To advance wave energy devices towards commercialization, it is essential to optimize their design to enhance system performance. Additionally, a thorough economic evaluation is crucial for making these technologies competitive with other renewable energy sources. This study focuses on the techno-economic optimization of an innovative inertial system, the so-called SWINGO system, which is based on gyropendulum technology. SWINGO stands out due to its high energy efficiency in multi-directional installation sites, where wave directions vary significantly throughout the year. The study introduces the application of a multi-objective Evolutionary Algorithm (EA), specifically the Non-dominated Sorting Genetic Algorithm II (NSGA-II), to optimize the techno-economic performance of the SWINGO system. This approach aims to identify optimal design parameters that maximize energy extraction while considering economic viability. By deriving a Pareto frontier, a set of optimal devices is selected for further analysis. The performance of the SWINGO system is also compared to an alternative (mono-directional) inertial wave energy converter, the Inertial Sea Wave Energy Converter (ISWEC), to highlight the differences in techno-economic outcomes. Both systems are evaluated at two different installation sites: Pantelleria island and the North Sea in Denmark, with a focus on the directional wave scatter at each location.

Offshore wind is central to decarbonisation, yet its deployment in the Mediterranean Sea is increasingly constrained by grid limitations and curtailment. This study presents a geospatial techno-economic competitiveness assessment of offshore wind and hybrid offshore wind-hydrogen systems across the Mediterranean basin. Results show that optimal grid-connected offshore wind configurations achieve a LCOE of 48.4/MWh, while hybrid Power-to-X configurations reach a minimum LCOH (expressed in energy-equivalent terms) of 81.4/MWh. Under favorable market conditions, hybrid systems can achieve positive net present values, with a minimum payback time of 11 years, highlighting a strong dependence of economic performance on price scenarios. Power-to-X solutions, in particular hybrid wind-hydrogen systems that convert part of the offshore wind output via electrolysis, offer an alternative route to valorize offshore wind beyond direct grid injection. The analysis evaluates hybrid configurations in which 10%–90% of the wind farm capacity is allocated to on-site hydrogen production, compared against a conventional electricity-to-grid baseline. The assessment spans diverse Mediterranean locations and adopts the levelised cost of hydrogen as the main performance indicator to compare hybrid and stand-alone electricity-export setups, alongside complementary economic metrics. Results indicate that, when considering pure cost minimization, the grid-only scenario systematically delivers the lowest levelised cost across all assessed locations. However, sensitivity analysis to electricity and hydrogen market prices shows that hybrid configurations can become economically attractive under moderate-to-favorable conditions, despite higher levelised costs. Overall, the findings demonstrate that while offshore wind-hydrogen systems are not cost-optimal under current baseline assumptions, they may represent a viable future strategy to unlock offshore renewable potential in regions facing grid integration constraints and to support long-term hydrogen market development and decarbonisation objectives in the Mediterranean context.

Offshore wind and green hydrogen are expected to play a central role in Mediterranean decarbonisation, yet deep waters, intense coastal uses, and visual-acceptance constraints make siting and system design challenging. This study develops an integrated geospatial and techno-economic framework that combines marine spatial-planning layers, long- term wind reanalysis, offshore wind-farm design, and power-to-x valuation to assess where offshore wind can support electricity supply and hydrogen production. Spatial exclusions, bathymetric limits, and a visual-impact index reduce the basin to about 2.05 · 106 km2 of eligible sea space (about 24% of the Mediterranean). For each grid cell, multi-year wind series are coupled with precomputed performance and cost tables for fixed-bottom and floating concepts, multiple turbine ratings, layouts, and spacings, producing spatially resolved indicators for annual electricity yield and levelised costs for electricity and hydrogen. For Italy, Greece, and Cyprus, 2030 electricity and hydrogen targets can be met using less than 8% of the eligible area, while export-oriented 2050 cases require up to about 55% in Italy and 75% in Greece and Cyprus, with avoided emissions on the order of several tens of MtCO2 yr−1.