On October 8 (10/08) – symbolic of hydrogen’s atomic weight (1.008) — the hydrogen and fuel cell community celebrated the 4th Annual National Hydrogen and Fuel Cell Day. Officially designated by both the House and Senate, October 8 is a reminder of the environmental and economic benefits that can be delivered to America through large-scale use of hydrogen and fuel cell technologies. Included in this recognition are hydrogen fuel cell vehicles (FCVs), which are already emerging as commercial products in the gasoline-dominated light-duty sector. However, FCVs may hold even greater promise for their potential to displace diesel fuel in high-impact, high-fuel-use heavy-duty vehicle sectors. This will deliver the largest transportation-related reductions for both smog-forming and climate-changing emissions.
Conventional heavy-duty diesel engines have long dominated America’s heavy-duty vehicle (HDV) sector. However, an array of zero-emission (ZE) and near-zero-emission (NZE) fuel-technology platforms are beginning to emerge, and gradually penetrate into commercial sales. These include HDVs powered by natural gas, battery electric, propane, and hydrogen fuel cell technologies. Major progress is being made, but commercial products (so far) are quite limited. In particular, no ZE platform (battery-electric or fuel cell) is yet proven in the most-challenging Class 8 heavy-duty trucking applications.
Some experts believe this particular fuel-technology platform may offer the long-term ZE solution for high-fuel-use in heavy-duty trucking applications.
Although hydrogen fuel cell technology lags behind battery-electric in progress towards wide-scale use for class 8 heavy-duty trucks, it is nonetheless beginning to emerge as a promising solution. In fact, some experts believe this particular fuel-technology platform may offer the long-term ZE solution for high-fuel-use in heavy-duty trucking applications, because of advantages it offers on driving range and refueling time.
However, there are formidable challenges that must be addressed before hydrogen fuel cells are likely to begin significantly displacing diesel engines in America’s heavy-duty trucking sector. The biggest challenges relate to the current lack of hydrogen fueling stations, the high costs of heavy-duty fuel cell vehicles (largely due to expensive on-board hydrogen storage systems), and the high cost of the hydrogen fuel itself.
Lessons from the Light-Duty Market
By contrast, light-duty fuel cell vehicles are now in an early stage of commercialization. Passenger vehicles powered by proton exchange member fuel cells (which make power electrochemically by reacting hydrogen with oxygen from ambient air) are already on the market. These include the Toyota Mirai and Honda Clarity. Other major light-duty manufacturers have announced FCVs that will be available in the coming months and years, such as the Audi h-tron quattro concept and Hyundai’s 4th generation NEXO.
A perceived advantage of FCVs is that they are refueled in similar fashion to internal combustion engine (ICE) vehicles.
As consumer awareness regarding environmental issues continues to grow, light-duty FCVs are a promising solution. A perceived advantage of FCVs is that they are refueled in similar fashion to internal combustion engine (ICE) vehicles, whereas the nature of recharging battery electric cars requires changes in refueling procedures that have existed for decades. The advent of light-duty FCV sales by major OEMs has started to spur the build out of hydrogen fueling stations in America, but only about 50 stations will be operational in the U.S. by the end of 2019. The large majority of these are being built in California. Notably, almost none of the existing or near-term-planned hydrogen fueling stations can accommodate heavy-duty fuel cell trucks.
Benefits of Hydrogen Fuel Cell Technology for Trucks
Like batteries, fuel cells provide high-efficiency, electrochemical conversion of energy into motive power. Being combustion-free, this process produces zero direct emissions of harmful pollutants (including CO2). But, unlike batteries, hydrogen is stored in rapidly refillable onboard tanks, similar to the process for conventional diesel trucks. The net result is the same zero-emission performance as a battery-electric truck, while also providing range and refueling time roughly on par with a conventional diesel truck. This is especially beneficial for meeting the driving range needs of heavy-duty applications like regional and line haul trucking. The upshot is that heavy-duty fuel cell vehicles – hybridized with battery-electric architectures that improve performance and enable regenerative braking – can provide fleets with greater utility and applicability compared to “pure” battery-electric trucks.
Fuel cell technology is becoming increasingly mature and optimized for HDV applications.
Fuel cell technology is becoming increasingly mature and optimized for HDV applications. Today, it is the hydrogen fuel rather than fuel cell hardware that mostly entails the major remaining challenges for heavy-duty FCVs. In essence, hydrogen fuel presents the most-promising and most-challenging aspects of moving heavy-duty FCVs towards actual commercialization and broad use to displace diesel HDVs.
Exciting Developments for MD and HD Sectors
In contrast to the light-duty sector, medium- and heavy-duty fuel cell vehicles are further behind in the commercialization and technological maturity curve. Currently, none of the major truck manufacturers are offering an integrated fuel cell platform. That said, the future of fuel cells for commercial trucking looks bright. This is evidenced by recent announcements from OEMs that are launching major research and development efforts, coupled with demonstration projects.
