Toyota Develops 3rd Gen Hydrogen System For Long Haul Trucks
Source： eepower
Toyota Motor Corporation has reinforced its strong interest in powering transportation with hydrogen fuel cells by developing a third-generation fuel cell system (3rd Gen FC System) for heavy-duty commercial trucks. The system could replace conventional diesel-powered engines.
Toyota has long viewed hydrogen as important in carbon-neutral transportation and has emphasized fuel cell development over battery electric vehicle (BEV) technologies. Fuel cells use a catalyst to combine hydrogen and oxygen, producing electricity, water vapor, and a small amount of heat. Automakers like Toyota, BMW, GM, Honda, and Mercedes-Benz have been working to develop hydrogen fuel cell-powered vehicles for decades, but with little actual commercial success.
Toyota launched its MIRAI fuel cell electric vehicle (FCEV) in 2014 and has sold approximately 28,000 FCEVs in more than 30 countries. The small number of hydrogen fueling stations available worldwide has largely limited the sales of the Toyota Mirai FCEV. Since 2019, Toyota has also supplied its fuel cell systems for use in applications such as buses, railroads, and stationary power generators.
Heavy Duty Applications
Global freight emissions account for 25% of transport-related greenhouse gases despite representing only 4% of vehicles. In addition to carbon dioxide (CO2) emissions, diesel engines produce fine particulate matter pollution that has been linked to various respiratory illnesses, cardiovascular disease, and cancer. Hydrogen fuel cell trucks produce only water vapor and heat during operation, eliminating direct emissions of CO₂, nitrogen oxides, and particulate matter. Unlike battery-electric vehicles, whose emissions depend on grid electricity sources, if hydrogen trucks could be powered by green hydrogen (produced via renewable-powered electrolysis, for example) they could achieve nearly full lifecycle decarbonization.
Hydrogen’s energy density of 120 megajoules per kilogram—three times higher than diesel—makes it attractive. Hydrogen fuel could enable a heavy truck to achieve ranges exceeding 500 miles per 100 kg tank, roughly comparable to a diesel-powered truck. Refueling from a special hydrogen pump could take just 8-20 minutes, rather than the long charging times required to recharge a battery electric-powered semi-truck.
The 3rd Gen FC System replaces a diesel engine. Image used courtesy of Toyota
Tesla, Freightliner, Volvo, and others are hard at work on heavy-duty, long-haul battery-powered trucks. However, one limiting factor has become apparent: the weight of the battery pack used to store the electrical energy used to power the vehicle. The U.S. allows electric trucks to be 2,000 pounds heavier than diesel trucks, partially offsetting the battery weight, but every pound of battery weight is a pound less available for cargo. Removing the diesel engine, transmission, and fuel system saves some weight, compensating for part of the battery weight.
For example, while the exact battery weight for the Tesla Semi has not been officially confirmed, estimates based on available information suggest it has a battery capacity of 850-900 kWh. The estimated battery weight would be around 10,000-11,000 pounds (4,536-4,990 kg). For the Freightliner eCascadia, the battery capacity is up to 438 kWh. While the battery weight is not explicitly stated, the truck weighs about 4,000 pounds (1,814 kg), more than a diesel equivalent. Volvo’s EV Heavy Truck has a battery capacity of up to 540 kWh (6 battery packs of 90-kWh each) with a battery weight of 1,113 pounds (505 kg) per 90-kWh pack and a total battery weight of 6,680 pounds (3,030 kg) for the 540-kWh pack.
For an equivalent range, hydrogen’s energy density advantage allows fuel cell systems to weigh 500-1,000 pounds less than the 3,000-11,000 pounds of batteries required for a battery-powered truck. Thus, a Class 8 hydrogen truck sacrifices only 1.5% of its 80,000-lb gross weight to powertrain components, whereas BEVs lose 5-18%. Space utilization is also important, and an FC and hydrogen storage can be incorporated into the chassis design without requiring the space that large-scale battery packs would require.
Toyota’s FC System
Toyota’s 3rd-Gen FC System is 1.2 times more efficient than previous designs and twice as durable. The company claims its 3rd Gen system is nearly as durable as diesel engines and is almost maintenance-free.
Hydrogen Limitations
Hydrogen is not without its problems. A fuel cell’s efficiency is around 50-60%. When adding the losses from making green hydrogen through electrolysis and compressing the gas to store it, the overall efficiency drops to 30-40%. That’s about what the best modern diesel engines can attain, but far lower than the 80-90% overall efficiency possible with a battery-powered vehicle. Currently, more than 90% of industrial hydrogen is produced from fossil fuels, a process that creates significant greenhouse gases. Green hydrogen could be made from excess renewable energy. However, producing 1 kg of green hydrogen requires 50-55 kWh of renewable electricity, enough to power a BEV truck for 150 miles versus the 50-60 miles that a hydrogen truck could travel on 1 kg of hydrogen. Hydrogen trucks are expected to cost from $200,000 to $600,000—double the cost of diesel trucks—due to expensive fuel cell stacks, platinum catalysts, and carbon-fiber hydrogen tanks.
Fuel cell stacks degrade 2-3% annually due to membrane contamination and catalyst issues. They must be replaced every 50,000-100,000 miles. By contrast, BEV batteries retain 80% of their capacity after 500,000 miles. Hydrogen trucks also require rigorous maintenance of high-pressure valves, moisture control systems, and cryogenic pumps. Toyota’s Project Portal trucks in California mitigated these issues via modular fuel cell designs, but fleet-wide reliability remains unproven.
Hydrogen’s low ignition energy (0.02 mJ) and wide flammability range (4-75% concentration) necessitate explosion-proof tank designs and leak detection systems. While modern carbon-fiber tanks can withstand more than twice the hydrogen storage pressures (875 bar) and ballistic impacts, regulatory gaps persist in certifying large-scale hydrogen transport.
As of 2025, only 160 public hydrogen stations exist globally, concentrated in California, Europe, and East Asia. This highlights the logistical challenges of deploying cryogenic storage and 700-bar dispensers. Building a single heavy-duty station costs $4-6 million and requires 22-28 MW power connections for on-site electrolysis, compared to 1–2 MW for BEV mega chargers.
Operational Performance
Hydrogen has significant advantages over BEVs in long-haul applications. However, the requirement of battery energy storage means that BEVs face range and payload penalties as their range increases. A 750-mile BEV truck, for example, requires a 1.5 MWh battery weighing 15,000 pounds and results in a payload reduction of 18%. Hydrogen trucks can achieve comparable ranges with 1,000 pounds of tanks, fuel cells, and equipment.
A hydrogen truck could provide a good solution for long-distance hauling over a set route, with dedicated hydrogen fueling stations located at appropriate intervals. This type of long-haul trucking can be found in places like the U.S., Australia, Russia, and China, and an FC system like Toyota’s has potential. For short-haul routes, a BEV with a 300-mile range suffices for up to 80% of freight trips under 200 miles at half the total operating cost of hydrogen. Until problems with prohibitive costs, embryonic infrastructure, and energy inefficiencies can be addressed, hydrogen trucks will remain niche solutions, complementing rather than displacing BEVs in the zero-emission freight ecosystem.