Abstract
The rapid growth of renewable hydrogen highlights the necessity of reliable and sustainable hydrogen production systems, particularly for remote off-grid regions. This paper presents a rigorous and comprehensive framework for designing and evaluating solar-powered hydrogen systems integrating several unique features such as the reliability, economic performance, and environmental impact. A hierarchical energy management strategy is introduced to coordinate photovoltaic generation, battery energy storage systems, and hydrogen technologies under a firm reliability constraint and a fixed daily hydrogen delivery requirement. This framework is applied to a case study in the Pilbara region of Western Australia considering four configurations are analyzed. The configuration combining photovoltaic generation, battery storage, an electrolyzer, and hydrogen storage (PV-BESS-EL-HT) delivers the strongest overall performance, achieving a levelized cost of hydrogen of \ 3.20/kg, a levelized cost of electricity of \ 0.286/kWh, annual CO 2 avoidance of 4.12× 10⁵ kg, and very high reliability with the loss of power supply probability of 0.0002 and only 32 kWh/year of unmet load. It produces and delivers 29,970 kg/year of hydrogen while limiting curtailment to 2.12× 10⁵ kWh/year. Reliability-constrained dispatch further reduces curtailment and extends component life while maintaining competitive costs. Sensitivity analysis shows that electrolyzer's capital cost and financial parameters (e.g., the discount rate and project lifetime), have a significant impact on economic outcomes which lead to changes in the cost of up to ± 17%. Solar irradiance and electrolyzer efficiency cause variations of up to ± 12%, while battery cost has only a minor effect. By bringing together reliability, techno-economics and lifecycle environmental performance in a single assessment, the framework offers a practical way to plan off-grid renewable hydrogen projects. It gives policymakers, investors and planners useful guidance for scalable solutions in remote, resource-rich regions.