How advanced is hydrogen leak detection—are the technologies used sufficiently accurate and reliable? Can hydrogen in the atmosphere impact global warming?

Commercial hydrogen detection technologies are currently used in industrial and research settings to protect workers from fire hazards resulting from significant leaks. However, highly sensitive hydrogen detection is a nascent area, and lower-cost, more-sensitive hydrogen sensors are needed to detect the smaller hydrogen leaks that may not pose safety risks but can have potential secondary global warming impacts. The U.S. Department of Energy (DOE) supports ongoing research and development to advance tools for accurately measuring very small hydrogen losses (measurable on a parts-per-billion scale), as well as leak-mitigation technologies.^1,2,3 DOE also works closely with other agencies through the Hydrogen Interagency Task Force to both better understand the impacts of hydrogen leaks and to ensure the most effective implementation of new detection and mitigation technologies across the value chain.

Hydrogen itself is not a greenhouse gas; however, research shows that hydrogen released into the atmosphere can interact with other gases and extend the global-warming impact of methane, a powerful greenhouse gas, and it contributes to ground-level ozone. Intentional hydrogen releases, such as venting and purging processes, account for the majority of hydrogen released into the atmosphere today, and DOE is continuing to support technology advancements to mitigate these releases. There is currently no evidence to suggest that unintentional hydrogen releases, such as leaks, would significantly offset the climate benefits of using clean hydrogen. Furthermore, improvements in leak detection and prevention offer clear pathways to mitigate any negative secondary climate impacts related to leaks. DOE has provided more than $25 million in funding for new projects to develop better sensors to detect hydrogen leaks.^4,5

Along with partners in the European Commission, DOE's Hydrogen and Fuel Cell Technologies Office co-led the "Clean Hydrogen Joint Undertaking Expert Workshop on the Environmental Impacts of Hydrogen" in March 2022. A report on this meeting contains a thorough discussion of the technical and knowledge gaps related to atmospheric models, sensor and monitoring technology, and estimated hydrogen losses.⁶ Workshop findings reinforced that more research is needed to understand the impact of hydrogen in the atmosphere. 

DOE is coordinating with the National Oceanic and Atmospheric Administration to improve existing climate models to further understand the global hydrogen cycle and the impacts of hydrogen leakage.⁷ This collaboration also supports collection of atmospheric data and strengthening of hydrogen measurement techniques, as well as future updates to state-of-the-art life cycle assessment tools, such as the Greenhouse Gases, Regulated Emissions, and Energy Use in Technologies (GREET) model, to fully reflect these effects.