CO2 emissions from road freight transit must be reduced. Electric drives are suitable for short distances, whereas hydrogen is a viable option for longer journeys. However, numerous aspects concerning the H2 drive remain unknown.
Hydrogen may one day provide climate-friendly energy for long-distance trucks. However, it is unclear how or in what form this potential ingredient will be implemented in Europe’s vehicles at the moment. However, time is of the essence.
The debate continues over whether the green vehicle of the future should run entirely on hydrogen or whether it would be wiser to use batteries. Even the industry is divided on this issue: while industry titans Daimler and Volvo Trucks recently formed a hydrogen alliance, Hyundai is already testing its first hydrogen-powered vehicles on European roads, and Toyota has at least announced its development, VW’s profitable Scania subsidiary recently halted further work on the fuel cell. Thus, it sided with Tesla, which also views the battery as the future’s solution.
Hydrogen for long-distance travel
Both approaches, however, may coexist. Berylls, for example, proposes for hydrogen to be used largely on long-distance routes in its current study, “Trucking on Hydrogen at a Crossroads.” Batteries are simply too expensive, too huge, and too heavy to enable lengthy ranges in that location. The batteries would use so much space and payload that there would be virtually no space left for recharge.
“A tank of hydrogen weighing 80 kg contains over 2,700 kWh of energy and enables ranges of over 1,000 kilometers. A similar battery will be unavailable in the medium term due to cost and weight considerations “Steffen Stumpp, Berylls’s commercial vehicle manager, summarizes the benefits of gas.
The fuel cell outperforms the combustion engine
Additionally, Stumpp provides an answer for the second question. It comes down to how hydrogen is used in the vehicle – as fuel for an internal combustion engine or as a source of electricity in a fuel cell. Stumpp believes the latter will prevail due to its efficiency. Additionally, it permits recuperation via the electric drive train, releases no nitrogen oxides, and so eliminates the need for sophisticated exhaust gas aftertreatment.
Other scientists view the fuel cell’s superior efficiency as a decisive factor. After all, hydrogen is and will remain an expensive energy carrier; using such a high-priced fuel in an inefficient engine would be a waste of money. Even with the significantly more efficient fuel cell, the high costs could become an issue: “To attain competitive kilometer costs, hydrogen at the filling station must be less than five euros per kilogram,” Stumpp adds.
By 2030, there will be insufficient green hydrogen
For years, car drivers have paid just under ten euros at the pump – a price that would have to be half for trucks. According to the International Energy Agency (IEA), this might be accomplished once large-scale production of green hydrogen commences on a global basis. However, the gas is currently not created from water using renewable energy, but rather from natural gas via the CO2-intensive process of steam pyrolysis. Using this gray hydrogen in transportation has little benefit for the climate.
Even the “blue” and “turquoise” versions of the gas, which separate and store portions of the carbon, are far from CO2-neutral. Large-scale production will almost certainly take some time to transition. Stumpp estimates that sufficient green hydrogen for long-distance haulage in Germany will not be accessible until 2030. Until then, he can envision a transitional phase with versions of varying colors.
Gaseous version is inapplicable
However, the dilemma of whether hydrogen should enter the truck in a liquid or gaseous condition persists. Four fundamental forms are feasible, two of which have already been ruled out for Berylls. One is the pressurized gaseous variant, which is recognizable from early fuel cell cars as well as buses and trains. Due to the low pressure, the energy density is inadequate, resulting in an insufficient range per tankful for vehicles.
However, even the most energy dense form, cryo-compressed hydrogen cooled to minus 235 degrees, is not an option. According to experts, it is prohibitively expensive, overly hard to manage, and not yet fully evolved. Automobile enthusiasts may be familiar with the technology from the BMW Hydrogen 7’s late versions, with which the Munich-based business temporarily introduced the hydrogen burner in small series at the turn of the millennium.
Hydrogen standards will be established
This leaves two possible configurations: 700-bar compressed hydrogen gas (cGh2), as used in passenger cars, and cooled, liquefied hydrogen (LH2, minus 253 degrees), as utilized in Daimler’s GenH2 truck project. Both modes of mobility necessitate the development of specifically adapted transportation systems, recharging stations, and automobiles.
The entire logistics and infrastructure chain must conform to the delivery format – but this demands standards that have previously been lacking. “Within the next two to three years, we expect truck manufacturers, filling station operators, and hydrogen producers to agree on criteria that meet customer expectations,” Stumpp adds.
If the industry wishes to contribute to climate protection, it does not have much more time. According to the former German government, greenhouse gas emissions from the transport sector must be reduced from their current level of around 146 million metric tons per year to a maximum of 95 to 98 million metric tons per year by 2030 in order to reach near-zero levels by 2050, as the EU envisions. Freight transportation is critical to this: 73% of commodities in Germany are moved by truck on public highways. And the trend is continuing to grow.
