The climate crisis requires that we decarbonize our global transportation systems. To meet this requirement, the purported solution for some time has been "electrify everything."
Technical experts and the climate-concerned public alike have long pushed the idea that the future will be one of clean electricity that powers just about all aspects of our life. I bought in — at least for a time. It wasn’t until I began studying the details surrounding the challenges of putting a battery into a car, truck or container ship that I realized that things are much more complicated than ascribing to an aspirational motto.
To be clear, batteries probably will make great sense for certain elements of trucking. In fact, well-known companies in the electric vehicle space, such as Tesla, have a product on the horizon to address medium-haul, 300- to 500-mile operating ranges. However, specifically for long-haul routes, I argue there is a technology more suited to the task: the hydrogen fuel cell.
Fuel cell trucks use the same basic electric drivetrain as battery trucks (and even have a battery) but due to their on-board hydrogen storage, fuel cell trucks have a much longer range, require fewer stops on long routes, can be fueled much faster and have less risk of lost cargo capacity.
After fuel, labor is the costliest part of a trucking company’s budget.
Another major company, Daimler, is actively working with this drivetrain technology, currently testing a new product with operating ranges of 625 miles or more. In short, fuel cell trucks have many of the benefits of diesel, without the harmful emissions, provided the hydrogen production pathway can be effectively decarbonized.
This is true of the electricity needed for battery electric vehicles as well. Alongside developing new technology for the trucking sector, production pathways will need to drastically reduce GHG emissions in order for any changes in drivetrain to meet climate objectives.
The old aphorism that time is money is particularly true in the freight transport business. After fuel, labor is the costliest part of a trucking company’s budget. Missed delivery dates can also result in penalties to the company, depending on specific contract language.
As such, the first reason why much of the long-haul heavy trucking sector likely will be hydrogen fuel cell-based is due to time. A long-haul, Class 8 truck with a 100-kilogram hydrogen tank can be fueled about 15 times faster than charging a 1-2 megawatt-hour battery needed on the battery-electric equivalent. Cross-country drive times can take up to 35 percent less time due to decreased dwell time as well as the smaller number of stops required. This should make hydrogen fuel cell heavy trucks the more appealing option to businesses that are based around moving goods efficiently around the country.
The second reason is that vehicles powered by hydrogen fuel cells will have an edge on electric trucks comes down to cargo capacity. The 1-2 MWh battery required for a long-haul truck will be much heavier than a full tank of diesel or a fuel cell configuration, which typically only needs a small battery of 20-100 kilowatt-hours capacity to accompany the hydrogen.
My analysis shows that if you start with a maximum-weight 80,000 pound, Class 8 truck and assume a battery mass of 4 kg per kWh (something that has been achieved in passenger vehicles but is still unproven for the large batteries needed in heavy trucks and the cooling systems that go with them), a hydrogen fuel cell vehicle loses about 1,000 pounds of cargo capacity whereas a battery-electric vehicle potentially would lose around 5,000 pounds, compared to diesel trucks of today.
Furthermore, if we can’t get to a 4 kg per kWh relatively soon, we can expect larger cargo capacity losses of 10,000-15,000 pounds in the short term with the battery-electric configuration.
The smaller battery used in the hydrogen fuel cell configuration also would weigh more in this case, but even in the worst-case scenario, a vehicle using one would only lose about 2,000 pounds of cargo capacity, according to my analysis.
All told, on average, businesses using hydrogen fuel cell trucks will enjoy all of the benefits of reduced emissions, without sacrificing much of the cargo space they need. In fact, their carrying capacity would be comparable to current diesel fleets.
The third reason hydrogen fuel cells may make more sense for the long-haul trucking business is flexibility. Hydrogen fuel cell vehicles have more range than their electric counterparts — they are expected to reach twice the number of miles per full charge/tank.
