Sustainable Marine Propulsion: A Review of Alternative Fuels and Propulsion Technologies

Abah MA, Oladetan JO, Oladosu MA, Agida OD and Amalagha GN

Published on: 2026-02-07

Abstract

Despite being the foundation of global trade, maritime transportation nevertheless makes a substantial contribution to air pollution and greenhouse gas emissions, which puts pressure on the industry to decarbonize. Due to international rules and the International Maritime Organization's stringent pollution reduction goals, conventional propulsion systems that use marine diesel and heavy fuel oil are no longer feasible. This review critically analyzes sustainable maritime propulsion methods by thoroughly analyzing alternative fuels and modern propulsion technologies.  By assessing their energy density, environmental performance, economic viability, safety implications, and infrastructure readiness, liquefied natural gas, hydrogen, ammonia, methanol, ethanol, biofuels, and synthetic e-fuels are being examined for their potential.  At the same time, propulsion advances including fuel cells, nuclear propulsion, battery-electric boats, hybrid electric systems, and wind-assisted designs are evaluated for their efficacy, technological sophistication, and utility. Technology and fuel synergies are highlighted in a comparative analysis, which acknowledges that transition plans would need adaptable, multi-fuel solutions.  In addition to innovation paths and policy motivators, barriers such as high costs, inadequate infrastructure, ambiguous rules, and public acceptance are also examined. The research concludes that industry, policymakers, and academia must collaborate to shift the maritime sector to low-carbon, sustainable, and eventually zero-emission propulsion, even if there is no one-size-fits-all answer. Tight restrictions, focused incentives, and ongoing research and development are required to support this endeavor.