Solar-Powered Green Hydrogen from Electrolyzer (PV-H2): A Review

Abstract

This review focuses on solar-powered hydrogen production using electrolyzers. Electricity, typically generated by burning fossil fuels, remains essential but is also a major source of environmental harm. Hydrogen presents a promising alternative energy vector, capable of replacing traditional electricity generation methods and serving as an efficient energy storage medium. Among available technologies, water electrolyzers are among the most competitive systems for hydrogen production, as they emit no harmful pollutants during operation. However, hydrogen production requires energy input, and renewable sources particularly solar power offer one of the cleanest pathways for this purpose. Like other renewables, solar energy is intermittent, and such fluctuations can affect the stability and efficiency of hydrogen production systems. Directly coupling solar PV with electrolyzers offers potential cost benefits by eliminating converters and reducing conversion losses, but it also presents challenges in terms of system stability and the long-term durability of the electrolyzer. Currently, beyond conventional ground-mounted systems, alternative photovoltaic (PV) configurations are gaining attention, including floating PV (FPV), agrivoltaic PV, and building-integrated PV systems. FPV, in particular, is gaining momentum due to its close proximity to water sources, which facilitates integration with electrolyzers. Offshore FPV systems can be potential by supporting solar-powered desalination to purify seawater for electrolysis. At the gigawatt scale or above of solar-powered hydrogen production, several challenges emerge, including land use constraints, high material costs, and limited availability of resources. While electrolyzer durability is generally well understood, their long-term performance under fluctuating solar input whether through direct or indirect coupling remains under-researched, representing a significant gap in the current body of knowledge.