The Italian goals in the exploitation of wave energy
Pantelleria will be the first in Italy to exploit energy from wave motion for its electricity supply. The ISWEC device which since 2012 is located in Sicilian waters for studies and tests, was connected yesterday to the network of the island. A first national and world that has almost 20 years of commitment and that now enters a new phase. The small marine power station will not only contribute to the needs of the inhabitants but will serve as a demonstration base for the development of a second generation of machines for the exploitation of the sea.
What ISWEC is and how it works
The ISWEC, an acronym of Inertial Sea Wave Energy Converter, is a wave-motion energy converter. Compared to other devices made with the same purpose, it stands out thanks to the absence of fixed constraints on the seabed as well as components in relative motion in the water. The entire conversion unit is housed in a watertight environment within the floating body, to ensure minimal environmental impact. The heart of the car? A gyroscopic system consisting of two flywheels of 10 tons placed in rotation and installed in the sealed environment of the hull together with the electric generators. The device produces electrical energy through the coupling of the oscillatory movement of the hull and the rotary motion of the flywheels.
The strengths of the ISWEC are modularity (the gyroscopic unit can be changed to vary the rated power of the converter), reliability, competitiveness (the cost can compete with that of diesel power generation) and adaptability to different wave conditions (energy production is maximized thanks to a device control based on weather and marine data).
The project is signed by Eni, Politecnico di Torino and Wave for Energy s.r.l. – a spinoff of the university – and is one of the most advanced technologies Made in Italy for the exploitation of tidal energy. Behind years of studies and tests. The first concept dates back to 2006 but to arrive at the final release on a scale of 1:1 had to wait until 2012. In August of that year the three partners installed at 800 meters from the coast of Pantelleria and 35 meters deep, an ISWEC 8x15x4.5 meters, with a peak power of 260 kW.
Since then the consortium has studied performance and operation, waiting for the laying of the duct and the subsequent connection to the distribution network. But of Pantelleria is not the only Inertial Sea Wave Energy Converter, today in operation. Eni, Polito and Wave for Energy have realized a second pilot project with a nominal capacity of 50 kW, in the waters of Ravenna.
Energy from waves, potential
The sea is potentially the largest renewable energy source in the world. Recent estimates suggest that an available capacity of 2.7-3 TW is likely for world waters, corresponding to over 20 thousand TWh per year. In this macro sector the energy of the sea waves offers one of the most predictable and reliable renewable sources. It is continuous and has a higher energy density than wind and sun. Not only that.
As the three partners explain in a press release, ISWEC technology is characterized by a low landscape impact. “The device only emerges about 1 meter above the water level. Moreover, ISWEC can be perfectly integrated with other renewable energy production solutions in the offshore field, such as wind, in terms of both the enhancement of the systems of connection to the electricity grid and integration within a sea area, maximizing the conversion of available energy”.