Enhancing Energy Efficiency in the Maritime Industry: The Role of Hydrogen Refueling Stations

Abstract This study develops and critically evaluates a renewable-powered maritime hydrogen refuelling-station (HRS) framework that couples renewable electricity generation, proton-exchange-membrane (PEM) water electrolysis, battery buffering, hydrogen compression, high-pressure storage and a vessel-demand interface. The work addresses a recurrent weakness in the literature: the tendency to assess renewable hydrogen production without closing the station-level energy balance or explicitly linking production to bunkering demand, storage pressure and operating constraints. A physically consistent screening model is formulated with a 250 kW PEM electrolyser, a 20 MWh battery, 30-to-350 bar hydrogen compression, a 1 h simulation timestep and explicit charge/discharge efficiencies. The 180 h horizon is retained solely as a short-duration benchmark because the supplied dataset contains a 180 h renewable series; it is used to examine repeated diurnal operation, short-term storage dynamics and cumulative hydrogen accounting, not to infer seasonal or annual feasibility. The renewable series are therefore treated as synthetic benchmark inputs rather than as demonstrated real-time 2025 measurements. The corrected benchmark produces 246.86 kg H2 in the solar case and 327.15 kg H2 in the wind case over 180 h, equivalent to 32.91 and 43.62 kg/day on an arithmetic-average basis. Wind therefore produces 32.5% more cumulative hydrogen over this specific benchmark horizon, whereas solar reaches a 48.5% higher maximum electrolyser input (222.06 versus 149.49 kW). Battery SOC falls from 50% to 20.32% in the solar case but increases to 89.64% in the wind case. At 55.2 kWh/kg H2, the assumed electrolyser achieves 60.4% LHV efficiency; inclusion of 2.0 kWh/kg for compression reduces the station-level LHV efficiency to approximately 58.3%. The techno-economic component is deliberately separated from the short-horizon technical benchmark. Using literature-sourced CAPEX/OPEX values and an explicit 20-year discounted-cash-flow model, the calculated LCOH at 80% utilisation decreases from 5.72 USD/kg H2 for 2 MTPD to 3.72 USD/kg H2 for 18 MTPD. These results indicate economies of scale under the stated assumptions, but they are not presented as a site-specific investment decision. The principal contribution is therefore methodological: a transparent, auditable HRS formulation that separates measured data, benchmark inputs, engineering assumptions and original calculations. Annual 8760 h site-specific meteorological data, validated vessel demand profiles and detailed component performance maps remain prerequisites for investment-grade feasibility assessment.