Challenges in Electrolyzer Performance Evaluation for Green Hydrogen Production

The transition to sustainable energy increasingly relies on hydrogen gas produced by water electrolysis. Current performance metrics for electrolyzers, typically measured in megawatts or kilowatts, inadequately capture the full scope of the system efficiency and hydrogen output rates. The gap between academic and industrial evaluations can distort the perceived effectiveness of these technologies. This Perspective proposes a refined dual-metric evaluation system that integrates both energy efficiency (kWh/kg H₂) and production rate (Nm³/h) to provide a balanced view of performance. A standardized framework similar to that for photovoltaic technologies is suggested to enable transparent comparisons and support advancements in electrolyzer design. Emphasizing the need for consistent testing conditions, the framework aims to ensure that the evaluations of the electrodes, stacks, and overall systems remain reliable across various operational scenarios. Adopting such a comprehensive evaluation approach is essential for accurately communicating the capabilities of water electrolyzers and propelling the widespread use of green hydrogen.