Evaluating the techno-economic feasibility and social impact of methanol as a marine fuel

Alternative marine fuels are indispensable to the decarbonisation of shipping. This study evaluates the techno-economic feasibility and wider societal effects of methanol, sourced from fossil gas, biomass residues and renewable hydrogen/carbon dioxide, relative to very low sulphur fuel oil (VLSFO). A well-to-propeller life-cycle assessment is combined with the life cycle costing model for a container vessel. Fossil methanol raises life-cycle greenhouse-gas (GHG) emissions by 8.7 % versus VLSFO, whereas bio-methanol and e-methanol lower GHGs by 47 %–81 %, depending on feedstock and carbon source. All methanol pathways reduce combustion-phase emissions by 11.9 %, translating into 6 %–73 % lower health damage and up to 90 % lower resource depletion costs. Economically, methanol's cost-competitiveness remains challenged primarily due to higher capital expenditures and fuel price volatility. However, incorporating social impacts by monetising environmental externalities significantly enhances methanol's comparative attractiveness, demonstrating lower societal costs in 86 % of scenarios according to Monte Carlo uncertainty analysis. The findings underscore the necessity of targeted policy interventions, such as production incentives, capital expenditures subsidies, and effective carbon pricing mechanisms, to unlock the environmental and social benefits of renewable methanol pathways. The outcomes provide robust, evidence-based guidance for regulatory and industry strategies towards the International Maritime Organization's 2040 and 2050 decarbonisation ambitions.