PREVENTING HYDROGEN LEAKS: EXPLAINED

Hydrogen is the most abundant element in the universe and has immense decarbonization potential across multiple sectors of the economy. If hydrogen use is to be leveraged to decarbonize across industries and sectors, addressing technical risks like leakage will be essential to realize hydrogen’s full climate potential.

Efficient and secure hydrogen infrastructure that limits potential leakage will drive innovation and enhance environmental benefits. Creating a clean hydrogen ecosystem that minimizes potential risks is a top priority for the industry.

Hydrogen’s versatility makes it a central component to achieving economy-wide net-zero emissions. Governments worldwide have recognized this potential, as evidenced by over 30 hydrogen strategies and roadmaps, including the recent U.S. National Clean Hydrogen Strategy and Roadmap released in 2023.

One question that has arisen relates to potential hydrogen leakage, with some raising the concern that hydrogen is an indirect greenhouse gas that will prolong the life of methane in the atmosphere and increase its warming potential. It is important to start with the basic fact that hydrogen has been produced, transported, and used safely for decades, with industry having developed technologies and best practices to mitigate such risks. As hydrogen takes off as part of a clean energy economy and more hydrogen is produced, transported, and used, it is critical to ensure the commitment from all stakeholders to “get hydrogen right” from the start.

 

What We Know About Potential Hydrogen Leakage

Data from existing operations and credible analyses consistently show that hydrogen leakage is minimal and well managed, and that advancements in the years ahead will reduce leakage rates further.

Columbia’s Center on Global Energy Policy found that local distribution pipelines “are the most important systems for hydrogen delivery” and pose a very low 0.4% leakage rate. The Columbia report acknowledges that future build out of the hydrogen infrastructure system will need to emulate this highly efficient hydrogen delivery method.

An analysis from the Rocky Mountain Institute (RMI) notes that hydrogen leakage during production “can be minimized easily at scale with today’s technologies and operational best practices.” In assessing the potential warming risk of hydrogen leakage, RMI reviewed existing literature and assumed loss rates of 0.01-2.1% for production, 0.04-0.05% for transmission, 1.0-2.0% for storage, and less than 0.5% for distribution. Moving forward, RMI notes that “[d]eveloping robust leak prevention technologies through improved connectors, compressors, and storage vessels will enable new systems to be nearly leak-proof.”

Additionally, the International Energy Agency (IEA) has developed projections for potential hydrogen leakage by 2050. These are based on 2020 global data, extrapolated to reflect the expansion of the hydrogen economy. IEA’s low-risk 2050 case estimates a leakage rate of 2.9%, just 0.2 percentage points higher than 2020 levels. The high-risk case estimates leakage levels at 5.6%. It must be the priority for industry and regulators to ensure the eventual outcome hews closer to or betters the low-risk case.

Similarly, a study from the Frazer-Nash Consultancy assessed and quantified likely fugitive hydrogen emissions in a future 2050 hydrogen economy and determined that likely leakage will be quite low, ranging from 0.96-1.5% across the supply chain.

 

Current Challenges and Existing Solutions

Certain leakage risks, including embrittlement of steel pipelines, are both observable and manageable that can and should be addressed. When distributed through a steel pipeline, hydrogen can embrittle the steel over a period of several decades. Much of the steel pipelines still in operation today are being replaced with polyethylene (plastic) pipes, which do not embrittle with hydrogen. Because embrittlement can be observed over time, technicians can mitigate the risk and replace older steel pipelines.

Existing natural gas pipelines offer a promising future transport mode for clean hydrogen. While hydrogen has different characteristics compared to natural gas (smaller molecule, energy density, etc.), research from the National Fuel Cell Research Center observed hydrogen and natural gas leaks at the same low-volume levels within a low-pressure natural gas pipeline system. Deploying leak detection systems, an already common practice for natural gas and for hydrogen-specific pipelines, will help mitigate these risks and allow technicians to address any leaks that may occur to the extent that hydrogen is injected into natural gas pipelines in the future.

Source: Hydrogen leaks at the same rate as natural gas in typical low-pressure gas infrastructure (IJHE – Hormaza Mejia, Brouwer, Mac Kinnon)

A recent study by the California Public Utilities Commission (CPUC) and the University of California, Riverside found that hydrogen blends of up to 5 percent in the natural gas stream are generally safe with current infrastructure and would not increase the likelihood of leaks. It is critical to conduct real-world demonstrations of hydrogen under safe and controlled conditions to understand the limits and versatility of existing infrastructure.

Leakage can occur at various points in the hydrogen supply chain, so it is crucial that established industry best practices are applied broadly. Industry leaders with decades of experience in safely handling hydrogen, as well as organizations like the Center for Hydrogen Safety, are critical to ensuring that innovations to address hydrogen leakage and safety protocols are widely distributed and shared. The Center for Hydrogen Safety maintains a comprehensive listing of lessons learned covering all areas of the hydrogen value chain that form a collective tool for education, awareness, and ultimately a safer hydrogen economy.

 

The Bottom Line

The hydrogen industry has safely and effectively managed leakage risks over many decades and looks forward to working with new participants in the hydrogen value chain to ensure that that those practices and risk management approaches are widely employed as the  U.S. clean hydrogen economy grows as an essential party of the strategy to achieve net-zero emissions.

 

More resources on hydrogen safety:

• Center for Hydrogen Safety (CHS) – The Center for Hydrogen Safety is a global, neutral and nonprofit membership organization that supports and promotes the safe handling and use of hydrogen across industrial and consumer applications in the energy transition. The Center facilitates access to hydrogen safety experts; develops comprehensive safety guidance, outreach and education materials and activities; and provides a forum to partner on worldwide technical solutions.
• Pipeline and Hazardous Materials Safety Administration (PHMSA) – PHMSA oversees the transportation of hazardous materials, including energy products, through all modes of the transportation industry—and is focused on the Biden-Harris Administration’s whole-of-government approach to mitigating climate change.
• Safe Hydrogen Project – The Safe Hydrogen Project is a collaborative global effort to develop and distribute safety information for the production, storage, transport, and use of hydrogen. The Safe Hydrogen Project is an initiative of the Compressed Gas Association (CGA) which has been a global leader in hydrogen safety for more than 70 years.
• H₂ Incidents: Hydrogen Incident Reporting Tool – This website records events involving hydrogen and hydrogen-related technologies.