Early Efficiency Estimation of Hybrid and Electric Propulsion Systems on Board Ships

This paper presents a methodology for evaluating different on-board power systems in the concept design phase. From an energy efficiency perspective, the potential advantages of a modern on-board power system are dependent on two major considerations: the design ratio between propulsion and auxiliary loads and the operational profile. These factors vary significantly for different ships and they can be roughly estimated very early in the design process, when only the main ship functions are known. An energy efficiency calculation method is proposed that has only these factors as input and is therefore applicable in the early stages of ship design.