Abstract

The decarbonization of productive sectors has prompted many countries to develop national hydrogen roadmaps, with green hydrogen as a key solution. Off-grid photovoltaic hydrogen production offers a promising pathway, particularly in remote areas, leveraging low-cost solar energy and curtailment scenarios. However, the inherent intermittency of solar resources requires advanced configurations and hybrid energy storage systems to ensure efficient and stable electrolyzer operation. This review examines the requirements for an effective off-grid photovoltaic system for green hydrogen production, considering the current political landscape and various configurations and technologies presented in the literature and industry. This review introduces a classification of key power-electronics topologies, electrolyzer technologies, and hybrid energy-storage configurations, and examines the integration challenges associated with each category. Rather than treating these technologies as isolated options, the review critically compares the trade-offs among architectural simplicity, electrolyzer protection, storage buffering, commercial availability, and deployment feasibility under off-grid PV variability. It distills data from commissioned projects worldwide, highlighting trends in system design, technology selection, and end-use applications by identifying critical research gaps such as component degradation, scalability, and dynamic modeling. This work highlights future research trends to reduce the levelized cost of hydrogen and accelerate its deployment in off-grid environments, providing support to researchers and practitioners in designing robust, efficient, and replicable off-grid green hydrogen solutions.