Hydrogen fuel cells key to powering trucks of the future
The electric vehicles of the future will consist of both plug-in electric vehicles and hydrogen-powered vehicles, with the transition towards both already well underway.
While the number of plug-in electric vehicles is already rising sharply, many truck manufacturers around the world are also starting to put hydrogen-powered trucks on the road, or have already done so.
In fact, it is anticipated that within the production of solutions for powering electric vehicles, fuel cells have the potential to capture 10-20% of the market due to the advantages they can offer heavier vehicles.
Such was shared in a Trumpf online press conference this afternoon discussing how German suppliers can promote fuel cell production.
Hydrogen for heavier vehicles
In order to meet the increasingly stringent climate requirements outlined by governments, the automotive industry has long since been adapting its strategy towards electromobility.
While the majority of this focus has been towards the development of improved battery technologies and the large-scale rollout of plug-in electric vehicles, in the case of heavier vehicles such as trucks and buses, long ranges will not be achievable with batteries alone – unless major restrictions in payload are implemented.
Consequently, the automotive industry is looking towards hydrogen as a fuel source to complement e-mobility where battery-powered electric drives offer limited advantages. Hydrogen not only offers long ranges and burns cleanly – the only byproduct being water and heat – but vehicles can be refuelled with it almost as fast as petrol/diesel engines, meaning no long waits for batteries to recharge. Hydrogen will therefore be a particularly effective fuel alternative for heavy-duty vehicles.
Development of hydrogen fuel cell trucks is already being driven by established vehicle manufacturers including Toyota, Daimler, Hyundai and Volvo, as well as by start-ups such as Nikola Motor. Suppliers and OEMs have already begun small-series production of fuel cells. New manufacturing facilities with a larger production capacity are currently under construction or at the planning stage across the globe.
Laser welding for hydrogen fuel cell production
The key to unlocking a hydrogen-powered future is mastering the development and production of hydrogen fuel cells. The heart of these cells – known as the stack – consist of many ultrathin stainless-steel bipolar plates, which are responsible for converting hydrogen and oxygen into electricity, water and heat. The electricity is then used to drive an electric motor, propelling the vehicle forward.
However, there exists a great challenge in producing the stack, which unless overcome will keep the manufacturing cost of fuel cells – and consequently the cost of hydrogen-powered vehicles – very high.
Each plate is approximately the size of an A4 sheet of paper and is not much thicker than a human hair. A fuel stack features 300-500 plates welded together, requiring hundreds of thin seams to be made, each anywhere from 3-5m in length and being barely visible to the naked eye. At a weld speed of 1m/s this would result in a single stack taking up to around 40 minutes to weld, with a medium size car requiring one fuel cell stack and heavier vehicles requiring more.
A fuel stack features 300-500 ultrathin stainless-steel plates welded together, each requiring weld seams totalling 3-5m in length (Image: Trumpf)
Most importantly, however, each weld seam needs to be absolutely gas-tight and perfect.
“Even the smallest error would be fatal,” Dr Christian Schmitz, CEO of Trumpf’s Laser Technology, remarked in this afternoon’s press conference. “This is because hydrogen is the smallest molecule in the world, much smaller than natural gas, and it slips through every crack and pore. A single leaky bipolar plate can render a complete fuel cell stack unusable. The welding process must be of the highest quality, and this is best achieved with a laser.”
The welds must be made over complex geometries over a very large area with tremendous accuracy. In addition, stack manufacturers must keep the heat entering the workpiece to a minimum in order to prevent the metal sheets from warping. This stringent list of requirements rules out almost all the available joining processes – apart from the laser.
In recent years the laser industry has therefore mobilised to research and develop new techniques and solutions for perfecting and conducting the complex task of bipolar plate welding. Much of this progress has been covered by Laser Systems Europe, with our ‘fuel cell’ page featuring the latest updates. New solutions cover everything from new, innovative lasers to improved beam delivery and process monitoring systems.
Trumpf is playing an important role in this development, Schmitz explained, with the firm driving the development of additional laser techniques and integrated sensor solutions to make fuel cell manufacturing even more efficient and cost-effective in the future.
While fuel cell could provide an alternative form of electromobility to plug-in electric cars, it is anticipated that they will mostly be used for heavier vehicles such as trucks. (Image: iStock)
“Trumpf cooperates with all the leading companies involved in the fuel cell field,” he said. “In our laser application centres, we work together with our customers to advance the production of bipolar plates – just as we have already successfully done for the production of batteries for electric cars.”
The firm is already considered a market leader in the field of battery production, which has already proven to be an important sales driver for the company. “There are more than 30 applications for the laser in e-car battery manufacturing,” said Schmitz. “Battery-based electromobility will continue to be an important industry for us.”
He added that for Trumpf, e-mobility currently makes up around 40% of the revenue of its laser division.
When asked whether there was a potential market for Trumpf in fuel cell production, Schmitz remarked: “Absolutely, while I think in the coming years the battery will be the driver of very high volume, I think the fuel cell will have 10-20% market share, because for trucks, to do this business with batteries will be difficult – you need range and you need a sustainable, stable power source, and here the fuel cell as the advantage.”
When asked whether hydrogen fuel cells would also be used in standard cars in addition to heavy electric vehicles – thus competing with plug-in EVs – he remarked that he doesn’t think fuel cells will be the solution for cars. This is because batteries are already well-adapted to the weight and distances required of these vehicles.
Fuel cells for automotive and beyond
Hydrogen fuel cells are not only intended for use in trucks, buses or cars. They are also suitable for supplying power to ships, trains, industrial plants and residential buildings, in steel production, the chemical industry and in aviation.
The technology will therefore make a significant contribution to approaching net-zero targets, especially in the commercial vehicle sector.
China has acknowledged this by officially including funding for fuel cells in its national development plan. According to a forecast by the China Society of Automotive Engineers, in China alone, by 2030 there could be more than one million hydrogen-powered vehicles on the road1.
In addition to China, other countries including the UK, Germany, France, Norway, the Netherlands, Japan, South Korea and Australia have also adopted a national hydrogen strategy. Germany’s strategy, for example, will provide a total of nine billion euros to scale up the hydrogen economy into a commercially viable sector2.
Support for hydrogen technology has also been approved by the European Union, which will provide funding of up to 5.4 billion euros3.
International collaboration in particular will be an important element in the production and supply of hydrogen, with internationally connected supply chains being essential to achieving a breakthrough in the hydrogen economy. Initiatives such as that by the leading associations of German and French industry (BDI, France Industrie and Medef) wish to accelerate the establishment of a hydrogen value chain by fostering such close collaboration.
 Automobilwoche trade journal: Der lange Weg zum Wasserstoffauto (The long road to the hydrogen car)
 German federal government: Schub für Energiewende (Impetus for the energy shift)
 Tagesschau news service: EU billigt Finanzierung: 5,4 Milliarden Euro für Wasserstoff-Förderung (EU approves funding: 5.4 billion euros for hydrogen projects)