As states and countries tighten environmental regulations, Kenworth Truck Co. is focusing a large part of its research and development on figuring out how make cost-effective trucks that can use less-polluting alternative fuels to haul freight.
Kenworth, a division of Paccar Inc. and sister brand to Peterbilt and DAF, wants to match or exceed the performance of diesel-powered trucks without the pollution.
Brian Lindgren, Kenworth’s R&D director, recently updated Trucks.com on what his team is working on. Lindgren also spelled out some of the challenges facing truck makers like Kenworth that are trying to meet the growing regulatory demand for zero-emission freight trucks.
Here is an edited version of the discussion.
How important are alternative-fuel powered trucks in Kenworth Truck Co.’s R&D efforts?
Alternative power is a large part of Kenworth’s current R&D efforts. Specifically, we’re working to develop trucks that have the capability to haul freight while producing zero emissions. We believe that zero-emission trucks will be required for operation in certain areas, first in California, then elsewhere. , We need to be ready with competent, commercially viable trucks that will be good business tools for our customers. We also know it will take years to achieve our durability, reliability and cost targets, and we’re already making good progress.
These trucks rely on electric power, regardless whether that power comes from the grid, an on-board generator, a fuel cell or a battery, so we’re developing electrified powertrains that are agnostic to the source of the electricity. By doing the integration of these systems in-house, we’re learning all the details that we’ll have to understand before we can build such trucks in production quantities.
Kenworth’s T680 hydrogen fuel cell truck will begin testing with Total Transportation Services Inc. at Southern California’s ports. How will you work with TTSI to evaluate the results?
Having TTSI run the Kenworth T680 Zero Emission Cargo Transport (ZECT) truck in real commercial operations will be hugely beneficial. The truck is fitted with telematics, so we can examine data on all aspects of the truck, from driver requests for more power to shift quality, to details on what is happening inside each of the cooling systems. We can simulate much of this on our computers and at the test track, but it’s imperative that we have real-world conditions to validate our models.
It is important to note that our Kenworth ZECT truck project is funded in part by the Office of Energy Efficiency and Renewable Energy, the U.S. Department of Energy and the South Coast Air Quality Management District.
Some drivers fear of hydrogen tanks might explode in a crash. Are they safe?
Hydrogen is generally considered to be as safe or even safer than other flammable fuels. Any compressed fluid, even air, requires precautions to ensure safety. We use tanks that are wound with carbon fiber for high strength and durability. Our current on-board fuel storage system uses six tanks, and if any one of them loses pressure unexpectedly, that tank is instantly isolated from the rest of the system, so only that one tank’s fuel is lost.
If a tank were to be punctured somehow, any hydrogen that leaks out will disperse very rapidly. Unlike gasoline, which can pool on the ground as a liquid and then turn to vapor at temperatures as low as 40 degrees below zero, and can ignite at 500 degrees, hydrogen just wants to get up and away — fast. Hydrogen is 13 times lighter than air, so it races up into the atmosphere away from the scene of the accident. The auto-ignition temperature is over 900 degrees, so it’s harder to ignite than gasoline.
What about during the hydrogen fueling process?
The fueling process includes a system that communicates between the truck and the fueling equipment to ensure that all connections are secure before starting the flow of hydrogen into the tanks, and then it monitors the pressure in the truck’s tanks during the entire fueling process.
And the fuel system isn’t the only area where we’re taking precautions. Our batteries and our traction motors run at 650 volts. Our battery sub-packs each has its own enclosure. Then we place these inside another enclosure and position them away from likely impact. We have even taken care to locate all of the battery electrical connection facing inboard inside the enclosure to minimize damage, accidental impact or unintentional disconnection. And we’ve incorporated interlock loops in the high-voltage circuits that power down the high-voltage system if a connector is unplugged or damaged, or if a cable is severed.
What must happen for volume production of hydrogen fuel cell and alternative fuel trucks?
We’ve shown that we can make these trucks work, but now we have a lot of work to do before we can take these concepts to series production. Diesel powertrains, along with the accessories such as engine-driven air compressors and power steering pumps, have had decades of continuous improvement to reach their current status. Electric ones, though, are still in their infancy. There still is a lot of work to be done to develop, integrate, tool and validate truck-specific components that can achieve the reliability, durability and cost expectations of our customers.
How does the weight of batteries, fuel cells and other components affect truck performance?
We’ve got plenty of acceleration and hill-climbing capability, but the real impact to performance is in payload capacity: 2,000 pounds added to the tare weight means 2,000 pounds of cargo you can’t carry. We’re working with the fuel cell suppliers to increase the power capability, which means we’ll be able to reduce the battery size. And ZECT is our first fuel cell truck — as a proof-of-concept prototype it’s probably over-built. There are opportunities to reduce weight as we improve our power electronics, accessory drives and cooling systems.
Paccar and Kenworth exhibited at the Consumer Electronics Show in Las Vegas this year. Will you be back?
We’re making tentative plans to be at CES again in 2019, but you’ll have to wait to see what we show this time.
What’s next for Kenworth’s R&D efforts?
We already have funding approved to develop four more CNG-powered hybrid electric trucks. These are zero-emission capable for 30 to 40 miles, and run at near-zero emissions beyond that. This project allows us to take our electrified powertrain and accessories one more step closer to production design. And then we’re putting together a project which, if approved and funded, would build a small fleet of hydrogen fuel cell trucks capable of regional haul applications in addition to port drayage.
Meanwhile, we continue to work on [advanced driver assistance systems] projects, as well as improving our diesel-powered products through advanced controls and aerodynamic improvements.