Abstract
This paper establishes a framework of boundary conditions for implementing hydrogen energy systems in ships, identifying what is feasible within maritime constraints. To support a comprehensive understanding of hydrogen systems onboard vessels, an extensive technical review of hydrogen storage and power systems is provided, covering the entire power value chain. Key aspects include equipment arrangement, integration of fuel cell powertrain, and presentation of the complete storage system, in compliance with regulations. Engineering considerations, such as material selection and insulation, equipment specifications (e.g., pressure relief valves and hydrogen purity), and system configurations are analysed. Key findings reveal that fuel cells must achieve operational lifespans exceeding 46,000 h to be viable for maritime applications. Additionally, reliance solely on volumetric energy density underestimates storage needs, necessitating provisions for cofferdams, ullage space, tank heels, and hydrogen conditioning areas. Regulatory gaps are identified, including inadequate safety provisions and inappropriate material guidelines.