Column) plants were developed at full scale to produce electrical power from ocean waves. A prototype was built into a caisson breakwater of the Sakata Port, in Japan; other plants were built in Scotland at Islay, in Portugal at the Azores. A new plant was built in Mutriku (Spain) recently. A new kind of OWC caisson, named REWEC3 (Resonant Wave Energy Converter- Realization 3) or U-OWC, has been recently developed. The device has the quite desirable feature of working without the need of phase control systems. Further, it gives performances better than those of a conventional OWC either with small wind waves or with high waves. The REWEC3 properties have been verified with two small-scale field experiments carried out in the natural ocean engineering laboratory (NOEL) of Reggio Calabria off the eastern coast of the Straits of Messina. The paper disseminates the crucial characteristics of the U-OWC. Then, it proposes some results pertaining to the utilization of this plant at certain locations along the Italian coasts. Specifically, a UOWC plant will be supposed placed along the coasts of La Spezia, Ponza and Mazara del Vallo. The first location is representative of the North of Italy, the second one of the Centre of Italy and the third one is representative of the South of Italy. It is shown that the plant is capable of harvesting about 4500-7000 MWh/yr per 1km long plant.