Comparative Life Cycle Assessment of electric hydrofoil boats and fossil driven alternatives

Abstract: The pressure on the planet from Global Warming mainly originates from human activity since the Industrial Revolution. If the average temperature would increase by 1.5 degrees compared to pre- industrial level, this could highly affect areas such as biodiversity, food availability and water levels, to just name a few. In 2020, the transportation sector was responsible for 24 % of the emissions on a global scale. To mitigate climate impacts from transportation, the electrification of cars has already come a long way, but in the boating sector, more needs to be done. There is a lack of studies of comparative life cycle assessments about electric and fossil driven boats.  Two studies are conducted in this thesis. The first study focuses on the difference in environmental impact between an electric hydrofoil leisure boat and two petrol driven alternatives. In the second study, the ferry Candela P-12 is compared to the current diesel driven ferries used on Ekerölinjen in Stockholm. The method that is used to determine the environmental impact of the different boats, is a comparative Life Cycle Assessment (LCA). Three impact categories are assessed in the analysis of the environmental impacts. Global Warming Potential (GWP) to calculate the CO2-eq. emissions, Mineral Resource Scarcity (MRS) to account for scarce minerals that are commonly used in electric vehicles and therefore lead to a high impact in this category, and Cumulative Energy Demand (CED) to evaluate the total energy consumption by the vehicles.  The result from the leisure boat comparison shows that the C-8 is highly favorable in two out of three impact categories, namely GWP and CED. Only in relation to MRS, the C-8 has the highest impact, mainly due to manufacturing in general, and specifically the batteries. The total life cycle impact of the Candela C-8 concerning GWP is affected by different grid mixes. However, compared to the emissions from the combustion engines, the differences in the grid mixes become small.  In the second study, the result showed that utilizing three Candela P-12 ́s to fulfill the function of Ekerölinjen will mitigate the environmental impact in GWP by 1670 tons for CO2-eq per year. It can be concluded that the P-12 is more environmentally friendly in all three impact categories in comparison to the current ferries on Ekerölinjen if the occupancy rate is considered.