ABSTRACT
A plug-in hybrid propulsion system comprising of a Proton Exchange Membrane Fuel Cell (PEMFC) and lithium battery capable of being recharged in port offers a promising low carbon propulsion system for small coastal ships, e.g. small container ships, tankers and ferries, which typically sail over short routes at modest speeds. PEMFC operate at high efficiency and emit no harmful emissions, but their poor transient performance necessitates the need for an energy storage system such as a lithium battery. A shore-to-ship electrical connection is needed to recharge the lithium battery from the grid so as to improve the propulsion system performance both environmentally and economically. Production of both H2 and grid electricity have a carbon footprint. In this paper a two-layer optimisation based methodology is used for the design of plug-in hybrid fuel cell and lithium battery propulsion systems for coastal ships. Results from a case study suggest that the design of hybrid PEMFC and battery propulsion systems should be influenced by the ‘well-to-propeller’ carbon footprint.
