Dynamic Simulation and Performance Assessment of Ammonia-Based SOFC Hybrid Power Systems for Ships

Decarbonising the maritime sector demands a transition away from conventional fossil fuel combustion toward zero-carbon alternatives, yet the technical and operational implications of integrating ammonia-based power systems into existing vessel architectures remain insufficiently characterised. This study presents a dynamic simulation framework for the component sizing and performance evaluation of ammonia-based marine power systems, applied to a case study vessel across six power system configurations: a conventional MGO diesel generator baseline, an ammonia dual-fuel generator benchmark, and four hybrid configurations integrating solid oxide fuel cells at different power coverage scopes. The methodology combines an operationally based component sizing model with a time-domain dynamic simulation that captures load-dependent SOFC performance, stack degradation, transient battery buffering, heat recovery interactions, and energy management under realistic voyage conditions, a combination not previously applied to ammonia-SOFC marine power system assessment. Results demonstrate that dynamic simulation is essential for reliable sizing of transient-sensitive components, yielding battery capacities of 1500 kWh and 2900 kWh for auxiliary-only and auxiliary-plus-manoeuvring SOFC coverage scopes respectively. The ADFG–SOFC-B configuration achieves the strongest performance across all indicators: a 26.7% reduction in total annual energy consumption, a net electrical efficiency of 50.7%, and a well-to-wake GHG emission reduction of 85.6% relative to the diesel baseline. All ammonia dual-fuel configurations maintain IMO Net-Zero Framework compliance through 2039 or beyond, with SOFC-integrated configurations avoiding Tier 2 penalties through 2045. These findings establish that a full transition to green ammonia as the primary fuel, rather than SOFC integration alone, is the prerequisite for achieving both deep decarbonisation and long-term regulatory viability in maritime power systems.