Detroit's Hydrogen Engine Moment: The Combustion Engine Is Ready, but Is the Hydrogen Economy?
In mid-September 2026, engine builders, fleet operators, and national laboratory researchers gathered at Huntington Place in Detroit for the Fall 2026 North American Hydrogen Engine Conference. The host, the Hydrogen Engine Alliance of North America (H2EA-NA), was inspired by Germany's Allianz Wasserstoffmotor and counts Bosch, Chevron, Cummins, Daimler Truck North America, FORVIA, MAHLE, Tenneco, the University of California Riverside, and the University of Michigan among its founding members. Its stated mission is to "accelerate the adoption and commercialization of hydrogen engine technologies across North America" (H2EA-NA, n.d.). One message came through clearly. The hydrogen internal combustion engine (H2-ICE) has largely cleared its technical hurdles, and the harder question now is whether the hydrogen supply chain can keep pace.
The hardware evidence was striking. Daimler Truck North America described a hydrogen demonstrator built on its 15.6 liter DD16 platform that shares 80 percent of its parts with the diesel version, produces 350 kW, and exceeds 45 percent engine efficiency with near zero CO2 and NOx using conventional aftertreatment (Braziunas, 2026). Daimler has also partnered with KEYOU to bring a hydrogen combustion tractor to Europe in 2027. A Department of Energy project panel reported that a Cummins 15 liter hydrogen engine delivered tailpipe NOx below 0.01 g/hp-hr across every certification cycle, well under the 0.035 g/hp-hr limit for model year 2027 diesel, while cutting tailpipe CO2 by 99.9 percent and reaching 44 percent brake thermal efficiency (Peters et al., 2026). The same panel outlined a
Dumarey led effort with John Deere, MAHLE, Oak Ridge, and Argonne to match diesel power density in a 13.6 liter engine, with multicylinder testing scheduled from late 2027 into 2028.
Researchers were direct about emissions. Stefan Sterlepper of RWTH Aachen asked whether hydrogen engines can achieve zero impact tailpipe emissions and answered yes, provided engineers manage dynamic NOx peaks and secondary particles from urea injection that diesel soot normally masks (Sterlepper, 2026). His verdict was that emissions "can be controlled (no showstopper!)." Oak Ridge National Laboratory found that placing an oxidation catalyst ahead of a combined iron and copper SCR system offers the best balance of NOx conversion and low nitrous oxide formation (Peters et al., 2026).
Work remains. Infineum's Carina Foster explained that hydrogen combustion generates four times more water than diesel and that pre-ignition is now the primary concern shaping lubricant formulation (Foster, 2026). Margaret Wooldridge of the University of Michigan showed that hydrogen is far more sensitive to temperature gradients than conventional fuels, which explains abnormal ignition behavior that models long failed to predict (Wooldridge, 2026). Colorado State University researchers converted a small Kohler engine for a fuel cell hybrid power system and measured 18.5 percent efficiency on hydrogen versus 25.8 percent on methane, a reminder that small engines still lag (Rubio Estrada, 2026).
Applications extend beyond trucks. Sandia National Laboratories traced how its early ferry studies led to the Sea Change, the first commercial hydrogen ferry in the United States, and influenced Viking's hydrogen cruise ships carrying roughly 6,000 kg of liquid hydrogen (Klebanoff, 2026). In-Gas Solutions presented hydrogen engine generators from 20 to 150 kVA, noting that combustion engines tolerate lower hydrogen purity than fuel cells and that DILO alone deploys 20 to 30 diesel powered substation trailers every year (Laverne, 2026).
So what does this mean for the hydrogen economy? The bottleneck has moved from the engine to the molecule. Southwest Research Institute's Thomas Briggs modeled refuse trucks for the City of San Antonio and found the lowest hydrogen price at the pump was $10.93 per kilogram, leaving hydrogen combustion trucks with a total cost of ownership 1.85 times that of diesel (Briggs, 2026). Scaling production 100 times cut production cost by roughly 75 percent, but liquefaction for long distance delivery adds $3 to $5 per kilogram. His conclusion was that "large regional production hubs with multiple end users are needed."
