Hydrogen is frequently (and perennially) lauded as a versatile tool with the potential to decarbonize a wide range of industries and end-use activities. However, a more nuanced view is needed. While hydrogen has a critical role to play in the energy transition, its capabilities are often overstated. A strategic approach is necessary, focusing on areas where hydrogen is truly indispensable and avoiding its deployment where better alternatives exist.
Currently, over 96% of hydrogen production comes from fossil fuels, resulting in significant carbon emissions (Eloffy et al. 2022). This “grey” and “brown” hydrogen is entrenched in industry as a chemical feedstock for fertilizers and petrochemicals. Transitioning to cleaner production methods, such as electrolysis powered by renewables, or "green" hydrogen, is crucial for mitigating hydrogen's environmental impact.
The "Hydrogen Ladder", a framework developed by Michael Liebreich, provides a valuable tool for assessing the viability of different hydrogen applications (Liebreich 2022). The ladder categorizes applications based on their feasibility and competitiveness, ranging from "unavoidable" to "doomed".
At the top of the ladder are "unavoidable" applications, primarily hydrogen used as chemical in industrial sectors like fertilizer and steel production, and certain chemical processes. These industries require benefit from the chemical reactivity of hydrogen and specific chemical properties, like its reducing capability, that are difficult to achieve with other decarbonization technologies. Hydrogen, in these cases, is not merely a desirable alternative but a necessity.
However, the ladder also reveals areas where hydrogen is "uncompetitive". These include sectors where electrification or other alternatives offer more efficient and cost-effective solutions. Power generation, home heating, and ground transportation fall into this category, as battery technology and renewable electricity sources are rapidly advancing. Promoting hydrogen in these areas would be a misallocation of resources, diverting investment from more promising decarbonization pathways.
The allure of hydrogen's versatility is understandable. It can be used to produce electricity, heat homes, and power vehicles. However, hydrogen is not a silver bullet. The physical complexities of moving, storing, and handling hydrogen present significant challenges, like hydrogen embrittlement in steel pipelines (Barrera et al. 2018), inefficiencies associated with compressing the gas, and it propensity to leak from containers.
The production of green hydrogen is currently expensive, and the infrastructure for its widespread production is sorely lacking. For example, as electrolyzer manufacturers have not kept up with demand and have exceeded price agreements.
A more prudent approach focuses on prioritizing the "unavoidable" applications, where hydrogen offers unique chemical benefits and where viable alternatives are lacking. The International Energy Agency (IEA), once a unfettered promoter of all-things hydrogen, now echoes this sentiment, calling for more strategic and selective deployment of green hydrogen (IEA 2024). The IEA envisions a future where green hydrogen production is concentrated in "hubs" located near industrial clusters. This avoids long-distance transport and storage while enabling localized economies of scale. Shifting established large volumes of fertilizer production to green hydrogen is a top priority to transition away from fossil fuels. Supporting the high priority difficult-to-abate steel industry is urgent but is still high risk (see for example Stegra).
Ultimately, the success of hydrogen hinges on a realistic assessment of its strengths and limitations. It is not a universal solution, but a powerful tool with specific applications. By focusing on areas where green hydrogen is truly indispensable and avoiding wasteful detours, we can unlock its potential to contribute to a sustainable future.
References
Barrera, O., Bombac, D., Chen, Y., Daff, T. D., Galindo-Nava, E., Gong, P., ... & Sweeney, F. (2018). Understanding and mitigating hydrogen embrittlement of steels: a review of experimental, modelling and design progress from atomistic to continuum. Journal of materials science, 53(9), 6251-6290.
Eloffy, M. G., Elgarahy, A. M., Saber, A. N., Hammad, A., El-Sherif, D. M., Shehata, M., Mohsen, A., & Elwakeel, K. Z. (2022). Biomass-to-sustainable biohydrogen: Insights into the production routes, and technical challenges. Chemical Engineering Journal Advances, 12, 100410. https://doi.org/10.1016/j.ceja.2022.1004104
Liebreich, M./Liebreich Associates. (2023). Clean Hydrogen Ladder, Version 5.0. Concept credit: Adrian Hiel, Energy Cities. Image: Wenger (concept credit: Paul Martin). CC-BY 4.05 https://www.linkedin.com/pulse/hydrogen-ladder-version-50-michael-liebreich/
IEA. (2024). Executive summary – Global Hydrogen Review 2023 – Analysis. IEA. https://www.iea.org/reports/global-hydrogen-review-2023/executive-summary3
