Mercedes-Benz hydrogen truck prototype covers more than 650 miles on one fill

Daimler Truck said it achieved a milestone with its Mercedes-Benz hydrogen fuel cell truck — exacting 650 miles on just one tank of fuel earlier this week.

The Mercedes-Benz GenH2 truck is powered by a hydrogen fuel cell system built by Cellcentric, a joint venture with rival Volvo Group. The truck, which has a gross combined vehicle weight of 40 tons, began its journey in Woerth am Rhein, Germany, on Monday afternoon and finished Tuesday morning in Berlin.

Such long routes will be necessary to meet demand for zero-emission trucks that can travel as far as their diesel counterparts. Daimler is developing fuel cell technology for both the European markets and the U.S., where it owns the Freightliner truck brand.

The GenH2 features a different architecture from most of the fuel cell commercial vehicles under development and the small number of passenger cars on the road. It uses a liquid hydrogen fuel tank, which Daimler leaders said is preferable because of its higher energy density in relation to its volume.

But debate is developing about whether liquid or gaseous hydrogen is the best way to store energy in fuel cell vehicles. Liquid hydrogen's greater energy density provides a longer range. But both the storage and fuel pump technology must function at an extreme minus 253 degrees Celsius. Gaseous hydrogen requires pressurization and more extensive fueling infrastructure, but doesn't have the same temperature constraints.

Daimler said it expects to introduce the series version of the H2 truck in the second half of the decade, though hydrogen infrastructure availability remains an impediment to speedier adoption and, therefore, speedier production. Cellcentric's hydrogen fuel cell can process liquid and gaseous hydrogen, though both are in short supply.

"We can be even faster," Andreas Gorbach, the head of truck technology at Daimler, said at a briefing Tuesday. "The bottleneck for the speed here is infrastructure, energy availability. We aim for the second half of the decade because we don't think the infrastructure will be any faster."

Daimler's dilemma is one facing the entire hydrogen-powered vehicle sector. While hydrogen appears to be a good solution for long-haul truck fleets seeking to avoid lengthy charging times and heavy battery weights, the simple molecule is not widely available at filling stations now.

There are only 57 public filling stations in the U.S., according to the Department of Energy. All are in California, and mostly in urban areas rather than along the interstates and highways used by long-haul trucks.

Additionally, hydrogen's current production methods are carbon-intensive, and cleaner methods are extremely expensive.

Long range is key for long-haul trucking, but a battery with a range of 350 miles on a single charge can weigh more than 10,000 pounds. So far, weight remains a limiting factor for battery range.

Daimler is among several manufacturers working on hydrogen truck technology.

Nikola Corp. is slated to deliver hydrogen fuel cell trucks this year, while Hyundai says it will sell an American version of the Xcient Class 8 fuel cell tractor this year as well. Toyota plans to start assembling fuel cell modules at a plant in Kentucky later this year, and has an agreement to provide them to Paccar, which owns the Peterbilt and Kenworth truck brands.

Daimler has sought to emphasize its long history, rock-solid relationships and top-tier service reputation as the hydrogen competition heats up. Its Freightliner has about 40 percent of the heavy truck market share in the U.S. While Daimler will likely not be the first to market, the company is hoping other advantages will bring it out on top.

"We have the scale, know-how and fuels and experience," said Gorbach. "I don't know any other player with all" those ingredients.

Daimler already has battery-electric truck and bus models in production and is developing a hydrogen combustion engine vehicle in addition to the hydrogen fuel cell truck. Daimler owns the Mercedes-Benz truck brand. The car company is a separate business following a 2021 split.