Challenges and Advancements in Direct Solar PV to Water Electrolyser Technology for Hydrogen Production

Direct solar photovoltaic to electrolyser systems offer a promising pathway for producing low-carbon hydrogen, yet their performance and scalability remain limited by challenges that arise when variable solar generation is coupled to electrochemical conversion, with unresolved implications for electrolyser lifetime and hydrogen production cost. This review synthesises recent advances in photovoltaic technologies, electrolyser development and emerging deployment configurations to evaluate the technical, operational and environmental factors that shape system feasibility. The assessment draws on findings from experimental studies, modelling frameworks and techno-economic analyses to examine photovoltaic efficiency losses, thermal and material degradation, high-resolution intermittency effects, electrolyser dynamics, degradation mechanisms and storage interactions, and their combined influence on usage-dependent lifetime and cost behaviour. The results show that fluctuating solar input reduces conversion efficiency, increases transient overpotentials and accelerates degradation in both photovoltaic modules and electrolyser stacks. Technology-specific trade-offs persist, with alkaline water electrolysis constrained by limited flexibility, proton exchange membrane electrolysis by reliance on scarce catalyst materials, and anion exchange membrane and solid oxide electrolysis systems requiring further validation under real-world variability. Floating photovoltaic systems and agrivoltaics expand deployment opportunities but introduce additional constraints related to water quality, ecological impacts and power variability. Overall, the review finds that system-level integration, dynamic modelling, degradation-aware design and coordinated storage strategies are essential to unlocking reliable and scalable solar-to-hydrogen production.