Fueling the Future: From Grey to Green Hydrogen

By Kristen Abels

Gas stations on every other corner are commonplace, but what if they weren't? What if gasoline was not our go-to fuel? Hard to imagine, I know. But just last year, I saw something that made this idea a great deal more concrete: a hydrogen fuel station. Now this was in California, where most of North America’s hydrogen fuel stations reside. But still, what an exciting sight to see!

While we might not all be fueling our cars with hydrogen any time soon, industrial-scale hydrogen production is already commonplace around the world, as hydrogen is a well-established commodity chemical used as a feedstock in various applications – one major one being ammonia fertilizer production. The problem is, not all hydrogen is created equally.

Original image can be found here.

Out of the 80 million tons of hydrogen produced annually, over 95% of it is derived from fossil fuels through the process of steam methane reforming [1]. This process, which emits 10 kilograms of carbon dioxide for every kilogram of hydrogen produced, is certainly not what we want in our low-carbon economy of the future. The alternative ‘green’ hydrogen – that is, hydrogen produced by renewable energy-powered water electrolysis – is what we need to eliminate these carbon emissions. The problem is, this grey hydrogen is currently ten times cheaper (on average) to produce compared to its green hydrogen cousin [2].

Out of the 80 million tons of hydrogen produced annually, over 95% of it is derived from fossil fuels through the process of steam methane reforming [1]. This process, which emits 10 kilograms of carbon dioxide for every kilogram of hydrogen produced, is certainly not what we want in our low-carbon economy of the future. The alternative ‘green’ hydrogen – that is, hydrogen produced by renewable energy-powered water electrolysis – is what we need to eliminate these carbon emissions. The problem is, this grey hydrogen is currently ten times cheaper (on average) to produce compared to its green hydrogen cousin [2].

Fortunately, researchers around the world are working to shrink this price gap through technological innovation. When envisioning a commercial-scale green hydrogen plant of the future, Professor Thomas Jaramillo of Stanford University estimates that a target capital expenditure (CAPEX) of $0.30/kg or less will be needed to ensure profitability. PROTON Onsite, a world-leader in polymer electrolyte membrane electrolyzer development and application, recently performed a techno-economic assessment of a conceptual 50 ton/day green hydrogen plant. The anticipated CAPEX was calculated as $0.50-0.60/kg, so we’re really not too far off. Given that 54% of this CAPEX comes from electrolyzer costs, technological advancements may be game-changing in the near future! The falling costs of electricity can only help us achieve this target. For instance, reductions of precious metal loadings in polymer electrolyte membrane electrolyzers is an active area of research in reaching this goal [3].

Green hydrogen for chemical feedstocks is not the only facet of a green hydrogen economy; as the global renewable energy capacity increases, it may also come to serve as a primary source of surplus energy storage. Just this year, ambitious plans for Hyport Oostende in Belgium have been unveiled, which is set to be the first commercial-scale green hydrogen plant built for this purpose with the hydrogen produced to satisfy all sorts of chemical and energy needs [2].

So while we might not see hydrogen fueling stations replacing our gas stations any time soon, the applications of hydrogen are far broader than transportation alone. Indeed, the hydrogen economy is already well-established. Even though grey hydrogen remains at its core, rest assured that green hydrogen is gaining its foothold in our low carbon economy of the future.

[1] “At the Dawn of the Hydrogen Economy.” [Online]. Available: https://www.powermag.com/at-the-dawn-of-the-hydrogen-economy/. [Accessed: 25-Sep-2020].

[2] “World’s first commercial green H2 project powered by surplus renewables unveiled | Recharge.” [Online]. Available: https://www.rechargenews.com/transition/worlds-first-commercial-green-h2-project-powered-by-surplus-renewables-unveiled/2-1-744835. [Accessed: 25-Sep-2020].

[3] “Thomas Jaramillo: Developing New Catalysts and Sustainable Processes for the Production - Bing video.” [Online]. Available: https://www.bing.com/videos/search?q=jaramillo+hydrogen+economy&&view=detail&mid=B197EFB5FA33D34CB3F7B197EFB5FA33D34CB3F7&&FORM=VRDGAR. [Accessed: 25-Sep-2020].

[4] V. A. Kulagin and D. A. Grushevenko, “WILL HYDROGEN BE ABLE TO BECOME THE FUEL OF THE FUTURE?,” Therm. Eng., vol. 67, no. 4, pp. 189–201, 2020, doi: 10.1134/S0040601520040023.