The maritime shipping industry accounts for approximately 2-3% of global greenhouse gas emissions. The International Maritime Organization (IMO) has set a target to reduce Greenhouse Gas (GHG) emissions by at least 50% by 2050 compared to 2008 levels. The maritime sector faces unprecedented pressure to implement sustainable technologies while maintaining operational efficiency and economic viability. This current study presents a systematic review of advances in sustainable energy technologies for maritime decarbonization. The study scope covers alternative fuels, propulsion systems, energy- efficiency technologies, digital innovations, and policy mechanisms essential to achieving net- zero maritime operations. The review examines peer-reviewed literature and industry reports that synthesized evidence on technological maturity, environmental performance, economic feasibility, and implementation barriers across four technology categories. The four technology categories include: (1) alternative fuels, including LNG, methanol, ammonia, and hydrogen; (2) energy efficiency technologies encompassing hull optimization, waste heat recovery, and wind assistance; (3) electric and fuel cell propulsion systems; and (4) digital technologies. The study reveals that sustainable systems that incorporate digital technologies and AI-driven optimization enable an additional 3-5% in operational fuel savings. However, capital costs represent the dominant implementation barrier, with an investment of about 277-835 billion through 2050 across fuel infrastructure, vessel retrofits, and port electrification. The convergence of advancing technologies, declining renewable energy costs, and strengthening regulatory frameworks creates unprecedented opportunity for maritime decarbonization while maintaining the sector's essential role in global commerce.
Moses (Thu,) studied this question.