Hydrogen: On a High Pressure Track to Zero Emission Commercial Vehicles
Author: Hannes Rügheimer
When it comes to the future of operating heavy trucks and buses without emissions, there will probably be no way around fuel cells and hydrogen. Even though commercial vehicle manufacturers are working simultaneously on different drive technologies, H2 is very popular among them.
In early July 2022, Dutch commercial vehicle manufacturer DAF announced that a battery electric 26 ton truck had gone up the Austrian Grossglockner High Alpine Road and back – without recharging once. To simulate realistic conditions, the e-truck had no less than eight tons of water on board. With a fully charged battery, the vehicle covered 68 kilometers in each direction with up to 12 percent gradients and a total of 3,350 meters of altitude. At the end of the journey, the high voltage battery still had a charge level of 45 percent – although this was in no small part due to recuperation on the descent.
The manufacturer cites the experiment as proof of the suitability of battery electric trucks for heavy duty transport. But on closer inspection, it also highlights the limitations of this drive technology. Representing many experts, Dr. Christoph Flink, Vice President of Hydrogen Economy Program Management at DEKRA, states: “Battery electric drives are too big, too heavy, and too expensive, especially for long haul.” Thus, he said, battery powered trucks are primarily of interest for short and medium haul routes. For emission free commercial vehicle e-mobility over longer distances, however, the DEKRA expert currently sees the most promising solution in refueling with hydrogen and generating drive energy using fuel cells. In addition to its use for long distance transport, it also shows advantages in other scenarios that require long ranges or running times between refueling – for example, for coaches, local buses, or commercial vehicles for municipal services such as refuse collection or street cleaning.
Daimler and Volvo rely on freezer tanks
Most commercial vehicle manufacturers see things similarly. Even though many of them are developing and testing battery electric model variants simultaneously, they are focusing primarily on hydrogen for long distance use. Daimler Truck, for example, is working on a fuel cell truck with its “GenH2 Truck”. The prototype, which was showcased at the end of 2020, is based on the Actros series model and has two 40 kilogram tanks for liquid hydrogen cooled to -253 degrees Celsius (so-called sLH2 – “subcooled liquid hydrogen”). The advantage of deep freezing: At this temperature, hydrogen is liquid and more energy dense compared to its gaseous state. This means that hydrogen can be refueled in a few short minutes, just like conventional fuels. In addition, the tanks, which are also cooled to this temperature, require less installation space than gas tanks. The fuel cell system of the GenH2 truck delivers 230 kW (313 hp) of continuous power from the sLH2. An additional battery continuously recharges while the truck is on the move and can “boost” this power up to 330 kW (449 hp) when needed. With this combination, the truck is expected to achieve a range of up to 1,000 kilometers. The concept is scheduled for customer trials to start in 2023, with series production possible in 2026.
Volvo is also aiming for similar ranges. Its as-yet-unnamed hydrogen truck prototype is based on the Volvo FH Electric e-model and could enable a gross vehicle weight of up to 65 tons. Two fuel cells are also fed with the deep cooled liquid hydrogen sLH2, from which they deliver up to 300 kW (408 hp) of power. Roger Alm, president of Volvo Trucks, remains relatively cautious in his assessment of future deployment scenarios: “Electric trucks with hydrogen powered fuel cells are particularly suitable for long distances and heavy, energy intensive tasks. They could also be an option for countries where battery charging options are limited.” He states that a start of production is conceivable for “the second half of the decade”. Until then, Volvo also plans to conduct practical trials with pilot customers.
Cooperation with US companies for 350 bar trucks
Iveco, in turn, is working with US specialist Nikola to develop a fuel cell truck based on the Iveco S-Way truck. A battery electric model will be presented before the end of 2022, and a fuel cell variant could follow in 2023. The South Korean group Hyundai is cooperating with Hyzon, also a US based manufacturer, and already delivered ten “Xcient Fuel Cell” heavy duty H2 trucks from South Korea to Switzerland in 2020. Its 190 kW (258 hp) propulsion system uses two 95 kW fuel cell units. A total of seven tanks store up to 32 kilograms of hydrogen – in this case, however, not deep frozen, but at a pressure of 350 bar. With this solution, the range of a 34 ton trailer tractor is around 400 kilometers. Refueling at a 350 bar filling station is supposedly possible in eight to 20 minutes. Hyundai plans to produce and deliver 1,600 units of its hydrogen truck worldwide by 2025. The South Korean-US constellation of companies is also working intensively on increasing the range to up to 1,000 km on a single tank.
