Pathways to maritime decarbonisation: analysing alternative fuels across vessel classes

The maritime industry must transition to alternative fuels to ensure efficiency, safety, and sustainability. This paper addresses critical questions regarding the feasibility of alternative fuels in delivering net-zero carbon power. It evaluates the readiness of some of the most promising zero-carbon fuels and examines their integration with land-based infrastructure for shore power connections. The study analyses the adoption of alternative fuels across various ship types, including passenger and merchant vessels, while accounting for future fuel availability. A key component of this research is a custom-developed tool that dynamically simulates ship operations to evaluate energy demands and emissions on a semi-quantitative basis. The tool leverages detailed ship data, including class and dimensions, to establish onboard load profiles and propulsion demands. In addition, a Python-based algorithm was developed to define ship routes by retrieving real-time position data. The study focuses on alternative fuels such as LNG and methanol, including their bio and e-fuel variants, to assess their potential in decarbonising the maritime sector. Key performance indicators are used to measure the environmental and operational impacts of these fuels across different vessel classes. The findings provide strategic insights into the implementation of zero-carbon fuels in the short, medium, and long term, offering a roadmap for achieving decarbonisation targets. Results highlight LNG as a more favourable solution compared to methanol, owing to its higher energy density and economic competitiveness. Moreover, incentives plays a pivotal role in supporting transition, with an average required value decreasing from approximately 1172 €/t CO2 in 2023 to 81.8 €/t CO2 by 2040.