FORVIA's Tarek Abdel-Baset argued that the industry went "too big, too perfect, too fast" and should now target applications where diesel parity sits at $12 to $15 per kilogram, such as refuse trucks, yard rail, and tugs, using modular stations costing $1 million to $4 million rather than $10 million to $20 million (Abdel-Baset, 2026). Detroit is testing that approach with two hydrogen refuse trucks, compressed gas supply, and a Bosch electrolyzer in Farmington Hills producing up to 550 kg per day. Michigan's case rests on border crossings, Great Lakes shipping, salt formations for storage, and a deep manufacturing base (Bari, 2026).
Safety is the other gatekeeper. The Center for Hydrogen Safety counted 31 significant global hydrogen incidents and 18 fatalities between September 2025 and September 2026, and warned that "the companies that win in hydrogen won't be the fastest. They'll be the safest" (Barilo, 2026). Livio Gambone urged a defense in depth design philosophy and standardized first responder markings across manufacturers (Gambone, 2026).
H2-ICE offers the hydrogen economy something it badly needs, which is dependable offtake. Engines reuse existing factories, supply chains, and technician skills, so they can create hydrogen demand faster than any alternative drivetrain. As Sterlepper put it, "hydrogen offtake is the key enabler for the hydrogen economy." Yet no engine can fix an $11 kilogram. The engine is ready, and the next phase belongs to producers, hub developers, and regulators who can deliver affordable, safe hydrogen to captive, return to base fleets first.
References
Abdel-Baset, T. (2026, September). Michigan's hydrogen future: Detroit, epicenter of hydrogen ecosystem acceleration [Conference presentation]. Fall 2026 North American Hydrogen Engine Conference, Detroit, MI, United States.
Bari, S. (2026, September). H2 in Michigan: What makes us unique [Conference presentation]. Fall 2026 North American Hydrogen Engine Conference, Detroit, MI, United States.
Barilo, N. (2026, September). Hydrogen safety: Safety builds public confidence [Conference presentation]. Fall 2026 North American Hydrogen Engine Conference, Detroit, MI, United States.
Braziunas, G. (2026, September). Shaping the future of hydrogen: Daimler Truck's heavy duty engine journey [Conference presentation]. Fall 2026 North American Hydrogen Engine Conference, Detroit, MI, United States.
Briggs, T. (2026, September). Cost drivers and trade-offs for truck fleet decarbonization using hydrogen fuel [Conference presentation]. Fall 2026 North American Hydrogen Engine Conference, Detroit, MI, United States.
Foster, C. (2026, September). Formulating engine lubricants for H2ICE applications [Conference presentation]. Fall 2026 North American Hydrogen Engine Conference, Detroit, MI, United States.
Gambone, L. (2026, September 16). Best practices for ensuring hydrogen vehicle safety [Conference presentation]. Fall 2026 North American Hydrogen Engine Conference, Detroit, MI, United States.
Hydrogen Engine Alliance of North America. (n.d.). About H2EA-NA. Retrieved September 28, 2026, from https://h2engine-alliance.org/
Klebanoff, L. (2026, September 16). H2 powered ships: From feasibility studies to first approved vessels [Conference presentation]. Fall 2026 North American Hydrogen Engine Conference, Detroit, MI, United States.
Laverne, R. (2026, September). Advancing hydrogen solutions for the next generation of ICE technology [Conference presentation]. Fall 2026 North American Hydrogen Engine Conference, Detroit, MI, United States.
Peters, N., Bieneman, J., Prikhodko, V., Sinha Majumdar, S., Whajah, B., Chen, H.-Y., & Hoth, A. (2026, September 15). DOE project panel: High power, ultra-low emissions HD H2 engine [Panel presentation]. Fall 2026 North American Hydrogen Engine Conference, Detroit, MI, United States.
Rubio Estrada, E. (2026, September 16). Development of a hydrogen-capable engine for use in a SOFC/engine hybrid CHP system [Conference presentation]. Fall 2026 North American Hydrogen Engine Conference, Detroit, MI, United States.
Sterlepper, S. (2026, September 16). Thermodynamics of mobile energy on the way to zero-impact emissions with hydrogen engines [Conference presentation]. Fall 2026 North American Hydrogen Engine Conference, Detroit, MI, United States.
Wooldridge, M. (2026, September 16). Some insights into "abnormal" hydrogen combustion behavior [Conference presentation]. Fall 2026 North American Hydrogen Engine Conference, Detroit, MI, United States.
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