D4a.1 Roadmap to Hydrogen Metrics Standardization

It is predicted that hydrogen will become increasingly essential in the future energy mix. Currently, the hydrogen value chain uses various metrics like kg, MWh, m³ (n), etc. This study explores the potential of adopting a single unified metric across the hydrogen value chain. Implementing a single unified hydrogen metric would promote uniformity, enhance the transactional framework for businesses, and reduce errors throughout the value chain, thereby supporting the future hydrogen development. 

A literature review, substantiated by 10+ interviews with various stakeholders in the hydrogen value chain (from producers to end users), indicates that the current metrics in use—mass-based, volume-based and energy-based—are not ideal. Instead, it is recommended to adopt exclusively energy-based metrics, preferably watt-hour (Wh). This approach offers several advantages, such as reducing confusion, simplifying the integration of green hydrogen certificates into the market, and aligning with other energy markets like the electricity market. However, there are also some pitfalls to consider, including the lack of available direct energy flow metering and the need for further clarity on ways to adopt these metrics, which are addressed in the scenario explanation but also should be addressed in future studies. 

It was found that part of the hydrogen chain, specifically mobility, recognizes the benefits but faces practical barriers to switching to (k)Wh. When the practical barriers can’t be solved an alternative can therefore be to combine energy-based and mass-based metrics. When a harmonious method of integration can be found, this is also a suitable approach that will enhance the value chain's efficiency and effectiveness. 

The study found that, while discussing about calorific values, industry prefers using the Higher Heating Value (HHV) and emphasizes to only use the energy content of the hydrogen molecules present in comparison with the total energy content (i.e., hydrogen share), this is advised to become the common practice. Additionally, the research highlights the importance of hydrogen gas quality and its compliance (in the fuel cell market) with established standards.  

To make sure that the hydrogen value chain adopts one metric, support from governmental bodies with the authority to implement changes are essential. Also a norm or standard that can be adopted by different parts of the value chain can help. Time is of the essence here, as the more time it takes, it becomes increasingly difficult to converge to a single metrics. Future studies should focus on the practical implementation of these changes and on standardizing the outcomes of this research.