Feasibility Study of the Decarbonisation and Electrification of a Commuter Ferry in Stockholm city

Sammanfattning: There is a need for alternative marine fuels and propulsion techniques in order to reduce the environmental and climate impacts of the transport sector, and meet the new Swedish climate targets of net zero emissions by 2045. There are several projects and studies on full electric ferries, while the option of hydrogen fuel cell-battery hybrids are not as well explored. This study assesses the prospects for three alternative fuels and propulsion techniques for a commuter ferry in Stockholm City. The fuels assessed are hydrogen (Fuel cellbattery hybrid/electric engine), electricity (Full battery/electric engine) and a biofuel (HVO/Internal combustion engine). Conventional diesel was included as benchmark. A multi-criteria decision analysis approach is employed in order to assess the fuel systems by estimated fuel performance and benchmarked input onthe relative criteria importance. The criteria cover economic, environmental, technical, and ultimately social aspects like availability and supply of fuel. The full battery solution was discarded due to excessive weight, but as only one charging solution was investigated it is recommended for further investigation. HVO performed best in an overall score comparing all fuel alternatives, but in a comparison between only fuel cell hybrid and HVO, including the availability criteria, the fuel cell hybrid system performed best. The analysis therefore supports the opportunity to implement fuel cell-battery hybrids onthis route.