The Italian National Agency for New Energy Technologies (ENEA) in collaboration with the Polytechnic University of Turin recently presented its new smart and low-cost tool that produces electric energy from sea waves.


The potential of the PEWEC (Pendulum Wave Enegy Converter) has been unveiled during the conference “Electric Energy from the Sea”: “Ten of these devices can produce enough electricity to power 3,000 households”, declared Gianmaria Sannino, director of ENEA Energy and Environment Modelling Technical Unit. Moreover, “the Italian islands, powered by expensive and polluting diesel plants, are the ideal candidates for this new technology”. This device also reduces coastal erosion by depowering the force of the waves crashing against the coast, reducing impacts flora and fauna.


The advantages of this technology: According to ENEA, PEWEC has a low environmental and visual impact (which can make this technology more attractive than solar and wind energy production), a low daily variability and a favourable season variation (wave energy potential is higher in winter, when energy consumption is at its maximum).


How does it work? The PEWEC (whose 1:12 prototype can be already seen at ENEA headquarters in Rome) is a floating, raft-resembling device, to be position offshore that relies on the hull oscillation induced by waves. It has been modelled specifically for the Italian coast waves which present the characteristics of small size, mild intensity and high frequency.


The strength of this innovative device is the simplicity. "It is a hull, like an eggshell with a pendulum to Internal that oscillates,” Sannino said. “The relative motion between the hull and pendulum generates electricity because the pendulum is tied to a power generator.” Simplicity is the key: given its basic mechanism, this smart device is able to capture every kind of wave and produce electricity in an efficient and low-cost way.


Where can it be used? In Italy we observe a growing interest in the production of green energy from sea waves. With over 8,000 km of coastline Italy has a great potential, comparable to the East Cost of the North Sea. To give you an idea of the magnitude:  Sardinia North West average offshore wave power is 13 kW/metre and Sicily North West is 10 kW/metre.


Is it already in action? No. Only the prototype 1:12 has been produced. Currently, the ENEA team with the collaboration of the Polytechnic University of Turin is working on the next step: producing a prototype 1:1, with a 400 kw nominal power. It will probably take one year/one year and a half.


A comprehensive and forward-looking approach. ENEA has presented a “Mediterranean Wave Energy Atlas”: a map of the areas presenting the best characteristics for sea energy production, with detailed data on speed of currents, height of waves, and the intensity of tides. ENEA is also participating in the joint research program on the energy from the sea “JP Marine Renewable Energy” as proposed by the European Agency Research Alliance.


In addition, ENEA has developed an operating system for the sea state prediction up to 5 days, being able to estimate the quantity of energy to feed into the electrical grid to an accuracy of a few metres.


Eliana Canavesio