Sep. 6—Diesel engines have been the norm for heavy-duty long-haul trucks since the mid-20th century.
But the black smoke belching from the big rigs has become a growing concern as research shows diesel pollution is bad both for public health and the warming climate.
Some Los Alamos National Laboratory researchers are working on a technology to clear this noxious pollutant from the roadways.
The lab is part of a consortium working to develop hydrogen fuel cells that would work well on big trucks and eventually replace the diesel-burning engines.
A lab researcher said the work could revolutionize the trucking industry.
"Really, the time to get [hydrogen fuel] trucks out on the road is now," said Rod Borup, lab scientist and fuel cell program manager.
The project is dubbed "the million-mile fuel cell truck," with the goal of developing a technology that can be marketed to the industry in the not-so-distant future.
The consortium working on the project is made up of several national laboratories and the Office of Energy Efficiency and Renewable Energy, a branch within the U.S. Department of Energy.
The lab also has a broad mix of public and corporate partners tied to its fuel cell research, including Ford and General Motors, 3M, Advent Technologies, Georgia Tech, the University of Tennessee and some startup companies.
Hydrogen is a clean-energy alternative that aligns with state and federal goals for sharply reducing greenhouse gases, Borup said, noting the only byproduct these engines release is water.
The transportation sector burned 44.6 billion gallons of diesel in 2020, according to U.S. Energy Information Administration data, which includes all users of the fuel, not just the trucking industry.
Gov. Michelle Lujan Grisham's 2019 executive order sets a 2030 target for cutting the state's greenhouse gases by 40 percent. Earlier this year, President Joe Biden signed an executive order calling for half of U.S. vehicles to have zero emissions by 2030.
More miles, less pollution
The consortium's goal is to create a fuel cell for the trucks that will last about 30,000 driving hours, or roughly 1 million miles — hence the project's name, Borup said.
The lab has worked to develop fuel cells, which can produce electricity, since the late 1970s. A few years ago, Los Alamos changed the focus of its hydrogen fuel cell research to long-haul trucks when companies such as Toyota and Hyundai made headway on building and selling hydrogen cars, Borup said.
"We're just really shifting from light-duty vehicles to heavy-duty vehicles because we think that's what's really needed now," Borup said.
Marketing fuel cells has less to do with sticker price than the long-term value — or how much mileage a trucker will get from the investment, he said, which is why durability is key.
Researchers are developing high-temperature "proton exchange membrane fuel cells," which convert hydrogen and other renewable fuels into electricity.
Traditional fuel cells run at a cooler temperature, giving them a low tolerance to fuel impurities, Borup said. And it's actually harder to remove excess heat from a cooler-running system, he added.
The lab has been tasked with creating accelerated stress tests on the components so it can determine whether they will last for 30,000 hours, Borup said. It's also developing some of the materials for the cells, he said.
Improving this and other technologies for big trucks will aid the industry in shifting toward zero emissions, Borup said.
An environmental advocate said diesel fumes should be eliminated as swiftly as possible. It would not only combat climate change but improve air quality, especially in communities near highways, said Patricio Portillo, traffic analyst and clean fuel advocate at the Natural Resources Defense Council.
Burning diesel creates nitrogen oxide and particulate matter, both of which can cause or worsen respiratory and heart problems, Portillo said. Prolonged exposure to high doses of diesel smoke also can cause cancer, strokes and impaired brain development in children.
Although there are fewer big rigs on the road than cars, they are driven much more and, in turn, spew more exhaust, Portillo said.
Diesel pollution has a disproportionate effect on poor neighborhoods, which tend to be the ones near freeways and warehouses where commercial trucks go, he added.
New technology is only part of the solution, and must be paired with strong regulation that leads to the cleaner transportation being available and encouraged, Portillo said.
The council has a neutral stance on green fuels, backing whatever works best on particular vehicles, Portillo said.
However, when it comes to hydrogen, his group would prefer it be produced using renewable energy rather than natural gas, which would diminish its value in reducing emissions, he said. He said electric generation plants also use natural gas, but many states, including New Mexico, are moving toward having renewable energy power these plants.
In New Mexico, where solar and wind power is burgeoning, the state requires half of the electricity from investor-owned utilities come from renewables by 2030 and 100 percent by 2045, Portillo said.
In general, electric batteries seem better to replace diesel motors on delivery vans, buses, garbage trucks and other vehicles that stop and go, Portillo said.
"The heavy duty ones that are driving long distances — those might be perfect for the hydrogen application," he said.
Battery-powered electric cars are another prime technology for reaching zero-emission goals.
These cars have overshadowed hydrogen vehicles because people can charge the batteries at home. But no one has hydrogen fuel tanks sitting around, Borup said.
Infrastructure in general is a challenge for hydrogen, he said.
For that reason, hydrogen is better suited at the moment for heavy-duty trucks because as long-distance carriers, they don't require nearly as many fueling stations as the 350 million U.S. cars cruising around in smaller areas, he said.
Charging the battery on a big rig could take a couple of hours, whereas the fill-up time for hydrogen is similar to that of current fuels, Borup said.
Another problem with electric batteries is their size and weight, which on long-haul trucks could add up to almost a third of the load, he said, citing a study presented at a California Hydrogen Business Council webinar in 2020.
"As you go to heavier and heavier [vehicles], and bigger and longer driving distances, fuel cells have an even bigger advantage over batteries," he said.
But one group that is pushing for reduced vehicle pollution believes electric batteries are the best option for the trucking industry.
"I think the math and practicality of it points to electricity," said Travis Madsen, transportation program director for the Southwest Energy Efficiency Project.
Power generation plants and transmission lines are already in place, and major utilities in the state have agreed to install charging stations for electric vehicles, Madsen said.
With hydrogen, the supply chain, filling stations and pipelines must be built almost from scratch — and will cost a colossal amount of money, he said. For that reason, he thinks it ultimately will be relegated to powering ships, trains or trucks in areas where there's no electricity.
Batteries also are more efficient, losing very little of their energy, whereas hydrogen fuel cells only have about 60 percent efficiency due to surplus heat generated, Madsen said.
Electric vehicles cost less to maintain and recharge, Madsen said, adding hydrogen fuel is now expensive.
The Energy Department reports hydrogen made using renewable energy costs $5 a kilogram or roughly $10 a gallon. Suppliers have said they will work to bring the price down when sales pick up.
The main advantages for hydrogen are quicker refueling time and the fuel tanks weighing less than batteries, Madsen said.
However, he disagreed with the 30 percent payload that Borup cited, noting a report by the International Council on Clean Transportation estimates a larger battery makes up only 11 percent of a fully loaded truck's weight.
The cost savings will offset what individual trucks lose in freight capacity, Madsen argued.
Johnny Johnson, managing director of the New Mexico Trucking Association, said the battery's weight would be a sticking point for the industry adopting electric vehicles.
In contrast, the hydrogen fuel cells are lessening the truck's weight, Johnson said, "so in that regard, I think it's an advantage."
The industry would be open to any new technology that reduces costs and increases efficiency, Johnson said.
The main problem with hydrogen is the lack of infrastructure, he said.
"Until you have the infrastructure ... it's not practical," Johnson said.
Borup said the lab is pursuing hydrogen fuel cells for big trucks partly because it seems the best avenue to establish a wider supply chain, including for cars, buses and other forms of transportation.
"We're looking at that as a way to ramp up the hydrogen infrastructure," Borup said.