Analysis of a supercapacitor/battery hybrid power system for a bulk carrier

Abstract

Concerns about harmful exhaust emissions from ships have been an issue. Specifically, the emissions at ports are the most serious. This paper introduces a hybrid power system that combines conventional diesel generators with two different energy storage systems (ESSs) (lithium-ion batteries (LIB) and supercapacitors (SC)) focused on port operations of ships. To verify the proposed system, a bulk carrier with four deck cranes is selected as a target ship, and each size (capacity) of LIB and SC is determined based on assumed power demands. The determined sizes are proven to be sufficient for a target ship through simulation results. Lastly, the proposed system is compared to a conventional one in terms of the environmental and economic aspects. The results show that the proposed system can reduce emissions (CO2, SOX, and NOx) substantially and has a short payback period, particularly for ships that have a long cargo handling time or visit many ports with a short-term sailing time. Therefore, the proposed system could be an eco-friendly and economical solution for bulk carriers for emission problems at ports.