With 7,500 kilometers of coastline, Italy stands to gain from any widespread deployment of wave energy. However, the coastline is often rugged, making it difficult to set up larger tidal tanks and sea-bottom infrastructure with cabling to the shore. Now a group of researchers funded in part by Enel Green Power has developed a smaller modular device that might be a solution for many areas.
Called the WaveSax, the device looks like, well, a big saxophone. Currently being developed and tested in artificial wave basins at one-fifth scale, the equipment generates electricity from air that is pushed up by waves entering the wider sax “horn” opening. The water coming up the pipe is referred to as an oscillating water column. The air then turns a small turbine, called a Wells Turbine, that generates power that can be transmitted to a storage site. The product was developed as part of a project by Italian firm RSE (Energy System Research).
WaveSax is especially designed for the typical wave climate of Mediterranean Sea, which has less wave action than the Atlantic ocean. The slim vertical nature of the WaveSax may allow it to be installed in tight areas including small rocky coves where there is significant wave action. The device has two essential characteristics, flexibility and replicability.
It can be installed using existing infrastructure and can be used repeatedly in the different climactic and physical conditions of the Italian coast. The slim vertical nature of the WaveSax may allow it to be installed in tight areas including small rocky coves where there is significant wave action.
The project began with the RSE team assessing advantages and disadvantages of the various systems and verifying their applicability for the Mediterranean. The team identified the Oscillating Water Column (OWC) configuration as the best suited for the region and its requirements.
The first step for this purpose was the execution of tests on a to-scale prototype of WaveSax, with the contribution of Enel’s Marine Energy Unit, which were recently concluded successfully in the in the ship model basin at the Cnr-Insean laboratory in Rome. Project development and testing were carried out through simulations and model tests in European ship model basins.
Based on preliminary results and the prospects of its application, Enel Green Power signed a collaboration agreement with RSE to assess the power take-off (PTO) of the device in real marine conditions with a concrete application on a 1:1 scale within a European project.
(Video below has Italian narration only)