Life cycle assessment of alternative marine fuels for super yacht

Abstract

Despite its relatively small size, the global super yacht fleet has considerable environmental impact. The emissions of these vessels, in concert with the wider maritime industry are under increasing scrutiny and pressure to achieve reductions. Ambitious policy targeting reductions in greenhouse gas (GHG), NOx and SOx emissions will require significant changes in vessel propulsion and fuel use. This paper examines the environmental impact of various alternative low-emission fuels for a super yacht. The study investigated well-to-wake energy consumption and the environmental impact of alternative low-emission fuels over the complete vessel lifetime. A comparative Life Cycle Assessment was performed on Marine Gas Oil (MGO), Liquefied Natural Gas (LNG), methanol, biodiesel and hydrogen with various energy production pathways. Results suggested that hydrogen produced using a wind energy pathway offers the most environmentally sound alternative to MGO; with a 93.95% reduction in GHG emissions and 91.95% acidification potential (AP) emissions. Fossil based alternatives have very limited potential to achieve regulatory reduction targets. Global warming potential (GWP) suggest that LNG fuel can reduce 20% to 25% CO2 emission in the Tank-to-Wake phase in comparison with MGO. However, considering CH4 emissions, may result in a 5.4% higher GWP. The results highlight the differences in lifecycle emissions as a result of different production pathways. The paper concludes with recommendations for hydrogen from a renewable production.