Battery-electric vehicles have a place in the journey to slash emissions, but speakers who opened the annual Green Truck Summit are casting doubt on the technology’s widespread viability in vocational and longhaul trucks.
Borrowing a phrase from the North American Council for Freight Efficiency (NACFE), this will mean a “messy middle” that requires a range of power options — from natural gas, to hydrogen fuel cells, and even further enhanced diesel engines in the name of cleaner air.
“We’ll continue to invest in a range of different technologies – including decarbonizing our engine-based solutions,” stressed Cummins CEO and president Jennifer Rumsey, citing the trucking industry’s diverse power, range, and operational needs. “Many different solutions will coexist depending on the application and depending on the region of the world.”
“We really see that 2030 timeframe as being a tipping point where you’ll see an acceleration of some of these alternative technologies. That depends, though, on these incentives, and infrastructure build-out,” she said.
Limits to battery gains
Giorgio Rizzoni, director of the Ohio State University Center for Automotive Research, acknowledged that today’s spending on research and development is heavily skewed toward zero-emission vehicles. “Maybe what we should really be thinking of doing,” he said, “is a broad range of solutions of which electrification is one.”
Battery costs have dropped as low as $200 per kilowatt-hour compared to $1,000 just over a decade ago, while battery capacity and durability have improved. But there are limits, Rizzoni said. “I think we’re reaching that [point of] incremental change. I don’t think that we’re going to see dramatic change.”
Solid state batteries won’t be a commercial option for awhile, and fast chargers degrade battery life, he said. Those developing medium- and heavy-duty work trucks also face an array of duty cycles that can’t take advantage of “off-the-shelf” battery systems, motors and power electronics found in many early electric powertrains. Their makers can’t take advantage of Toyota- and GM-like production volumes, either.
“It is still a lot to ask for a longhaul truck,” Rizzoni said of battery-electric power, referring to challenges such as battery size and weight. “I wouldn’t place a bet on megawatt charging being an answer … I personally think if we could solve the hydrogen supply infrastructure and refueling, I think from a payload perspective or payload cost that would perhaps be a better answer.”
Cold weather challenges
Cold weather can pour cold water on some battery-electric vehicle applications as well.
The average energy an electric truck consumes per mile increases “significantly” in cold weather, Rizzoni said. “Batteries are happy whenever you, the human being, feel comfortable.”
Andrew Wrobel, director – auto and mobility at Escalent, pointed to another challenge that can come in winter months. Recent ice storms and snowstorms have led to power outages. “There’s certain use cases where we need vehicles to work 100% of the time,” he said.
And while refuse and recycling trucks support electrification because of predictable ranges and routes, some of the units serve double duty as snowplows. When that happens, they need to work around the clock, he added.
“You’re not going to get the full usage out of it unless you have the DC fast charging that’s 800-volt, and you can charge it in 15 minutes, but then you have battery degradation issues.”
Even trucks supporting construction and trades could face challenges in colder weather when they suddenly can’t reach the outer limits of their summertime operating ranges, Wrobel said.
“The future powertrain growth will be very use case driven. It’s going to depend on how the vehicle is used, who’s using the vehicle, that’s really going to determine what powertrain strategy they use moving forward.”
When the batteries don’t fit
Then there’s a matter of even getting batteries to fit into available spaces.
Trucks with short wheelbases introduce packaging constraints, as do complex vehicle upfits. “Most of the small trucks we see out there are 60- to 84-inch cab-to-axle lengths. These trucks are going to have the hardest time, especially if they’re four-wheel drive,” Wrobel said, referring to examples where batteries might not fit neatly between a truck’s frame rails. Then there are the Class 4-5 dump trucks that require space for dump mechanisms and ePTOs.
Those who can get motors and batteries to fit will see maintenance savings, and equipment purchase prices will drop, Wrobel acknowledged. But the overall decision also needs to consider whether the trucks will support the job that needs to be done, he said.
Emissions from wells to wheels
The electrical energy that is produced is greener than it once was, though.
In 2021, about 35% of the energy used in the U.S. came from petroleum, with 25% from natural gas and 20% from coal, Rizzoni said. And almost half the electricity was generated by coal-fired plants. A decade later, natural gas has supplanted coal, while wind and solar power has increased by a factor of 10. They’re still small percentages — but represent a share of a massive market.
So, too, are there other opportunities to produce hydrogen. That fuel could be a byproduct of nuclear power plants, whether it comes from the generated energy or the thermal conditions, Rizzoni said.
“If there is a way to continue to find cost-effective ways of producing biofuels, that has to be part of the solution, and compressed natural gas continues to be a viable solution,” he added. “We need to look at all of these things.”
No matter how the energy is produced, there are also opportunities to improve how effectively it’s put to work.
Almost 65% of all the energy that the U.S. consumes is rejected because of efficiency losses, Rizzoni said, referring to a truth that applies everywhere from power generation plants to school buses, trucks, and buildings.
“What works for your use case is going to change over time,” Wrobel said. “Focus on what’s available now and what works for your use case.”