Vol 77 No 4 77412

Growing environmental awareness and increasingly stringent emission limits are key drivers in modern ship design. Alongside innovations in energy conversion systems, overall ship sustainability depends on optimizing electrical systems, propulsion efficiency, and operational profiles while integrating alternative fuels. This study examines the energy costs and emission performance of a cruise ship operating in the Adriatic Sea over a 25-year horizon (2025-2050), comparing three fuel options: High Sulphur Fuel Oil, Liquefied Natural Gas, and Methanol. The analysis includes Well-to-Wake emissions, compliance costs related to the EU Emissions Trading System and FuelEU Maritime, and the evolution of the Carbon Intensity Indicator. In terms of Well-to-Wake emissions, e-Methanol achieves the lowest Green House Gasses intensity, while Natural Gas-based Methanol exceeds High Sulphur Fuel Oil due to upstream contributions. Only bio- and e-Methanol maintain Carbon Intensity Indicator compliance over the full 25-year horizon. Cost-wise, e-Methanol becomes the most competitive option by 2040, driven by avoided FuelEU penalties. The findings highlight the need for an integrated approach combining technological innovation, efficient energy management, and regulatory adaptation toward sustainable cruise operations.