An advanced control method for fuel cells - Metal hydrides thermal management on the first Italian hydrogen propulsion ship

As International Maritime Organization set 2030 and 2050 targets to reduce CO2 emissions in maritime sector, the investigation of innovative clean solution as hydrogen fuel cells for clean energy generation onboard is gaining more and more value. The present study investigates the thermal integration between PEM fuel cells and metal hydrides (for hydrogen storage) on board the first Italian zero-emissions ship with hydrogen and batteries propulsion, named ZEUS, built by Fincantieri Yard and launched in 2022. A model-based approach is developed to ensure the system's control at different load demands for the vessel, including transient conditions. The study focuses on the most critical conditions for fuel cells during navigation, namely from maximum to minimum power and vice-versa. Load reduction does not imply particular issues, while load maximum increase may cause some problems in terms of stability, negatively affect fuel cell stacks lifetime. Three solutions are investigated and compared to solve the problem to achieve a safe and robust control system: (i) decrease the current ramp for fuel cells from 50 to 10 A/s; (ii) introduce an intermediate load step; (iii) adopt an advanced Model Predictive Control strategy.