A comparative modelling approach to environmental-economic trade-offs of low-carbon fuels in coastal shipping

Abstract The article presents an interdisciplinary study examining the environmental and economic implications of introducing low-carbon fuels in coastal shipping. The main focus is on the comparison of alternative energy sources - from biofuels and methanol to ammonia and hydrogen - by the criteria of emissions, cost, technical readiness and logistical feasibility. A comprehensive assessment model is proposed that integrates life cycle parameters, marginal abatement cost (MAC) and strategic implementation scenarios until 2050. Particular attention is paid to a hybrid gradual transition scenario that combines early biofuels with a long-term transition to hydrogen and ammonia. The presented results serve as a practical tool for developing decarbonization roadmaps and decision-making in the transport and port sectors. The work has practical implications for public policy, shipowners and investors in the context of the energy transition and climate commitments. The results showed that switching from HFO to Bio-LNG or green methanol reduces CO₂ and SOx emissions, while increasing total operating costs.