Moving 80,000 pounds is no easy task. It is normally reserved for semi trucks equipped with large diesel engines producing thousands of pound-feet of torque. Yet, the automaker known for the Prius is taking on the job with a unique fuel solution–hydrogen. We traveled to the hot, dry desert surrounding Toyota’s proving grounds to see how this water-based fuel system works in a Class 8 semi.
Toyota’s “Project Portal” is a zero-emission Hydrogen fuel cell truck capable of hauling the massive 80,000-lb load up to 200 miles. It is a “proof of concept” vehicle that was built in just 8 months–a ridiculously fast timeframe for the conservative company.
How Does it Work?
With its hood open, it is easy to see why development was so quick. Toyota quite literally took two of the powertrains for its Mirai hydrogen fuel-cell car and swapped them into a Kenworth T680.
Engineers started by removing both the massive diesel engine and the 18-speed transmission. Then, a rather small electric drivetrain, barely filling the engine bay, was put in place along with a drive-by-wire transmission and two axle-mounted motors that generate 1,325 lb-ft of torque and the electrical equivalent of 675 hp. This is nearly the same power output of the 10.8-liter diesel normally used in the Kenworth.
Inside the sleeper cab, Toyota mounted two hydrogen fuel cell tanks side by side.
“These are semi-custom tanks bought from a supplier,” says Georgio Zoia, Toyota Senior Project Manager. “It is a translation of the tanks for CNG. Each is almost double the size of a Mirai tank.”
On the driver’s side sits an inlet that resembles a natural gas connection through which the tanks are refilled. Zoia says refueling takes about 30 minutes, similar to the time needed to refill a 250-gallon tank on a diesel truck, and can be improved with “chiller” to keep the Hydrogen cooler. As Boyle’s law tells us, the cooler the tank, the faster it can be filled.
Also, the range of the truck is only limited by the size of the tanks. Right now, Toyota is demonstrating the vehicle with just the two tanks, but could add more to increase the range—say, for long-haul trucking applications.
Behind the wheel, Toyota engineers installed the multi-function display from the Mirai where the radio would normally go. They also replaced the long-handle shifter for the 18-speed gearbox with the Mirai’s shift knob, which looks comically small inside the large cabin.
On the Road
Starting the truck is as simple as pushing a button. The first sounds come from the on-board air compressor, which provides both much needed air conditioning relief from the 112-degree temps as well as power for the air brakes. Once the compressor kicks off, the truck is whisper quiet. Putting the truck into reverse and releasing the brake causes it to it simply roll backward like a giant electric golf cart.
Once on the road, the truck quickly gets up to speed without the herky-jerky motion associated with many big rigs. Power is smooth and delivery feels effortless—it was quite an incredible experience.
Pulling up to a stop sign, the only sounds are of the air brakes and the creaking from the Kenworth chassis. Normally, the loud diesel engine hides these creaking sounds, but without its noise and vibration, it is quite clear just how much noise the truck makes on its own.
Before our time on the track comes to an end, we head over to a quarter-mile section to test its acceleration capability. While the 0-60 mph metric is largely ignored by the trucking industry, it is an interesting experience in the 18,000-pound-plus truck.
Putting the accelerator to the floor, we are physically flung back into our seats and remain so throughout the duration of the quarter mile. No jerking. No shifting. No engine delay. Instead, it is like a golf cart on steroids with immediate power on demand and smooth operation. Incredibly, the rig returns a 7.0 second 0-60 mph time.
Adaptability is the Big Deal
One of the exciting things about Toyota’s Project Portal is its adaptability.
“The way the system is designed, it runs off hydrogen fuel cells and the battery is a boost,” Rovick says. “Other ways you would see companies do it is with larger batteries and they would run it off the battery side of the powertrain, then the hydrogen is refilling the battery.”
Our system is to keep the battery as small as possible and really show the scalability of the fuel cell itself. The fuel cell is providing all of that power.”
The use of a smaller battery and versatile fuel cells that can be built in any size and shape deemed necessary, this powertrain is easily adaptable for a variety of different vehicle applications.
Is Fuel Economy Improved?
While reducing emissions is good, improved fuel economy is the real economic benefit and could be the driving force to widespread adoption. Currently, there is no data available from Toyota as it is still testing the truck;,however, if you compare the Mirai with a comparable-sized vehicle like a Camry, you can derive some conclusions.
The Mirai has a combined fuel economy rating equivalent to 66 miles per gallon. The 2018 Toyota Camry with the four-cylinder engine? Thirty-four miles per gallon combined, just slightly over half of the Mirai’s. While the duty cycle for a semi-truck is completely different from that of a passenger car, it’s not unreasonable to expect the fuel-cell semi to see better fuel economy than a diesel truck thanks to the system’s lighter weight and increased efficiency.
An additional financial benefit for fleet owners is reduced maintenance costs. Like other electric vehicles, this truck does not have any of the typical powertrain consumable needs like fluids, and there are fewer mechanical parts to break.
Why do Fuel Cells Make Sense?
Hydrogen fuel cells are nothing new; the first modern fuel cell was used in a modified Allis-Chalmers farm tractor around 1959. Yet, besides one-off demonstration vehicles and small test fleets, they only started reaching the mass market following the launch of the aforementioned Mirai, as well as the Honda Clarity Fuel Cell, both of which are offered in limited quantities. Zoia says this is likely to change.
“Fuel cells used to be really expensive due to the platinum metal for hydrogen to go through the membrane,” Zoia said. “Now, those materials are being changed and the quantity of expensive materials is going lower. There is even thinking that we may not even need platinum.”
Also, infrastructure is being built up, especially in California, and the continual development of new vehicles with this fuel type should spur growth.
Is Hydrogen Really Better for the Environment?
One of the issues you will always run into with alternative fuel vehicles is whether their production is more environmentally damaging than what is saved emissions. This is a problem with hydrogen since its production can generate considerable CO2 emissions.
“If you make hydrogen from a coal plant it produces a lot of CO2,” Zoia says. “However if you produce Hydrogen from electrolysis through wind power, it is has zero CO2. The main production of Hydrogen is from natural gas that they use to make gasoline. Natural gas is a pretty clean way of making Hydrogen.”
Zoia also says you can make Hydrogen from a variety of power sources like solar, land fill emissions, wind, natural gas, and coal. As the need for Hydrogen expands, so too could the way it is produced, meaning we could eventually have many clean sources of the fuel.
Finally, since the production of Hydrogen is where the CO2 is emitted from, pollution would be localized. Unlike gasoline and diesel vehicles, hydrogen fuel cell vehicles only emit water, which simply evaporates in the atmosphere. However, hydrogen is not without its own hazards—the gas is highly flammable, especially when pressurized (think Hindenburg disaster), and large-scale adoption could negatively impact the ozone layer, depending on how much is released into the atmosphere as part of the production, transportation, and storage process, either due to leaks or accidents.
Toyota has been at the forefront of hydrogen fuel cell development in automotive, and with good reason. Hydrogen provides the power-on-demand benefits of an electric car, exceptional range, and the refueling capability of a gasoline model. Also, it is adaptable for a variety of applications. If Toyota can make “Project Portal” successful, the potential for hydrogen fuel cell powertrains will open up greatly