The Viability of Green Hydrogen as a Primary Fuel for Heavy Industry and Aviation

As the global community accelerates its transition toward net-zero carbon emissions, attention has increasingly turned to sectors traditionally deemed “hard to abate.” While passenger vehicles and light-duty transport are rapidly embracing direct electrification through lithium-ion batteries, sectors such as steel manufacturing, chemical production, and long-haul aviation require energy densities and chemical properties that current battery technology simply cannot provide.

Enter green hydrogen—hydrogen produced via the water electrolysis powered exclusively by renewable energy sources such as wind, solar, or hydro. Proclaimed by many as the “Swiss Army knife” of the energy transition, green hydrogen holds transformative potential. However, its long-term viability as a primary fuel for heavy industry and aviation is a complex equation balancing technological promise against formidable economic and infrastructural hurdles.

1. Transforming Heavy Industry: Steel and Chemicals

Heavy industry accounts for a substantial share of global greenhouse gas emissions, primarily driven by high-heat requirements and chemical processes dependent on fossil fuels. Green hydrogen offers a revolutionary pathway to decarbonize these sectors.

The Steel Sector and Green Iron

Traditional steelmaking relies heavily on coking coal to strip oxygen from iron ore in a blast furnace, releasing massive quantities of carbon dioxide. Green hydrogen enables Direct Reduced Iron (DRI) production, where hydrogen acts as the reducing agent instead of carbon. The byproduct of this reaction is water vapor rather than carbon dioxide. Pioneer projects—such as Sweden’s HYBRIT initiative and H2 Green Steel—have demonstrated the technical feasibility of fossil-free steelmaking, proving that green hydrogen can successfully replace coal at an industrial scale.

Chemical Feedstocks

Beyond steel, heavy industry relies on hydrogen as a fundamental chemical feedstock, predominantly for producing ammonia (for fertilizers) and methanol. Currently, this hydrogen is overwhelmingly “grey”—produced from natural gas via steam methane reforming, which generates significant emissions. Transitioning to green hydrogen in ammonia and chemical synthesis is not only technically straightforward but also critical for decarbonizing the global agricultural and manufacturing supply chains.

2. Decarbonizing Aviation: Direct Hydrogen vs. E-Fuels

Aviation is responsible for roughly two to three percent of global CO2 emissions. Because of weight and energy density constraints, battery-electric flight is restricted to short-haul regional routes. For medium- and long-haul aviation, green hydrogen is viewed as a vital solution, manifesting in two distinct ways:

• Direct Liquid Hydrogen Combustion and Fuel Cells: Storing cryogenic liquid hydrogen onboard aircraft can provide the necessary energy density by weight, though it requires significantly more volume than conventional jet fuel. This necessitates entirely new aircraft architectures (such as blended-wing-body designs) and specialized cryogenic fueling infrastructure at airports.
• Synthetic Aviation Fuels (Power-to-Liquids / PtL): Alternatively, green hydrogen can be combined with captured carbon dioxide to synthesize “drop-in” e-fuels. These synthetic kerosene alternatives are chemically identical to conventional jet fuel, meaning they can be burned in existing aircraft engines and transported through current fueling infrastructure without modification.

While e-fuels avoid the monumental cost of redesigning the global commercial fleet, they suffer from high energy conversion losses. Direct hydrogen combustion remains more efficient overall, but demands a complete overhaul of airport logistics and aircraft design.

3. The Roadblocks: Economic and Infrastructural Challenges

Despite its theoretical brilliance, green hydrogen faces major headwinds that complicate its widespread commercial viability.

High Production Costs and the “Hydrogen Ladder”

The levelized cost of green hydrogen (LCOH) remains higher than that of fossil-derived grey or blue hydrogen (which uses carbon capture). Electrolyzers are capital-intensive, and the cost of renewable electricity—though falling—must drop even further to make green hydrogen economically competitive. Furthermore, using hydrogen for applications where direct electrification is feasible (such as heating or light vehicles) is inefficient due to substantial energy losses incurred during conversion, compression, storage, and reconversion.

Infrastructure Deficits

Hydrogen is the smallest molecule in the universe, making it notoriously difficult to store and transport. It causes embrittlement in standard steel pipelines, requiring dedicated new pipelines, specialized high-pressure storage vessels, or cryogenic tankers. Building a global supply chain for liquid hydrogen transport mirrors the multi-decade buildout of the global liquefied natural gas (LNG) market, requiring immense capital investment and international coordination.

Conclusion

Green hydrogen is not a silver bullet, but it is an indispensable piece of the net-zero puzzle. For heavy industry and aviation, it represents one of the only viable pathways to deep decarbonization where batteries fall short.

Its ultimate viability will depend heavily on supportive government policies—such as robust carbon pricing, production tax credits, and mandates for sustainable aviation fuels—alongside sustained technological innovation to lower electrolyzer costs. As renewable energy capacity expands globally through the late 2020s and into the 2030s, green hydrogen is poised to transition from a promising scientific frontier into the operational backbone of a clean industrial economy.