The Southwest Texas Research Institute has successfully built a hydrogen internal combustion engine that can power a commercial truck completely carbon-free — however, getting hydrogen pumps installed around the state remains a major speed bump.
The nonprofit San Antonio-based research institute recently showed off its new hydrogen-fueled demonstration vehicle — a semi-truck with a converted combustion engine that produces low emissions while still providing enough power for a heavy-duty truck.
The 13-foot-tall bright blue tractor-trailer parked in front of the Tom Slick Cafe at SwRI’s annual meeting of advisory trustees and board of directors last month, decked out with the logos of sponsors that helped pay to develop the technology, and labeled with a large “H2” on the side.
Besides the SwRI sticker marking it, it could pass for a regular 18-wheeler.
Under its front-loaded hood, the engine is easily visible — with specially converted areas of the otherwise normal-looking combustion engine painted royal blue so they can be seen in demonstrations.
But while the high-tech, low-carbon, environmentally friendly truck is ready to hit the roads right now, America’s roads are hardly ready for the truck.
Barriers to scaling up hydrogen infrastructure are still abundant, namely the fact that hydrogen is not easy to store as a liquid, plus it’s highly flammable and overall lacks government support.
While SwRI’s hydrogen truck could theoretically travel about 500 miles without needing to refill, it would be difficult for it to find a fuel station on a trip to, say, Los Angeles.
Semi-trucks are significant contributors to transportation-related emissions, accounting for roughly 23% of the sector’s total emissions in the U.S.
Texas energy leaders are hopeful that the Lone Star State can lead a hydrogen revolution — starting now. Texas is already considered an energy leader in the world and already utilizes hydrogen. SwRI leaders are also hopeful, noting that Texas is often a large laboratory for energy innovation.
“We’re always trying to anticipate where problems are going to arise in the future, and develop solutions for those arising problems, whether they be in the government sector or the commercial sector,” said Adam Hamilton, president and CEO of SwRI.
The H2-ICE demo vehicle
For SwRI researchers, a working hydrogen engine has been years in the making.
Now, the research institute and its partners are trying to help solve the problem of how to build out more hydrogen infrastructure, such as safe, easy-to-access refueling stations.
In 2022, SwRI first launched the “H2-ICE consortium,” which brought together engine and truck manufacturers, fuel and lubricant providers and direct suppliers to help solve the problem according to SwRI. The consortium aims to show how H2-ICE vehicles can work alongside other zero-emission vehicle technologies (such as batteries).
To reach the group’s goals, it needed to build a hydrogen-powered engine that emitted very low nitrogen oxide (NOx) emissions, along with low carbon dioxide (CO2) emissions. Both emissions, given off when fossil fuels like gasoline or diesel are burned, contribute to smog — which is a harmful mixture of air pollutants that can make the air unhealthy to breathe.
In 2022 the H2-ICE consortium set an aggressive 18-month timeline to create such an engine for a semi-truck that was also compatible with California’s air standards — which are the strictest in the nation.
That’s because the team wanted the project to align with the Environmental Protection Agency’s Phase-3 greenhouse gas policy, which is part of a broader effort to reduce emissions from heavy-duty vehicles and engines, said Ryan Williams, a SwRI Powertrain Engineering Division manager and the H2-ICE consortium’s program manager.
The EPA’s Phase 3 focuses on establishing stricter standards for greenhouse gas emissions specifically for trucks and buses, although it’s unclear if these standards could be rolled back under the Trump Administration.
Last May, SwRI announced it had successfully built a demonstration vehicle with a functioning hydrogen engine for a semi-truck that fit these standards. SwRI scientists were able to convert a natural gas engine provided by Cummins to run on hydrogen, using components supplied by consortium members.
SwRI shared the feat as its top achievement of 2024 at the annual meeting in February. Altogether between the parts that were donated and the engineering effort, roughly $5 million was invested into the demonstration vehicle, Williams said.
“We’re now taking this around to trade shows and we want it to be obvious what’s going on inside of this,” Williams told the San Antonio Report while showcasing the vehicle and the converted engine.
While helping everyday Americans understand the possibilities created by hydrogen engines is important, helping policymakers understand them will be essential, he said: “I think the pace at which these engines are introduced into the public will be driven by policy.”
In December, SwRI announced a second consortium called H2HD REFUEL to tackle some of the barriers to refueling. Over the next four years, SwRI researchers will use hands-on experiments, system modeling and theoretical studies to better existing hydrogen refueling equipment and explore potential alternatives.
“We are pursuing and trying to recruit commercial clients to be members of the second consortium to advance that technology,” Hamilton said.
The state of hydrogen refueling
As of 2024, there are close to 60 open retail hydrogen stations in the United States, most of which are in California and Hawaii, according to the U.S. Department of Energy’s Alternative Fuels Data Center. The majority of the hydrogen refueling stations in Texas are privately owned, including one at SwRI.
