SOFC powered cruise ships using future fuels: A comparison of cruising range

The global maritime industry needs to reduce CO 2 and pollutant emissions in order to comply with stringent emissions regulations and for climate change mitigation. Solid oxide fuel cells (SOFCs) are under consideration to be used as power plants for future ships. They offer advantages such as high efficiency, low emissions, fuel flexibility, and high-temperature heat output. However, their low power density brings concerns about their suitability for high-powered and space-constrained mobile applications such as cruise ships. This study addresses this concern by evaluating the cruising range that SOFC-powered cruise ships could attain when fuelled by a variety of future green fuels. Thermodynamic process models are developed for evaluating system performance. The size of each system component is calculated for estimating total space requirements. These SOFC systems are then optimised to maximise the cruising range of ships powered by them, while adhering to the volume constraints expected on cruise ships. Results show that SOFC cruise ships fuelled by green diesel or methane achieve a range of 4800–8600 nautical miles. Therefore, these ships could be used for ocean crossings. Most typical cruise itineraries are shorter, and can be fulfilled by almost all the fuels under consideration. Hydrogen-fuelled ships offer the shortest range — less than 1500 nautical miles. Irrespective of the choice of fuel, SOFCs attain high electrical efficiencies (44–65%) throughout their lifetime, and also satisfy a cruise ship’s heat demands. Therefore, this study suggests that SOFC-powered cruise ships are technologically feasible, motivating further economics- and logistics-based studies.