Hydrogen development hotspot close to the birthplace of the automobile
In order to be able to produce fuel cells in the required quantities, Daimler Truck and Volvo founded the joint venture Cellcentric at the end of 2020. In addition to its presence in the Stuttgart region, Cellcentric is also setting up a development and production center in Burnaby, Canada. At its site in Weilheim, Baden-Württemberg, Germany, up to 800 employees will produce fuel cells for both commercial vehicle manufacturers. It is not without pride that the company points to its proximity to the birthplace of the automobile.
Since the beginning of 2020, freight forwarder Große-Vehne, also based near Stuttgart in Germany, has been testing a 26-ton truck with a fuel cell and 350 bar hydrogen storage system as part of the publicly funded “Hylix-B” project. In everyday operation, the vehicle, which is based on the Mercedes-Benz Actros, achieved a range of about 500 kilometers. This corresponds to a hydrogen consumption of around 10 kilograms per 100 kilometers. The company selects its deployment routes based on where H2 refueling stations are actually available. The project’s “Total Cost of Ownership” analysis, which takes into account acquisition, energy, and operating costs, expects hydrogen to have an advantage by 2030 at the latest – especially in view of rising diesel prices.
Retrofits are already being offered as well
In June 2022, commercial vehicle retrofitter Clean Logistics also presented its first zero emission truck with fuel cell technology, the “Fyuriant” H2 truck. The Hamburg based company replaces conventional diesel propulsion in existing vehicles with zero emission drive technology and innovative control technology. In the Fyuriant, one or more high pressure tanks store 40 kilograms of hydrogen at 350 bar each. One fuel cell is used per tank, which can deliver between 120 and 240 kW (corresponding to 163 and 326 hp) to the electric axle with wheel hub drive, depending on application and load profile. Clean Logistics estimates the achievable range at 400 to 500 kilometers. The company is already experiencing high demand for converted trucks and buses – and is therefore massively expanding its capacities.
Infrastructure remains the biggest challenge
Clean Logistics plans to convert up to 450 vehicles per year starting in 2024. Nevertheless, according to the company’s CEO Dirk Graszt, sales prospects depend above all on the availability of suitable hydrogen filling stations. Karin Radström, member of the Board of Management of Daimler Truck AG, also sees the main challenge in the rapid development of a trans-European hydrogen infrastructure. Here, too, the company is relying on partnerships: Together with energy groups BP, Shell, and Total, as well as gas expert Linde, they plan to quickly realize further hydrogen filling stations. Together with Volvo, however, the company is also formulating demands: According to the commercial vehicle specialists, around 300 high performance hydrogen filling stations for heavy commercial vehicles must be built in Europe by 2025 – and around 1,000 by 2030 at the latest. How quickly the triumphant advance of hydrogen technology is achieved in the commercial vehicle sector will likely depend in great part on whether these ambitious targets can be me
Three Questions for Dr. Christoph Flink
Dr. Flink, there is currently a lot of discussion about e-fuels and also battery electric drives as options for commercial vehicles that many manufacturers are relying on. Which drive technology do you think will prevail in heavy duty transport?
Flink: In the long term, the technology that works most efficiently will prevail. Development is indeed in flux and the detailed end result is still difficult to predict. But I’m convinced that hydrogen will play an important part in this technology mix. Purely battery electric drives are too big, too heavy, and too expensive, especially for long distances. And e-fuels – irrespective of the question of cost and energy efficiency – will not be available in the required quantities in time.
For DEKRA, you are primarily concerned with developments in regard to hydrogen. What trends do you see happening here?
Flink: Infrastructure is the most critical issue. We need a rapid expansion of hydrogen refueling stations. This requires trans-European hydrogen logistics, ranging from the production of hydrogen – of course “green”, where possible – to storage, transport, and refueling stations. Technically, we also see a trend toward 350 bar. This trend supports the fact that hydrogen is hardly used in passenger cars and smaller commercial vehicles, where 700 bar refueling was chosen for space reasons. In larger commercial vehicles, on the other hand, the somewhat easier-to-handle 350 bar technology is gaining ground.
What is DEKRA’s role in this context?
Flink: DEKRA is actively involved in hydrogen’s entire logistics and value chain. We advise our customers on the use of hydrogen and certify the safety of industrial plants as well as all the elements of the hydrogen infrastructure just mentioned. Today, DEKRA is one of the market leaders in the safety testing of mineral oil filling stations in Germany. We also strive to achieve this position for HRS, Hydrogen Refueling Stations, in the future. And when it comes to testing the vehicles themselves, we are of course already preparing for a hydrogen future.