Hydrogen lorries are seen as a promising alternative for emission-free road freight transport. However, before they can be used in large numbers, a number of technological and economic questions still need to be answered, the DACHSER reported.
As part of the “From the Future Lab” series, results from the Corporate Research & Development department are presented, which were developed in close collaboration with various specialist departments and branches as well as the DACHSER Enterprise Lab at the Fraunhofer IML and other research and technology partners.
Hydrogen (H₂) can be used to power heavy commercial vehicles with virtually zero emissions – i.e. without direct emissions of greenhouse gases (primarily CO₂) and air pollutants (nitrogen oxides, soot, etc.). H₂ trucks are therefore among the zero-emission vehicles legally defined in the EU, which are favoured when it comes to bans on entering city centres or truck tolls, among other things.
In contrast to battery-electric vehicles (international abbreviation “BEV”), H₂ trucks are still at a different technological or implementation stage. While BEV trucks will gradually become available as series vehicles for local and, from 2025, long-distance transport with a range of up to 500 kilometers, H₂ vehicles are only available as prototypes and, at best, as small series vehicles. It is currently still unclear which hydrogen drive and which refueling process will prevail.
A fundamental distinction must be made between H₂ trucks with an internal combustion engine drive (H₂-ICE) and vehicles with a hydrogen fuel cell electric drive (FCEV). H₂-ICE trucks use existing gasoline and diesel technology. Hydrogen is injected into a piston engine and ignited, and the energy released is converted into movement and heat. The advantage and disadvantage of this technology: it is based on today’s mature combustion technology. This is currently an advantage, but with the increasing shift towards electric vehicle platforms, this may also prove to be a disadvantage in the future, as OEMs will focus on one platform in the long term. In addition, the H₂-ICE emits minimal residual emissions of CO₂ and air pollutants. Of the major commercial vehicle manufacturers, MAN, Volvo and Daf have announced that they want to further advance the development of H₂ combustion technology.
The majority of leading commercial vehicle manufacturers rely on fuel cells for hydrogen: As part of a catalytic reaction, hydrogen atoms in the fuel cell are lightened by an electron. This creates electrical current, which is either consumed directly by the electric drive or stored in a buffer battery. In combination with the oxygen sucked in from the air, the reaction produces water vapor (H₂O) and heat as “waste products”. The FCEV truck is based on the electric platforms of e-mobility, and the technology is more efficient than comparable H₂ ICE drives. Daimler Trucks, Volvo and Iveco in particular are working on such truck concepts for tractor units and already have FCEV prototypes on the road. However, real series vehicles with the associated service network have not been announced until the end of the decade. The South Korean manufacturer Hyundai is now producing a small series of FCEV trucks with the Xcient Fuel Cell. DACHSER has also been using a Hyundai H₂ motor vehicle with a trailer in two-shift operation for over a year. The vehicle, based in Magdeburg, with its range of over 400 kilometers, usually commutes between the state capital of Saxony-Anhalt and Berlin without any problems.
The fuel cell technology itself is already quite mature in trucks. What is still missing is a standard for storing hydrogen in the vehicle. Three systems are fighting for dominance here:
The standard for city buses and, for example, also used in Hyundai trucks is the storage of gaseous hydrogen in 350 bar pressurized gas cylinders. The 350 bar technology is tried and tested, and the number of filling stations using this technology is correspondingly high. But the big disadvantage: the pressurized gas cylinders take up a lot of space, so that with the specified vehicle dimensions, ranges of more than 500 kilometers can hardly be achieved without losing loading space for the cargo. This means that 350 bar does not result in a direct range advantage over BEVs.
Manufacturers such as Daimler and Iveco are therefore relying on 700 bar technology. The hydrogen, which is also stored in cylinders under higher pressure, leads to ranges of around 750 kilometers without losing loading space. A corresponding 700 bar filling station network for trucks is to be created on the core motorway network in the EU by 2030 based on the AFIR directive.
Daimler is pursuing the most ambitious H₂ storage technology. Hydrogen (LH₂) liquefied under pressure and cold is to be filled in special containers as a liquid. Comparable to LNG technology, where natural gas is liquefied under cold and pressure. The high energy density of LH₂ technology should allow truck ranges of over 1,000 kilometers. Due to the high energy expenditure for liquefaction, this H₂ storage technology is currently the furthest away from being widely available.
In a direct comparison of costs, H₂ technology is currently also lagging behind BEV trucks. Due to the lack of series production, FCEV trucks cost more than twice as much to purchase (Capex) as comparable BEV trucks. In terms of operating costs (Opex), the energy consumption of the F vehicles and the price of green hydrogen or electricity including the costs for the refueling or charging infrastructure are relevant. However, price levels in Europe vary greatly here.
H₂ trucks could have an economic advantage over BEVs if either ranges of well over 500 kilometers or operating times play a role in the calculation. If, for example, valuable driver time is tied up in BEV charging due to a lack of fast chargers available or if 20-hour daily operation of the BEV vehicles cannot be mapped out, then the H₂ truck could be an advantage in the overall cost analysis due to its short refueling times of around 15 minutes.
H₂ truck providers urgently need to create clarity on refueling standards so that investments can be made in infrastructure expansion and series production can start. This is the only way the H₂ truck can make its contribution to climate protection. From DACHSER’s point of view, logistics needs all zero-emission technologies approved for road freight transport in the EU. In the often heated debate “BEV versus H₂”, the following statement applies: It is not a question of “either-or”, but rather we need a clear “both-and” in the electric-hydrogen debate.
Photo of DACHSER
Press release https://shorturl.at/9tXXm
