Evaluation of a hybrid SOFC & battery genset for cruise ship applications

Abstract

As the maritime transport industry accounts for a significant part of the global greenhouse gases and emissions, the International Maritime Organization (IMO) is aiming at a 40 % reduction of CO2 by 2030 and 70 % by 2050. In addition, SOx, NOx and, black carbon emissions shall be decreased by 80 % in comparison to 2008. In order to achieve these goals, solid oxide fuel cells are estimated to play a major role in power generation onboard, due to their high fuel efficiency, flexibility, and very low emissions. In order to improve their load change behavior, they can be coupled with batteries to allow for high power gradients that are characteristic for ship operation. In this contribution, the current status of an experimental proof of concept (PoC) in conjunction with transient simulations, funded within the European project NAUTILUS, will be shown. The PoC uses a 32 kWe SOFC module, coupled with a lithium-ion battery. It represents a conceptional genset that is evaluated to gradually replace conventional gensets on cruise ships, considering its transient behavior and scalability. The genset concept and its influence on the main key performance indicators for the targeted maritime application will be presented. Furthermore, first simulations of its load-following behavior and control concept will be shown. First simulations of the transient behavior of the used SOFC module will be presented. The evaluation shows that such a genset has the potential to meet the technical requirements onboard, that the transient behavior via hybridization with a battery can be improved and that it is a viable alternative for conventional gensets on ships considering its higher efficiency and lower emissions. It also shows that the battery will mainly be used in the transition phases during startup of the gensets while its usage in peak shaving during steady state operation is restricted by the suitable battery volume on ships.