The future of fuel cells for commercial trucking looks bright. This is evidenced by recent announcements from OEMs
For example, since mid-2017 Toyota has been testing a prototype Class 8 tractor powered by hydrogen fuel cell technology. Toyota is using the same proton exchange member fuel cell (PEMFC) technology that it has already commercially deployed in Mirai fuel cell passenger cars. The Kenworth Class 8 tractor used by Toyota in the project incorporates two Mirai PEMFC stacks in parallel (totaling about 230 kW of peak power output), hybridized with a small battery pack (about 12 kWhr). Under the initial “Project Portal” effort, Toyota has been testing its first prototype PEMFC truck in local drayage service, from Toyota’s Port of Long Beach facility. In mid-2018, Toyota launched a second “Beta” model, which reportedly offers longer range (increased from 200 to 300 miles), and other improvements. Notably, Toyota’s apparent ultimate plan is to sell this heavy-duty PEMFC drive system to Class 8 truck OEMs (rather than to become a Class 8 OEM itself).
In a major new program related to Toyota’s Portal Project, CARB has awarded $41 million to the Port of Los Angeles to develop and demonstrate 10 ZE Class 8 fuel cell tractors using Kenworth’s T680 platform. This award is part of California’s Zero-Emission and Near Zero-Emission Freight Facilities (ZANZEFF) program. Under a collaboration between Kenworth and Toyota, these fuel cell drayage trucks will be built specifically to move cargo from POLA terminals to local distribution centers and inland destinations. The 10 fuel cell tractors will be operated by Toyota Logistics Services, United Parcel Services, Total Transportation Services Inc., and Southern Counties Express. In a second phase of the project, two new “large capacity heavy-duty hydrogen stations” will be developed by Shell to serve these fuel cell trucks (one in Wilmington, one in Ontario).
Barriers to Commercializing Hydrogen Fuel Cell Trucks
The current cost of hydrogen fuel is a significant barrier to commercialization of heavy-duty fuel cell vehicles.
For heavy-duty fleets, fuel costs are second only to labor costs in determining total operational costs. The current cost of hydrogen fuel, which is currently much more expensive than diesel, is a significant barrier to commercialization of heavy-duty fuel cell vehicles. Hydrogen costs approximately $10 to $15 per kilogram, which translates to about $12 to $18 per diesel gallon equivalent. On the positive side, the higher cost and relatively small volumes of on-board hydrogen are partially compensated for by the relative higher efficiency of a fuel cell electric-drive system, compared to a conventional-drive diesel truck. Fuel cell makers such as Ballard Power Systems are working hard to further reduce total cost of ownership by improving stack life, reducing capital costs, improving power density, and other advancements. Ballard indicates that its PEMFC stacks for heavy-duty vehicle applications will be commercially available in 2019.
Similar to compressed natural gas (CNG) vehicles, emerging heavy-duty fuel cell vehicles are designed to use compressed hydrogen, which is stored onboard in heavy, expensive high-pressure tanks. While on-board CH2 storage is robust and proven (using similar technology as CNG tanks), it presents significant tradeoffs on cost, range and other factors that are very important to the bottom line in heavy-duty trucking. Further optimization and advancements for hydrogen fuel systems may be required before heavy-duty FCVs can meaningfully penetrate into on-road HDV applications, especially in Class 8 trucking.
While on-board CH2 storage is robust and proven, it presents significant tradeoffs on cost and range.
As noted, today there is almost no hydrogen fueling infrastructure designed to serve medium- and heavy-duty FCVs. The limited existing or planned hydrogen fueling stations designed to serve passenger vehicles are not equipped to fuel heavy-duty FCVs. Except for a few demonstration programs, the only hydrogen stations that can accommodate heavy-duty FCVs are located on transit properties and designed to refill fuel cell buses. It’s likely that the initial approach to build out a hydrogen fueling network for heavy-duty trucks will focus on a “corridor” concept; this will take many years to orchestrate, and each station will cost roughly $3 million. To build-out a national network of heavy-duty FCV fueling stations, it will likely take decades and cost billions of dollars. Careful coordination will be needed with the pace of rolling out the heavy-duty FCVs that will utilize such stations.
Funding Opportunities Available and Abundant
Fortunately, more and more grant funding opportunities are becoming available to help fund deployments of heavy-duty fuel cell vehicles, as well as the hydrogen stations that will serve them. Funding to offset the higher capital costs of heavy-duty FCVs will be critical for fleet managers to purchase the vehicles and take on the risks associated with new fuel-technology platforms. California’s ZANZEFF grants provide a recent example of forward momentum. Each state is just beginning to award its collective $2.925 billion in funds from the VW settlement. Regional agencies like the South Coast Air Quality Management District are dedicating significant portions of their incentive and R&D funds towards heavy-duty FCVs and hydrogen stations.
There is solid movement towards hydrogen fuel cell systems meeting their potential to become commercially available.
Heavy-duty hydrogen FCVS – including in the most challenging applications like Class 8 trucks – are beginning to gain momentum. They are moving from proof-of-concept first-generation platforms into pre-commercial prototypes that are beginning to log significant real-world demonstration experience. Clearly, there are reasons in 2018 to be optimistic about heavy-duty fuel cell vehicles in the U.S. The greatest reason is the expanded interest and involvement seen from mainstream, fully proven truck OEMs as they iteratively move beyond diesel ICE platforms to zero-emission battery-electric and fuel cell platforms. Albeit gradual, there is solid movement towards hydrogen fuel cell systems meeting their potential to become commercially available as zero-emission alternatives to conventional diesel HDVs.