Hybrid hydrogen fuel cell and internal combustion engine powertrain arrangements for large maritime applications

Hydrogen as a maritime fuel can be used both in internal combustion engines (HyICE) and with fuel cells (FC). Batteries are required for FC to mediate load fluctuations and can be used with HyICE to reduce installed capacity at the cost of added mass and volume. This study compares the energy efficiency, mass and volume requirements for four hybrid configurations of hydrogen FCs, ICE, and batteries benchmarked against a direct drive diesel ICE. A 136.1 m long, 17.65 MW installed power, 1700 passenger ferry operating a 220 nautical mile liner service is chosen as a representative ship with a total voyage energy demand of 0.51 TJ. Such vessels are likely to provide a starting point in shipping fuel transition to zero carbon as mandated by the International Maritime Organisation. The comparative analysis uses recorded time-domain voyage power demand data and a matching time accurate Python model of the various power train configurations to provide a matching power supply. Results show that HyICE–battery systems achieve ∼49 % efficiency. The FC–battery hybrid has the highest efficiency (∼54 %). A triple hybrid of HyICE, FC, and batteries reduces battery capacity, mass, and volume by 72 % compared to FC–battery systems, without loss of efficiency. • Real-world ferry case study used to compare future powertrains fuelled with hydrogen. •Time-domain energy demand analysis enables a comparison of four different power system configurations. •Hydrogen combustion engines reduce battery size requirements (−72 %) in fuel cell–battery powertrains. •Hybrid hydrogen combustion engine–battery systems can achieve a total efficiency of up to 49 %. •Fuel cells offer higher efficiency for hydrogen utilisation but require greater space sacrifices.