One of the most difficult aspects of a hydrogen economy — a world in which hydrogen exists as a prominent source of fuel — is the fabrication and distribution of the fuel itself, said Michael Webber, professor of energy resources at the University of Texas at Austin and head of the Webber Energy Group.
Webber said he is currently working on a large project with Oak Ridge National Lab, GTI Energy, and several major oil and gas companies trying to figure out how to encourage the growth of the hydrogen market in the U.S.
Making standalone hydrogen tends to be “dirty,” Webber explained, noting that the typical forms of hydrogen production that exist today actually release a lot of carbon dioxide.
Finding cleaner ways to make the clean fuel is one of the major challenges facing the industry, he explained.
Making, moving and storing hydrogen in a fuel-ready way is not as easy as it is for gasoline or diesel, due to its extremely low density, meaning it takes up a large amount of space compared to the energy it contains.
“Gases like methane or hydrogen are harder because you have to compress them a lot or liquefy them and that takes a lot of energy,” Webber noted. “Then you can’t store it quite like gasoline, you need a bigger tank, so it’s also more expensive to store.”
That doesn’t really work for the average small vehicle in today’s market, Webber said, where electric vehicles will likely always outcompete hydrogen.
However, hydrogen is making a name for itself in the trucking industry as a possible alternative fuel to diesel, he said. Creating battery-powered semis is difficult because of the high torque semis need to run, and because drivers don’t want to have to be stopped for long periods of time for charging.
“These trucks drive hundreds of thousands of miles,” he said. “So on paper, hydrogen looks like a pretty good alternative.”
Hamilton agreed.
“It’s probably not good for the everyday consumer yet, because there are no retail filling stations — but for fleet delivery services, … it’s a great thing,” he told the San Antonio Report.
Texas as a leader
Asked what Texas can do to become a leader in hydrogen, Webber argued that the Lone Star State already is a leader for the alternative fuel.
“We already make and manufacture and use and pipe and store more hydrogen than the other state,” he noted. “We are maybe top 10 in the world — we have a pretty robust hydrogen sector, and that means we have ways to make hydrogen.”
Most of the state’s hydrogen is used for industrial processes like oil refining, fertilizer production, and metal treatment, however, not for driving vehicles, Webber explained. The question is if Texas will maintain its status as a hydrogen leader and spread hydrogen use to other sectors, such as vehicles.
Along with SwRI and Webber, several researchers in the state are already looking at how to do that, including University of Texas’ Michael Lewis. Last year Lewis helped author a report titled “A Framework for Hydrogen in Texas,” which looks specifically at what is needed to build out automotive hydrogen infrastructure in Texas.
The report’s authors created the “HoWDI model,” or Hydrogen Optimization with Deployment of Infrastructure economic optimization model. The model aims to help industry participants maximize their profit by balancing the benefits of using hydrogen in different areas with the costs of building and running the needed hydrogen infrastructure.
That includes everything from making hydrogen, getting it to where it’s needed, and delivering it for use.
The model shows how hydrogen is made and used in Texas at 23 hubs. It also tracks how hydrogen moves between these hubs via pipelines or trucks. The model helps business plan where to build systems to produce and deliver hydrogen to people.
According to the report, the next steps for Texas should be cost-driven. Hydrogen stations could be built first for trucks, which use a lot of fuel and need more range and faster refueling than battery electric vehicles.
Building stations near hydrogen pipelines, especially in the Gulf Coast region, would be smart — but there are other good spots for stations across Texas. Focusing on busy freight routes in the Texas Triangle —the economic center of Texas that exists between Houston, San Antonio and Dallas — could help create enough demand to support these stations and clean hydrogen production, the report explains.
“To lay the groundwork … an essential step is to engage in hydrogen energy outreach to Texas legislators and communities,” it states. “Without this engagement, policy actions and the build-out of new infrastructure could encounter delays or other hurdles.”
For the most part, support of a hydrogen economy in Texas seems bipartisan, Webber told the Report.
“There are a few things that seem to have bipartisan support right now — but nuclear and hydrogen and carbon management, carbon capture all seem to have some bipartisan support,” he said.
In 2023, the Texas Legislature established the Texas Hydrogen Production Policy Council to study and provide recommendations on the Railroad Commission of Texas’ policies for hydrogen energy development in the state.
Its report offered five recommendations to the legislature in December 2024, including maintaining current oversight and suggesting rule-making for hydrogen infrastructure be different from infrastructure requirements for other pipelines.
So far, no new bills related to hydrogen infrastructure have been filed yet during the current Texas legislative session, although Texas Hydrogen Day will take place on Wednesday, Mar. 19 at the Texas Capitol and could lead to some happenings on the issue in Austin.
Back in San Antonio, SwRI is laser-focused on the science of it all.
“SwRI is really a well-regarded entity to do this type of research, so I’m not surprised that they would have some advances on this,” Webber said. “I look forward to seeing what comes out of their efforts.”
