Will cleaner diesel trucks matter in ZEV world?

With that sort of scenario, it might be easy to view the DTF as the defender of the status quo. But it appears to be trying to get ahead on the issue and seeing the diesel sector as leading the charge to a cleaner future, albeit one that might not be clean enough for the Golden State and the states that have said they will follow California’s lead on the Clean Trucks and Clean Fleet rules, all or in part. (According to CARB, they are Connecticut, Colorado, Hawaii, Maine, Maryland, Massachusetts, New Jersey, New York, North Carolina, Oregon, Pennsylvania, Rhode Island, Vermont and Washington.)

The DTF recently came out with a study on the growing percentage of trucks, from Class 3 to Class 8, that are near-zero-emission vehicles (NZEVs), a term the DTF uses but one that might be scoffed at in California. In California, the goal is the zero-emission vehicle (ZEV) and it is all that will be allowed in the state in about 20 years, whether it is powered by batteries, hydrogen or something similar. Starting next year, only ZEVs will be able to be admitted to the state’s drayage registry for trucks that serve California’s ports.

The data released by the DTF on the NZEVs reported that the number of trucks that met that criteria was up slightly more than 10% between 2021 and 2022. The definition of those trucks is that they are manufactured after 2010, when such clean engine technologies like diesel exhaust fluid were introduced. 

But that broad figure is for everything from Class 3 on up. For Class 8 trucks, the DTF reported that 96.8% are NZEVs, 1.3% are running on compressed natural gas, 0.2% are electric and the remainder are gasoline or other fuels. 

In the truck ecosystem envisioned by the dual California rules, NZEVs don’t exist in that state. It’s a multistep gradual process to full ZEV compliance, which comes anywhere from 2036 onward into the 2040s depending on how the regulation is implemented. Regardless, the level of cleanliness coming out of a NZEV diesel engine isn’t in the plan. 

Schaeffer does not dismiss the California regulations out of hand. “California is California,” he said as a recent guest on the FreightWaves podcast Drilling Deep. “They’re always going to position themselves as the leader and solver of all problems and they’re definitely pushing and nudging the industry in this direction.”

Schaeffer noted that California is “pouring billions of dollars into starting all this up and we’ll see how well it works.” And he wasn’t dismissive of the chances of success. “It will work in some parts of California because of that financial investment.” 

As others have noted, the hindrance for clean truck adoption is not necessarily going to be under the hood. It’s going to be building out the distribution network of whatever becomes the prevalent fuel that powers the engine of the future, whether it’s batteries or hydrogen in a ZEV world, with clean diesel, renewable diesel or natural gas in parts of the country where ZEVs aren’t required. 

Another possibility is hydrogen. But even for that fuel, the precise adoption isn’t clear. It can be  combusted within ammonia, which creates nitrous oxide emissions, or injected into a fuel cell to create electricity that powers the same engine that would be driven by batteries. That would be considered a ZEV use.

“If you get away from California and start getting into America’s heartland, where some of these states are already ranking high in the adoption of advanced diesel trucks from our recent analysis, you have to wonder whether they’re going to have a supportive ecosystem and infrastructure,” Schaeffer said during his Drilling Deep appearance.

The agreement between the OEMs and CARB signed earlier this month, Schaeffer said, “raises some questions.”

The deal between the two parties does not slow the calendar for full ZEV adoption in California. But it did see CARB withdrawing its own regulations on NOx emissions, which called for stricter standards beginning next year, in favor of adopting the tighter federal standards that go into effect in 2027.

“I think California was out on a limb in terms of the timing of their NOx standards and some other provisions that just were not in line with the Clean Air Act,” Schaeffer said. States that have declared their intention to go along with what California intends to do through its Clean Truck and Clean Fleets rules will now find that on NOx, “California is not going to be different.”

The Schaeffer forecast is that “some of these sectors and places are going to go faster. And some of these sectors are going to stay using diesel for a very long time, because things are not going to go as fast as we thought they might, and they’re going to cost a lot more than we thought.”

In 2024, with no new internal combustion engines allowed into the drayage registry for California, it will mark the first significant step on that state’s path to a ZEV-only trucking sector. And with a certain percentage of existing vehicles aging out, the question will be how many ZEVs come into the drayage registry to replace those that age out.  

There are non-California incentives to drive the transition; the hydrogen community has been jubilant over tax incentives for green hydrogen production in the Inflation Reduction Act. “These are going to be helpful in kick starting things, but are they going to be able to drive the level of investment and decision-making outside the state of California to make this leap to zero emissions?” Schaeffer said. “I think the jury is still out on that. But some cities and some states are definitely going to get there.”

The size issue was raised by Schaeffer not just in geography but also in discussing the sweep of the trucking industry, in which megacarriers fight for the same business that can also be served by companies that are a fraction of their size, operating in just a handful of states.

“When you’re running multiple billion dollar public companies, you can dabble in some of these experiments and learn from them, but keep in mind that the majority of the trucking industry is fleets of 20 or fewer trucks,” he said.

On the West Coast, “where they are pouring big money into the infrastructure, it might be to your advantage to start to make a change.”

With the possible dichotomy between California and the rest of the country over NOx emissions now put to rest, Schaeffer said he foresees new technologies on NOx emissions introduced by OEMs as the 2027 deadline nears. 

Key target areas are cold starts and low loads. The 2010 rules did not address the NOx emissions that are produced during those sorts of conditions, but moving forward, “we’ve got to have very low NoX emissions during the whole time frame of operations for the truck,” he said.

Cold starts of the engine “comprise a significant amount of the operating time in some urban areas, so it’s important that these systems work at maximum potential, almost right off the bat when the truck gets moving.”

But Schaeffer expressed optimism that the goal could be met. “It’s pretty clear that manufacturers have a good understanding of how to do that,” he said.

California has strict rules on how long a vehicle can stay on the road. Vehicles with a model year prior to 2009 already have been taken off the road. A truck must be retired at the earlier of 18 years or 800,000 miles, or a minimum of 13 years if the truck has more than 800,000 miles. Those rules are not in place in other parts of the country, so there is no mandate that takes dirtier trucks off the road and replaces them with NZEV technology. But Schaeffer said the “general rule of thumb” is that trucks get retired after 12 to 15 years of service, which means the replacement of older vehicles with newer ones leads to a cleanup of the fleet even without California-type mandates.

With the national percentage of NZEVs rising 10% this year, Schaeffer said “it will be interesting to see what happens next year.” 

The NZEV data does not take into account whether the engine is burning renewable diesel, which Schaeffer said has limited impact on NOx emissions for an NZEV vehicle. “But for trucks that were built before 2010, we would see a greater benefit in NOx particulate mitigation from using renewable diesel or biodiesel fuels than the newest generation of trucks.” 

The primary benefit to the use of renewable diesel — which is a drop-in fuel that can be substituted for petroleum diesel on a 1:1 basis — comes in lower carbon emissions, Schaeffer noted.

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