In the quest to mitigate climate change and phase out the extensive use of fossil fuels, one particular element has emerged as exceptionally promising, potentially leading the way for clean fuels. This element is hydrogen. The Earth possesses an enormous supply of hydrogen. It can be utilized in the same manner as oil or gas; however, instead of generating air pollution, it merely produces water. Given its abundance and cleanliness, why isn’t it more widely embraced?
Hydrogen is the most plentiful chemical element in the universe, yet acquiring it in a pure and readily usable form remains a challenge. To leverage it like we do oil and gas, it must be produced. The issue lies in the fact that the production method often results in significant climate-warming emissions. There is little benefit to utilizing clean hydrogen energy if its production process undermines those advantages.
Challenges in hydrogen production
According to data from the International Energy Agency (IEA), a staggering 96% of hydrogen fuel generated globally relies on fossil fuels—emitting a minimum of nine tons of carbon dioxide (CO₂) for every ton of hydrogen, and in some cases, as much as twelve tons. The different production techniques employed influence the volume of CO₂ released.
Currently, the majority of hydrogen consumed—including about 95% of projects in the U.S.—is classified as gray hydrogen, produced by decomposing natural gas via high temperatures. While this method generates hydrogen, it concurrently emits approximately 12 kilograms of CO₂ for each kilogram of hydrogen produced. A more environmentally friendly alternative is blue hydrogen, which employs a similar process but integrates carbon capture technology to mitigate some emissions. Nevertheless, it still produces between three to five kilograms of CO₂ per kilogram of hydrogen.
As part of a research team exploring innovative methods to generate hydrogen without direct CO₂ emissions, Professor Graham Hutchings from Cardiff University remarked, “Identifying sustainable means to produce the essentials we require for daily life and to fulfill net-zero objectives for the future remains a significant challenge for the chemical sector. Hydrogen is broadly perceived as a viable path toward these goals since it is derived from natural gas. However, it requires substantial energy input and, of course, when generated through conventional methods, it releases considerable volumes of carbon dioxide, which diminishes its environmental advantages.”
Investigation into cleaner hydrogen production methods
One promising avenue that presents a more environmentally friendly approach is labeled as green hydrogen. This method harnesses clean and renewable energy sources, such as wind or solar power, for hydrogen production. The emissions from this process can be one kilogram or less, representing a substantial reduction compared to the existing methods for gray and blue hydrogen.
At the Massachusetts Institute of Technology (MIT) Energy Initiative, researchers are examining this concept, with a significant hurdle being the expense of the electrolyzers required to extract hydrogen from water. Additionally, the reliability of wind and solar energy for consistent production remains inadequate. This results in the need to either halt production during unfavorable conditions or revert to traditional hydrogen production methods, which contradicts the purpose.
Emre Gençer, a principal research scientist at the MIT Energy Initiative, stated, “If we develop less costly electrolyzers, we will undoubtedly witness an increase in green hydrogen availability … The reason hydrogen is a topic of discussion today
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