United States’ First Class 8 H2-ICE Demo Showcased for Fleets

After working with Cummins Inc. and other major industry suppliers to slash emissions with a hydrogen internal combustion engine (H2-ICE), Southwest Research Institute is moving onto the next phase of its H2-ICE Consortium - drawing on real-world expertise from fleets.

SWRI announced earlier this year that its converted hydrogen engine nearly eliminated tailpipe nitrogen oxides (NOx) with a massive drop to .0008 g/hp-hr. The R&D non-profit reported that the results are “more than four times lower than the EPA 2027 limit and still well below the CARB Ultra-low NOx standard.” Carbon dioxide (CO2) levels plummeted 99.7% compared to diesel during the federal test procedure (FTP) cycle.

The institute credits key partnerships for the unprecedented numbers.

As a member of the H2-ICE Consortium, Cummins supplied SWRI with an X15N natural gas engine from the new Cummins HELM™ fuel agnostic platform. SWRI then converted the engine to run on hydrogen.

“It was one of the first X15N engines that we built that shipped external to Cummins,” said David King, Cummins North American On-Highway Product Manager for Natural Gas and Hydrogen  Engines. “It's impressive what they've been able to do with all the participants in the program bringing their bits and pieces so to speak.”

Consortium members also include Bosch and Phinia which provided hydrogen injectors. Mechanically-driven boosting came courtesy of SuperTurbo. MAHLE’s active blower system provided crankcase ventilation. A capacitive discharge ignition system came from SEM. The port-injected engine powers an International LT sleeper cab.

SWRI’s manager of spark ignition R&D, Ryan Williams, said the main effort behind the first phase of the H2-ICE Consortium “was to get the vehicle built and show that it packages well and then mostly have the emissions data.”

During this next phase, Williams said SWRI and its consortium members “will focus much more on the vehicle in terms of performance, towing and shifting.” Williams said. “We've got the new Allison, their 4000 Series automatic transmission. They're really eager to see what it does and how it feels.”

Interest among fleets has frequently turned to sales inquiries.

“Every show we've had the truck at we get asked, ‘Are you selling these? How soon can I get one?’” Williams said.

SWRI’s role in H2-ICE is to perform R&D with its consortium members and to educate fleets on the alternative fuel powertrain.

Though the engine is not the same as Cummins upcoming X15H, one of the bigger points of the build was to show how easily and quickly an existing engine could be converted to hydrogen.

The first phase took only 18 months from engine conversion to stellar emissions results in a Class 8 long haul truck.

“The big piece of it there is that it is still a mostly red [Cummins] engine,” Williams said. “A big part of our messaging is that 90% of the engine carries over and there's not a whole lot of specialized components that you need to run on hydrogen.”

For phase one, SWRI opted for 30 kg of hydrogen storage from a fellow consortium member which enables up to 300 miles of range. The institute explained that depending on interest, a larger system could be utilized in the second, upgraded round that would show a 600 to 700 mile range.

“Cummins will introduce a certified 700 bar type IV pressure vessel (AH620-70) to market in Q3 2024, enabling a weight and cost-optimized solution for North America heavy-duty trucks,” said Derek Kiesler, Cummins Global Fuel Delivery System Leader.

Critical role of fleets

As H2-ICE development progresses at major OEM suppliers like Cummins, Williams explained that SWRI hopes to bring additional awareness to the technology and sign-up fleets for the next phase of development.

The institute has planned to showcase its modified X15N hydrogen truck at trade shows including SAE International’s COMVEC. The truck was scheduled to be featured in-person during the event from September 10-12  in Schaumburg, Illinois. SAE billed the event as “the leading forum where global experts in the on-highway, off-highway and defense sectors collaborate in a neutral environment to find advanced solutions that will keep [commercial vehicles] reliable, sustainable and efficient.”

The opportunity includes a chance to observe and hear the truck’s engine. It is the only operational Class 8 H2-ICE demo truck featured at trade shows in the United States, according to Williams. Experts at Cummins have suggested an X15H will be available for vehicle demonstration in 2025.

SWRI is counting on fleet participation in the second phase of the consortium to help enable more effective R&D.

“It’s mostly the input and the exposure in terms of use case and what's most important to them. That's really what we're expecting from fleets,” Williams said. “Hopefully this serves as an opportunity for them to get some experience with these so that they can either advocate for it or get the message to the industry of where we're falling short or what else might be needed.”

From Cummins’ perspective, fleet involvement in the consortium is indeed a critical component in advancing H2-ICE.

“This really helps show the customer what the technology can do,” King said. “It starts verifying [capability] to the point that customers say, ‘I could see this in my fleet. It really is like the diesel truck I'm running today with all these other benefits of a zero-carbon fuel.’”

Consortium members like Cummins also benefit from SWRI’s efforts in H2-ICE.

“I think it aligns well with our Cummins HELM™ strategy where you can take a base technology and adapt it to the different fuel types,” King said. “In this case they're doing it to our engine and hydrogen. We all get to learn from that, which is fantastic.”