Electrification of the yacht sector via fuel cell systems for hoteling applications: A comprehensive assessment of hydrogen, ammonia, and methanol as energy carriers

he urgent need to decarbonize the maritime sector presents one of the most pressing and complex challenges in achieving global sustainability goals, given the unique energy and operational demands of vessels. This research investigates the electrification potential for covering the hoteling demands on-board a 35–45 m yacht, using hydrogen feeding proton exchange membrane fuel cells (PEMFCs). The yachting sector is here adopted as a technologically demanding case study for integrating unconventional fuels and fuel cell systems, since hoteling represents the largest share of the total onboard energy consumption and poses stringent constraints on space and safety. Various hydrogen storage methods are explored, including physical storage with compressed hydrogen and chemical storage via liquid chemical intermediates such as methanol and ammonia, to assess the most feasible solution for onboard installation. To optimize system operation, multiple fuel cell configurations are evaluated, encompassing both low-temperature (LT-PEMFC) and high-temperature (HT-PEMFC) options, along with their potential future improvements. Additionally, a seawater-cooled, liquid-based thermal management system is employed. Findings indicate that green methanol and green ammonia emerge as the most viable solutions for such application, each offering specific advantages in terms of weight impact, volume requirements, and power-to-power efficiency. Moreover, the adopted holistic approach promotes the strategic use of liquid chemical carriers and underscores the significance of efficient power devices when evaluating power-to-power scenarios, encompassing net power output and auxiliary energy consumption. Although focused on yachts, the findings of this study offer valuable perspectives that may provide insights for the development of alternative energy solutions in other maritime applications.