Obtaining energy from the waves of the sea: there is much talk about it but little is done, but now Enea (the national agency for new technologies and renewable energy) and the Polytechnic of Turin are taking a step forward: they have developed version 2.0 of the PEWEC, the converter of marine waves into electrical energy for the Mediterranean, where the waves are of small height and high frequency. This low-cost system of energy production from the sea is particularly interesting for the many small Italian islands that are not self-sufficient in terms of energy, where the supply of electricity is guaranteed by expensive and polluting diesel-fueled power stations.
The new floating system, similar to a semicircular hull to be positioned in the open sea, is able to produce electricity by exploiting the oscillation of the device due to the waves. Gianmaria Sannino, head of the ENEA Laboratory of Climate Modeling and Impacts explains: “PEWEC 2.0 presents some technological improvements compared to the previous version. A 1:25 scale prototype was tested at the Naval Tank of the Federico II University of Naples to study the response of the hull and moorings to extreme waves. We have exposed the hi-tech device to a series of particularly high waves (in scale), both regular and irregular, artificially generated inside the test basin, highlighting the system’s excellent holding capacity and electrical production even in extreme conditions. This type of tests are essential to evaluate the performance and resistance of the converters even in critical storm wave situations “.
ENEA and Politecnico di Torino are now working on the realization of the preliminary project of the PEWEC on a 1: 1 scale to be installed along the “most energetic” coasts of the Mediterranean, such as the west coast of Sardinia and the Strait of Sicily. The 525kW device will be 15 meters long, 23 meters wide and 7.5 meters high for a weight including ballast of over 1,000 tons. The team of researchers is also studying the cost reduction of the device and the increase of the energy transformation efficiency, through the adoption of low-cost materials and the integration of photovoltaic panels. This will ensure a reduction in the cost of energy, making the device competitive with other more mature renewable technologies.