ATLANTA — Move over, Tesla Semi. Hyundai has the newest and coolest big rig in a fuel-cell-powered tractor and a nitrogen-cooled trailer introduced here today at a big truck show. The truck part (tractor) is the Hyundai HDC-6 Neptune concept with as many as eight hydrogen tanks propelling itself farther than even what Tesla promises for its semi.
A plucky band of automakers, led by Hyundai, continues to believe the future of transportation, especially long-haul trucks, is better served by converting hydrogen to electricity to feed electric motors. The added weight of batteries in a long-haul truck cuts too heavily into the common 80,000-pound limit for tractor, trailer, and cargo. For local-delivery trucks and for passenger cars, battery electric vehicles still make sense.
What Hyundai showed at the North American Commercial Vehicle (NACV) show is a concept. Turning the truck and trailer into commercially available vehicles requires a bigger fuel cell and regulatory approval. A fleet of 1,600 smaller fuel cell-electric trucks is being delivered now through 2023 in Switzerland, which places a heavy highway tax on diesel trucks.
The HDC-6 Neptune tractor is a Class 8 truck, meaning it’s the front end of a tractor-trailer combination weighing 80,000 pounds, including cargo. Until self-driving gets real (the 2030s, most likely), Hyundai envisions the cab as a “personal studio” space for driver and co-driver. Because there’s no engine or transmission, the floor is low, the ceiling is tall enough for NBA players, and the sleeping area is up top, up three stairs. The rear of the truck cab has a refrigerator, cooktop, microwave, what looked to be a small washer-dryer, and — drumroll — a toilet and shower. That’s exactly what America needs — America’s truck drivers need — with interstate truck rest areas full and parked trucks spilling out hundreds of yards beyond the rest areas. In the future, with full self-driving (Level 5) the tractor could be downsized with the entire cab filled with hydrogen tanks.
According to Dr. Maik Ziegler, vice-president of Hyundai’s commercial vehicle R&D strategy group, battery power means more steps and more complexity. The goal, Ziegler said, “is to provide electrons to the motor.” That will be accomplished more efficiently, he believes, with fuel cells, where the fuel cell stack combines onboard hydrogen with oxygen in the air to produce water — definitely not a pollutant — while throwing off electrons every time two parts hydrogen meet with one part oxygen.
A long-haul battery-electric tractor capable of a full day’s drive weighs a freaking ton extra — 10-12 tons extra, actually — because of the lithium-ion batteries when it’s something like the Tesla semi. That’s compared with a diesel-engine truck with fuel, which needs 85-100 pounds of fuel to drive 100 miles. A fuel cell electric truck might have 2,000 to 4,000 pounds of added weight, mostly in the carbon fiber, bulletproof tanks. Enough hydrogen to go cross-country weighs less than 100 pounds. Hydrogen is stored at 350 bar (5000 psi) or 700 bar (10,o00 psi), or as liquid hydrogen. Hyundai’s fleet of passenger cars, centered on Southern California, uses 700 bar tanks. The higher the pressure, the heavier the tanks must be.
“If you need to charge a truck quickly, you need a one-megawatt power source,” Ziegler says. “If you want to charge 1,000 trucks, you need a nuclear power plant.” (Or a big-city-size power gas or coal power plant, but nukes sound more ominous.)
The cost of hydrogen needs to fall further, Ziegler says. If it’s created using wind or solar as a power source, it’s a clean fuel. He said Australia, with abundant sunshine and land, has the potential to be a major supplier.
The trailer concept is from a Hyundai subsidiary, Hyundai Translead. The 53-foot refrigerated trailer (reefer) is cooled by a big nitrogen tank under the load floor. Much as traditional refrigeration is done, by allowing a gas to expand inside closed metal tubing and become cold, this truck uses nitrogen. Once the nitrogen has expanded, it’s vented to the outside air. Since the earth’s atmosphere is 78 percent nitrogen already, there’s no air pollution.
The sides and top are made of rigid foam inside plastic inner and outer layers. There are no metal rivets, a major source of heat intrusion into a traditional reefer. Stuart James, chief sales officer of Hyundai Translead, says the onboard load of nitrogen should keep the cargo cold for at least three to four days. Monitors and telematics track temperatures in five 10-foot zones, warn if the cooling system has issues, and if nitrogen inadvertently gets into the cargo box — 100 percent nitrogen will not support life — it shuts down the cooling system.
As for when such a vehicle might become a commercial entity, Hyundai says it needs to judge commercial and government demand. In polluted megacities, some are headed toward banning diesel trucks, so the options drop to electric vehicles powered by batteries or fuel cells.
Meanwhile, Tesla and Nikola Motor are moving toward Class 6 to Class 8 trucks that are battery-powered. Nikola is working on hydrogen power as well. Production of the Tesla Semi has been delayed until at least 2020 and possibly 2021.