Italian National Agency for New Technologies, Energy and Sustainable Economic Development
Energy: ENEA-poliTO device to generate energy from waves starts trials
A system which could potentially supply small Italian islands not energy self-sufficient
ENEA and Polytechnic University of Turin have developed a 2.0 version of PEWEC[1], a wave energy converter for the Mediterranean, where the waves are of small height and high frequency. This low-cost device to harness wave energy could be useful to the many small Italian islands which are not energy self-sufficient and where electricity is supplied by expensive and polluting diesel powered generators.
The new floating system, similar to a semicircular hull to be positioned in the open sea, can generate electricity by exploiting the oscillation of the device caused by the action of the waves. “PEWEC 2.0 features some technological improvements over its predecessor. A 1:25 scale prototype was tested at the Vasca Navale of the Federico II University of Naples to study how the hull and moorings would react to extreme wave conditions.
We exposed the device to particularly high waves, both regular and irregular, artificially generated within the test basin, highlighting an excellent holding capacity and electrical production of the system even in extreme conditions. This type of tests are crucial to assess the performance and resistance of the converters even in extreme conditions ”, explained Gianmaria Sannino, head of the ENEA Laboratory of Climate Modeling and Impacts.
ENEA and Poytechnic University of Turin are working on a preliminary project of the PEWEC on a 1: 1 scale, to be installed along the Mediterranean coasts with the highest energy potential, like 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 with a weight of over 1,000 tons.
The Research team is also studying to reduce the costs of the device and increase the energy transformation efficiency by adopting low-cost materials and integrating photovoltaic panels. This is expected to reduce the energy cost, making the device competitive against more mature renewable technologies [2].
“The Turin Polytechnic Lab team has developed advanced numerical codes to develop the technology and assess the manufacturability of the device. Genetic optimization codes, based on the Darwinian concept of natural selection, were adopted to reduce its energy cost. The experimental tests conducted at the Naples Naval Basin were crucial in demonstrating and validating the promising numerical results obtained”, said Giuliana Mattiazzo at the Turin Polytechnic, head of the MOREnergy Lab research center (Marine Offshore Renewable Energy Lab).
"The estimated market potential in the Mediterranean basin can be calculated based on these data: our contry has over 50 smaller islands with an average population of approximately 2500 inhabitants, an average per capita consumption of 6 kWh / g and a very high energy cost. A dozen of these devices could produce electricity to power a village of 3 thousand inhabitants, considerably contributing to counteract pollution and erosion by reducing the energy of the waves that break on the coast, without a significant impact on marine flora and fauna ”, said Sannino.
The PEWEC can fully satisfy the energy needs of small and medium-sized islands that base their energy supply on fossil fuel plants. These technologies can be implemented for domestic, civil and industrial use (for example in aquaculture). Electricity in aquaculture plants is increasingly used for food distribution, water recirculation / oxygenation, lighting.
The cost of electricity associated with diesel in aquaculture was estimated in 2018 at 0.4-0.6 € / kWh, equal to 19% - 45% of wholesale fish price. The impact of a system like PEWEC allows an on-site eco friendly energy generation in a green fish farming perspective.
The "Working Group Ocean Energy" of the SET Plan, chaired by ENEA since 2021, has developed a roadmap with two long-term goals: the objective in 2025 is the development of operational devices that have passed the technical and financial demonstration phase; in 2030 to achieve a large-scale installation phase almost at commercial costs.
The 'SET Plan Ocean Energy Implementation Plan' also provides an estimate of the investments needed to advance Europe's leading position on energy from the sea and strengthen Europe's industrial technology base, thus boosting economic growth and creating new jobs: 1 billion euro between 2021 and 2025, of which 33% from private funds, 40% from regional and national programs, the remaining 27% from European funds for innovation. According to data from the second OceanSET report, in 2019 in Europe energy from the sea received 42.7 million euro funding from regional and national research and development programs.
The United Kingdom allocated the highest budget for Ocean Energy with 22 million euro, while France ranked second with 5.8 million euro. Italy, Spain, Sweden and Ireland were
between € 2 million and € 4.7 million; the least allocation was by Germany with 1 million euro. The Netherlands, Belgium, Denmark, Finland, Norway and Cyprus had no budget in 2019 for energy from the sea. “To be in line with the EU objectives, it would be necessary to double the overall budget of the Member States in this sector”, Sannino pointed out.
At a technological level, 127 sea energy projects are funded, of which almost 60% concern wave energy devices; 25 have a TRL 7 or a higher level of technological maturity, therefore almost ready for market implementation.
The European Union plans to deploy 100GW of production capacity by 2050, meeting 10% of electricity demand. That’s enough to meet the daily electricity needs of 94 million households, with significant environmental benefits (234 million tons of CO2 avoided), on energy dependence of the EU (with a 266 billion euro cut on the European 'bill') and on employment, with at least 500 thousand new jobs.
Italy has a technology cluster called BIG (Blue Italian Growth) which aims at systematizing the many Italian skills in the offshore sectors; specifically, one target is focused on marine renewable energies, with a collaborative workshop to be held in Rome on 24-25 February for an update of the national action plan, to favor the achievement of the EU objectives on sea energy.
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