# Comparative Analysis of Marine Alternative Fuels for Offshore Supply Vessels
## 4 Conclusions  
This paper conducted a comprehensive analysis of alternative fuels and propulsion technologies for offshore supply vessels (SOVs), focusing on LNG, hydrogen, ammonia, biofuels, and hybrid systems. Based on the findings, several key conclusions can be drawn:  
1. LNG as a Transitional Fuel: The analysis reveals that LNG provides the most feasible short- to medium-term solution for SOVs, with the potential to reduce greenhouse gas (GHG) emissions by approximately 20-25% compared to marine diesel oil (MDO) and heavy fuel oil (HFO). In addition to its lower carbon footprint, LNG infrastructure is relatively well developed, making it a viable near-term option for decarbonisation in the SOV sector.
2. Hydrogen and Ammonia for Long-term Decarbonisation: Hydrogen and ammonia have been identified as promising long-term alternatives, with the potential for zero-carbon emissions when produced using renewable energy. However, their widespread adoption faces significant challenges, particularly in terms of storage, handling safety, and the need for new infrastructure. For SOVs, hydrogen and ammonia could reduce CO\({}_{2}\) emissions by up to 100%, but only if these challenges are addressed.
3. Hybrid Propulsion Systems: The integration of hybrid propulsion systems, combining alternative fuels with electric or battery-based propulsion, was found to offer enhanced operational flexibility and fuel efficiency. In particular, hybrid systems could reduce fuel consumption by up to 15%, depending on operational profiles. Battery technology improvements also make full-electric operation increasingly viable for short-distance and low-power applications.
4. Infrastructure and Regulatory Needs: The adoption of hydrogen and ammonia for SOVs will require substantial investment in bunkering infrastructure and safety regulations. As such, these fuels are recommended as long-term solutions, while LNG and hybrid systems serve as more immediate alternatives for reducing emissions in the near future.  
In conclusion, this study underscores the importance of a phased approach to fuel transition in the SOV sector. LNG can offer immediate reductions in GHG emissions, while hydrogen, ammonia, and hybrid systems hold the potential to meet long-term decarbonisation goals, provided that technological and infrastructural barriers are addressed.  
Conceptualization, C.P. and B.J.; methodology, C.P. and B.J.; software, I.H. and H.J.; validation, S.H., J.K. and J.J.; formal analysis, I.H.; investigation, C.P., I.H. and H.J.; resources, B.J.; data curation, S.H. and J.J.; writing--original draft preparation, C.P. and H.J.; writing--review and editing, I.H. and B.J.; visualization, C.P. and H.J.; supervision, I.H. and B.J.; project administration, S.H. and J.K.; funding acquisition, J.J. All authors have read and agreed to the published version of the manuscript.  
This research was supported by Korea Institute of Marine Science & Technology Promotion (KIMST) funded by the Ministry of Oceans and Fisheries (RS-2023-00256331).  
Not applicable.  
The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding authors.  
The authors declare no conflict of interest.