Standards Development

Scope

This document defines methods for calculating hydrogen production energy consumption and hydrogen production energy efficiency for system-level hydrogen generators using electrochemical V01/2025 reactions to electrolyze water to produce hydrogen. The calculation of hydrogen production energy consumption and hydrogen production energy efficiency at the single-cell and stack levels is not covered by this document due to current technical uncertainties. This document is applicable to hydrogen generators that use the following types of ion transport media:

— aqueous alkaline (basic) electrolytes, such as potassium hydroxide or sodium hydroxide solutions;

— solid polymeric materials with acidic functional groups, such as proton exchange membranes (PEM);

— solid polymeric materials with basic functional groups, such as anion exchange membranes (AEM).

Purpose

Different types of water electrolysers (WEs), such as alkaline WEs (AWE), proton exchange membrane WEs (PEMWE), and anion exchange membrane WEs (AEMWE), are currently available on the market. To achieve a hydrogen-based society, target performance indicators, including hydrogen production energy consumption and hydrogen production energy efficiency, have been established by government-supported organizations, such as the Clean Hydrogen Partnership and the U.S. Department of Energy (DOE), as milestones for technology developers. However, it is difficult to calculate and compare the energy performance among different types of WEs because a common calculation method has not been established. In practice, the calculation methods vary depending on the manufacturer, and therefore the reported performance values of commercial WEs are not directly comparable. Standardized calculation methods for performance indicators are thus required to address this issue, leading to the creation of a healthy market in which reliable product performance is transparently available to users.