Solar‐to‐Hydrogen Conversion Efficiency for Photovoltaic Water Electrolysis to Produce Green Hydrogen

Hydrogen is widely regarded as a key energy source for the 21st century, offering sustainability, environmental benefits, and energy storage capacity. Solar-powered water splitting is a frontier technology for green hydrogen production, circumventing reliance on fossil fuels. Advances in solar cells and electrocatalysis have significantly improved hydrogen production via photovoltaic-electrolysis (PV-EC). However, solar-to-hydrogen (STH) conversion efficiency is still limited by factors such as solar cell performance, electrolysis efficiency, and system integration. Optimizing these elements is essential for enhancing overall efficiency. This review focuses on the critical technologies influencing STH efficiency in PV-EC systems. Specifically, the efficiency of photovoltaic devices in harnessing solar energy, the catalytic performance of electrocatalytic materials for efficient water splitting, and the integration of solar cells with electrolyzer systems to optimize overall energy conversion. Furthermore, the latest developments and ongoing challenges in PV-EC water splitting research are explored, evaluating their economic feasibility and offering a perspective on future advancements in photovoltaic water electrolysis.