An all-electric fleet could handle many regional loads, running along a spoke to and from a hub, but a hydrogen fuel cell vehicle could handle regional delivery as well as cover longer routes with little time needed for refueling. A more flexible fleet is one that may earn more for the business.
Finally, total cost of ownership (TCO) is lower for hydrogen fuel cell trucks. Although the price of hydrogen and somewhat lower efficiency compared to battery-electric trucks could lead to elevated relative fuel costs for the hydrogen fuel cell configuration, preliminary analysis by the National Renewable Energy Laboratory (NREL) concludes that a battery-electric, long-haul heavy truck will have a higher TCO than its hydrogen counterpart. This is primarily due to the capital expense of a larger battery.
The battery-electric vehicle also has a longer average stop time — used to charge as mentioned above — which costs money. Put together, NREL concludes that the TCO for a hydrogen fuel cell long-haul truck (multi-shift, weight-limited class 8 sleeper) is 15-25 percent lower in 2025 than a battery-electric truck. Given its impact on shipping costs, TCO is one of the most important parameters for freight businesses and end-users alike, making hydrogen fuel cell an attractive choice.
It’s also worth noting that the potential advantages of hydrogen fuel cell heavy trucks are not limited to the merits of individual truck performance or cost. Some back-of-the-envelope analysis has shown that the required infrastructure buildout to support an all-electric heavy truck fleet would need to be very robust in terms of charging station size, number and power requirements.
Specifically, the electric infrastructure required for large charging stations for long-haul trucks may be 20-25 MW each. Compared to diesel, you may need to give these stations three to four times more space or build them to a similar size but in around eight times the number of locations. On the other hand, the equivalent infrastructure for hydrogen would have a similar footprint to diesel, although the stations would be more expensive and complex.
A long-haul, Class 8 truck with a 100-kilogram hydrogen tank can be fueled about 15 times faster than charging a 1-2 megawatt-hour battery needed on the battery-electric equivalent.
Now, there are some applications where it does make sense to use battery electric trucks over their hydrogen fuel cell counterparts. For shorter trips, say 400-mile roundtrip regional delivery or for smaller trucks, the TCO for a battery-electric truck compares well to hydrogen fuel cell vehicles.
Charging infrastructure is also more developed, cheaper and less complex than hydrogen fueling stations, and the technology readiness level (TRL) is higher for electric drivetrains because the technology has been on the market for longer.
However, for long-haul heavy truck operation — something that in the U.S. still makes up 40 percent of truck routes, consumes 75 percent of all diesel fuel used by the trucking sector (29 billion gallons of diesel, 3.9 quads) and accounts for roughly 17 percent of transportation GHG emissions, or 330 million tonnes of CO2 per year — the future probably includes a lot of hydrogen.
As I see it, now is not the time to select a single transportation energy source.
For trucking, it appears that hydrogen will have some significant advantages, so let’s get busy building that infrastructure in key regions and along key routes. At the same time, let’s develop high-power charging stations that can support battery-electric heavy trucks and allow for high-speed charging to reduce stop times.
In short, instead of forcing everything to electrify or everything to use your fuel of choice, let’s develop the necessary technology and infrastructure — then use it for the appropriate application. That includes taking advantage of the merits of hydrogen for long-haul heavy trucking operation. In so doing, we can accelerate the proliferation of clean energy in the transportation sector, helping to achieve our climate goals and secure our future.
Analysis performed using the publicly available NREL tool FASTSim. In addition to the citations noted in text, vehicle and infrastructure parameters were based on discussions with NREL as well as referencing the following sources:
- Renewables in Transport 2050, FVV, 2016; Section 126.96.36.199
- Comparison of hydrogen and battery electric trucks, Transport & Environment, 2020; Section 1
- Why Regional and Long-Haul Trucks are Primed for Electrification Now, Lawrence Berkeley National Laboratory; 2021, Page 18-25
- Hydrogen Roadmap Europe, FCH; 2019, Exhibit 11