Fleet-scale evaluation of ammonia and hydrogen pathways under EU ETS and FuelEU Maritime regulations

This study assesses the environmental and economic potential of ammonia and hydrogen within the European Union's Emissions Trading System (EU ETS) and FuelEU Maritime regulations. Moving beyond case-specific studies, it analyzes verified 2023 monitoring data from 12,182 vessels operating in the European Economic Area across gray, blue, and green production pathways, using marine gas oil (MGO) as a benchmark. The assessment is conducted on a well-to-wake basis, with values for blue and green fuels obtained from GREET 2023 and MGO and gray fuels derived from FuelEU Maritime. Results show green ammonia and green hydrogen have the lowest greenhouse gas intensity, at 1.28 and 17.34 gCO₂eq/MJ. Carbon allowance costs are applied using a €90/tCO₂ baseline, and total cost is defined as fuel price, ETS and FuelEU penalty. Also, a Monte-Carlo uncertainty and Spearman-rank sensitivity analysis is performed to quantify the influence of key parameters (pilot-fuel share, carbon capture efficiency, ETS price, and fuel cost variability). While MGO remains cost-competitive until 2030, blue hydrogen emerges as a viable transitional choice around 2030. By 2040, model projections indicate that green hydrogen achieves the lowest total cost of ownership, while green ammonia attains the minimum lifecycle GHG intensity, positioning both as key compliance fuels under EU maritime regulations. The study concludes that green fuels are essential for long-term compliance and decarbonization, necessitating urgent investment in renewable production capacity and bunkering infrastructure.