Wave Energy Converter Feasibility in Türkiye’s Surrounding Waters: A Twenty-Year, Four-Basin Assessment

Wave energy in short-fetch, semi-enclosed seas depends on how closely the response of a converter matches locally generated, short-period waves. This study makes that match explicit for the Black Sea, the Sea of Marmara, the Aegean, and the Eastern Mediterranean, the four seas around Türkiye, as four distinct regions within a single study area. Twenty years (May 2006 to March 2026) of three-hourly significant wave height and energy period from the Copernicus Marine global wave reanalysis (0.2°) were combined with GEBCO 2026 bathymetry to map the wave power flux, to screen cells inside a first-order 25–100 m deployment-depth band, and to rank three candidate sites in each region. Specific power matrices were applied to three full-scale reference converters (Pelamis P-750, AquaBuOY and Wave Dragon) and to two shallow-water archetypes, the Oyster surge flap and the Wavestar multi-float machine, standing for contemporary shallow-water design classes, at full scale and under Froude similitude. The best deployable sites of the Black Sea and the Aegean carry mean fluxes of 3.1–3.6 kW m−1, and the Marmara sites define the low-resource end member at 0.2–0.8 kW m−1; mean energy periods at the twelve sites range from 2.7 to 5.4 s. At their original scale the three reference converters reach capacity factors of up to 3.4%, because their specific power matrix response bands fall largely outside the regional sea-state distribution. Scaling changes that. Froude scaling to 0.20–0.25 of the original linear dimensions moves the response into the dominant 4–5 s band and raises the capacity factor to 30–47% at the seven sites where the mean flux exceeds 2.5 kW m−1, at scaled rated powers of about 2–25 kW; the two archetypes reach 7–19% at full scale and 49–59% once scaled at the same sites. Both the preferred scale and the achievable capacity factor are near-uniform along the Black Sea rim, the Aegean archipelago, and the Levantine shore, so the analysis yields a single regional design specification, as follows: a small, short-period converter deployed in modular arrays.