Fuel Saving Effect of Hybrid Propulsion System - Case: Tugboat is on Service

Abstract

Tugboats are rarely required to produce great propulsion power even while they are “On Service’. In this paper, the authors compared SFC (specific fuel consumption) for a hybrid propulsion system with that for a conventional propulsion system while they are on service. SFC was calculated by using a method developed by the authors. The fuel consumption characteristics of the hybrid propulsion system were measured against those of the conventional propulsion system that included the main engine and the diesel generator. The results showed that the hybrid propulsion system has higher SFC than the conventional one, highlighting the possibility that the former can, lead to increased fuel consumption. This indicated how diesel generators being forced to operate at low loads have an impact on fuel consumption. Furthermore, this also indicated the importance of designing ratings of motor generators appropriately in hybrid propulsion system.