Hydrogen Projects Should Include The Likelihood of Leakages with Dr. Ilissa Ocko, Senior Climate Scientist, Environmental Defense Fund, United States

Did you know that Hydrogen has indirect warming impacts? In a July 2022 study centered on the climate consequences of hydrogen emissions, it was stated that hydrogen's warming effects have major implications for an emerging hydrogen economy because hydrogen is a tiny molecule that is hard to contain.

It can leak across the entire value chain, including electrolyzers, compressors, liquefiers, storage tanks, geologic storage, pipelines, trucks, trains, ships, and fueling stations. Hydrogen's indirect warming potency per unit mass is around 200 times that of carbon dioxide and larger than that of methane.

However, like methane, hydrogen's warming effects are potent but short-lived. Some of the hydrogen's effects are shorter-lived than methane's – occurring within a decade after emission – but its impacts on methane can affect the climate for roughly an additional decade.?

Link to Image Source

Hydrogen leakage poses a risk to decarbonization goals, given its potency as an indirect greenhouse gas, there are several challenges associated with determining the overall magnitude and, thus, the importance of its warming impacts on the effectiveness of hydrogen as a decarbonization strategy.

Dr. Ilissa Ocko is a Senior Climate Scientist and Barbra Streisand Chair of Environmental Studies at Environmental Defense Fund, a United States-based non-profit environmental advocacy group. Energy! reached out to her to provide more insights on this subject matter.

Will there be a point where green hydrogen becomes completely climate neutral?

It’s going to be hard for anything to be completely climate neutral in the near term because right now even building wind turbines and solar panels will emit some carbon dioxide. But in terms of green hydrogen specifically, what we are worried about is that hydrogen, a tiny molecule that can easily leak from infrastructure, can indirectly warm the climate when it escapes into the atmosphere. If we are able to keep leaks to a minimum, green hydrogen can be really close to climate neutral. But first, we need the technology to measure leakage to assess how big of a problem leakage is in the industry. Then we can assess mitigation measures to see how possible it is to drive down leakage as we scale up infrastructure.

A new network of production facilities, pipes, storage tanks, and hydrogen-powered homes and vehicles could create a vast potential for hydrogen to leak - Study

As Africa looks to develop green hydrogen projects, what factors do you think are important for the continent to focus on to avoid contributing more to global warming?

It is important for any green hydrogen project to immediately include the likelihood of hydrogen leakage and its associated impacts in decisions about where and how to deploy hydrogen effectively. For example, to minimize leakage, deployment should be concentrated in industries where the hydrogen is produced and used in close proximity, with a limited need to transport it. However, given that parts of Africa (such as South Africa) want to become major exporters of green hydrogen, it will be critical to make sure that the transport of hydrogen is carefully monitored and credibly shown to have low leakage rates. Finally, given the high capital cost of and energy needed to produce hydrogen (in addition to leakage concerns), it is key to support the direct use of renewable energy wherever possible – as opposed to using the renewable energy to produce hydrogen and then convert the hydrogen back into electricity.

Will data on green hydrogen emissions help in establishing a solid green hydrogen industry in Africa?

Good data on emissions is essential. We need science- and data-driven information to make the most effective decisions about hydrogen and minimize risks to the climate. If Africa can credibly show with empirical measurements that hydrogen emissions are low, it would empower the green hydrogen industry in Africa to claim near-zero climate effects that are maximizing the climate benefits of using hydrogen instead of fossil fuels.

While zero- and low-carbon hydrogen hold great promise to help solve some of the world's most pressing energy challenges, hydrogen is also an indirect greenhouse gas whose warming impact is both widely overlooked and underestimated - Study

In terms of research and development, what can African hydrocarbon operators who plan to transition from natural gas to green hydrogen, do to avoid causing more harm to the environment???

First, we need accurate measurements of hydrogen emissions, which will require new sensors that are able to measure hydrogen emissions at the ppb scale (far below safety hazard levels). Then it is important to identify leakage mitigation measures and best practices so that they can be deployed as projects scale up. Leakage detection and repair programs for all hydrogen projects will be essential to keep leaks to a minimum. Finally, we also need to consider other environmental concerns of deploying hydrogen at scale, such as the production of Nitrogen Oxide when hydrogen is burned. Nitrogen Oxide is a harmful air pollutant and could have health implications for local communities. Therefore, we need to minimize Nitrogen Oxide emissions in addition to hydrogen.

Can we say that hydrogen leakages and methane emissions pose the same amount of danger to the environment?

While methane and hydrogen can trap a similar amount of heat in the climate for equal mass, we emit a lot more methane in mass than we do hydrogen. Further, methane itself can trap heat (in addition to triggering chemical reactions that increase amounts of other greenhouse gases) whereas hydrogen cannot trap heat by itself but only through chemical reactions. Finally, methane affects the climate for a slightly longer period than hydrogen. All of these factors combined lead to methane being the larger concern for the climate, but that is not a reason to ignore hydrogen emissions and their potential contribution to climate change.

Minimizing leakage will be essential to the effectiveness of hydrogen as a climate change mitigation strategy

Energy! Notes

In the study earlier cited, Dr. Ilissa Ocko and Steven P. Hamburg give the following key actions that can help minimize hydrogen's warming effects and, therefore, maximize climate benefits in a future hydrogen economy:

1. Advance research of hydrogen's indirect radiative effects and temperature responses to hydrogen emissions by incorporating interactive emissions, chemistry, and radiation parameterizations in further coupled chemistry-climate models as well as reduced-complexity climate models;
2. Employ climate metrics and/or models that effectively reflect the role that hydrogen could play in meeting net-zero goals in the desired time frames – this means not exclusively relying on GWP-100 and potentially adopting a dual GWP-20/GWP-100 approach (Ocko et al., 2017);
3. Improve quantification of hydrogen leakage rates by developing technologies that can be taken into the field to accurately measure hydrogen emissions at low detection thresholds (i.e., ppb level);
4. Include the likelihood of hydrogen leakage and its impacts in decision-making about where and how to effectively deploy hydrogens – such as co-located production and end-use applications; and
5. Identify leakage mitigation measures and best practices before building out infrastructure.