Liquid hydrogen as a potential decarbonization solution for a large cruise ship

Abstract

An increase in customer demand for cruising is prompting major industry players to allocate considerable resources to the construction of new ships that are energy efficient and environmentally compliant. This study examines the energy transition possibilities by retrofitting a large cruise ship and develops a procedure to evaluate the suitability of liquid hydrogen as a potential decarbonization solution. The utilized approach in this paper includes technical and safety assessment of the possible energy system options with liquid hydrogen as fuel, to identify the optimal solution. The technical assessment evaluates the required volume and weight of each system option using vessel particulars and operational data. The energy system sizing is based on available technology data in the market, and the sizing of fuel storage system is based on a sample liquid hydrogen containment system and its adaptability onboard. Additionally, a safety assessment of hydrogen storage and each energy system option is conducted, analysing the applicability onboard, with a focus on the frequency of hazardous events. This approach can be transferred to other ship types and further developed to compare other alternative fuels. Furthermore, it can be improved by incorporating economic and regulatory assessments. The results of a sample case study with installed 40 MW power onboard, indicate that decarbonization of cruise ships using liquid hydrogen is possible. Among studied scenarios, a system with 40 MW PEMFCs and 10 MW batteries is suggested as an optimum solution. This system, despite requiring 1.87 more volume, represents only 35% of conventional system weight. Within the ship body three large liquid hydrogen tanks are installed to provide 4926 m³ fuel. Consequently, bunkering stops are required on a weekly basis.