Decarbonisation potential of hybrid fuel cell-battery systems in domestic ferry operations

This study investigates the environmental and regulatory impacts of replacing the diesel propulsion system of a domestic ferry with a hybrid system consisting of solid oxide fuel cells (SOFC) and batteries. Despite the high efficiency and low emission features of SOFCs, their limited capacity and slow start-up times restrict their use alone. These limitations are overcome by hybridisation with batteries, and the advantages of the two technologies are evaluated together. In the analysis conducted using operational data obtained from a 1065 deadweight tonnage (DWT) ferry and numerical simulations performed in the MATLAB Simulink environment, it is revealed that the hybrid system provides a reduction of 40% in carbon dioxide (CO₂) emissions and over 99% in sulphur oxides (SOx) and nitrogen oxides (NOx) emissions. In addition, the Energy Efficiency Existing Index (EEXI) is improved by 30%, ensuring compliance with the regulatory limits for 2030. On the other hand, it has been determined that the current diesel system will not be able to meet the EEXI requirements after 2024. The findings show that hybrid propulsion systems offer an effective solution for achieving the decarbonisation and sustainability goals in the maritime sector.