A dream come true?

Fuel cells continue to attract the interest of automobile manufacturers

The challenges may consist in stuffing sufficient battery capacity into small and large vehicles or in the recharging infrastructure for electric vehicles, which is still too patchy. Following initial advances by Asian manufacturers, European OEMs are also increasingly researching and developing hydrogen-powered fuel cells.

They could dispense with time-consuming recharging breaks on long-distance journeys and, if the required hydrogen is produced regeneratively, also deliver ecological benefits. The energy generated by the chemical reaction between hydrogen and oxygen in the fuel cell is naturally just as suitable as battery energy for powering traction motors. Fuel cells facilitate the pleasure derived from electromobility even over longer distances interrupted then solely by a few minutes of “refueling.” The only leftover from this reaction is some water vapor discharged from the exhaust, in this case a simple plastic pipe. 

Systems complementing each other

Basically, a fuel-cell vehicle is of course also powered by electricity. The only difference is that the required energy is generated directly in the fuel cell. Although current versions of fuel-cell vehicles do require an additional battery, this can be smaller than those conventionally installed in all-electric cars. After starting, it is only needed for accelerating and for energy recovery when the brakes are applied. BEVs come with the disadvantage of having a heavy and expensive battery requiring comparatively long charging times. They are therefore more suitable as smaller vehicles covering shorter distances. From today’s perspective, batteries are not a viable option, especially for heavy long-haulage trucks. This is precisely where the fuel cell comes into its own: low weight and small footprint coupled with short refueling times. It is thus ideal for larger cars, buses and commercial vehicles, making it the perfect complement to all-electric vehicles. 

Vast interest

A whole string of arguments that make it clear why German manufacturers, first and foremost Mercedes-Benz with its fuel cell variant of the GLC, are now entering this market more enthusiastically, in the wake of carmakers from the Far East. But there can be no electric and environmentally friendly motoring pleasure without the necessary fuel. The hydrogen filling station network is also becoming increasingly tight, as the “H2.LIVE” app impressively illustrates. And refueling a vehicle with hydrogen is completed almost -exactly as quickly as with conventional fuel. “We are seeing increasing interest on the part of manufacturers,” says Dr. Michael Becker, Head of Advanced Engineering at Pierburg.

Since the 1990s, Pierburg has been involved in the development of components for fuel cells

“This applies, on the one hand, to larger passenger cars, and increasingly also to trucks and buses”. His company is now receiving inquiries from all over the world, including for stationary systems that use fuel cells in the form of co-generation systems, for example for heating and energy in buildings. There are sound reasons for these inquiries. Pierburg has been involved in the development of components for fuel cells since the 1990s. Today, the company offers a comprehensive portfolio, both for the hydrogen (anode) and the oxygen (cathode) elements of small energy producers, and beyond that, for the thermal management of this promising technology.

Cathode valve from Pierburg

The electric cathode valve will be used to control the fresh and exhaust air mass flows as well as for the extremely tight shut-off of the fuel cell stacks. The materials specially selected and combined for this application guarantee the necessary resistance to hydrogen as well as high-purity water. The valve contains an electric-motor drive with plenty of reserve power and offers the necessary operational reliability so that no functional impairments can occur even under frost conditions.

Here, too, it has become clear in the course of development work that the experience in combustion technology and the system-engineering understanding of this longstanding development partner of the global automobile manufacturers are valuable factors in coping with new technological challenges. Such experience derives in particular from expertise in air management and pumps as well as actuators and valves. Some of these are very sensitive skills that are essential during the development of a fuel-cell driveline. 

Within the fuel cell, the presence of de-ionized water and hydrogen places special demands on the materials used, particularly with regard to resistance and the hydrogen tightness of the components. At Pierburg, a hydrogen recirculation blower is currently one of the focal points of development. Its task is to return to the stack hydrogen not consumed during the reaction process. Pierburg offers its recirculation blowers as low-voltage and high-voltage variants. They increase the efficiency of the fuel cell and extend its service life.
In addition, the homogeneous distribution of the hydrogen in the cell improves cold-start response.

The 12-volt version of the electric coolant pump is already represented in a fuel cell vehicle

But that’s not all. This automotive supplier can also contribute its expertise in the areas of coolant valves and pumps. With electric pumps for the respective cooling circuits, the company also has high-voltage and low-voltage applications in its range. Incidentally, a 12-volt version is already represented in the -fuel-cell vehicle of a German manufacturer. The company was also recently commissioned by another vehicle producer with a cathode flap for a first low-volume series. This innovative generation of electric flap systems, developed at the Pierburg plant in Berlin, will be used to control the fresh and exhaust air mass flows as well as the ultra-tight shut-off of the fuel cell stacks as from 2022. 

Dr. Michael Becker, Head of Advanced Engineering at Pierburg

Inquired!

Why is interest in the fuel cell currently growing?

There are many and varied reasons for this. The current development focus is shifting toward larger passenger cars and also includes trucks and buses. This is certainly due in no small part to the new legislation for trucks in Europe. Accordingly, CO2 emissions must be lowered by 30 percent in 2030. This cannot be achieved without new technologies, and fuel cells are in themselves predestined for commercial vehicles. In addition, there is local public transport. Trains and buses with fuel cells are already in use on various routes.

How will fuel-cell sales develop in the near future?

Market experts are predicting that we will see large annual gains from the middle of the next decade following the currently low baseline. For 2030, conservative estimates assume that approximately two million fuel-cell vehicles will be produced worldwide. Lead markets will be Asia and Europe. We will see a big boost from the Olympic Games in Tokyo in summer 2020 and in Beijing in winter 2022. The transport infrastructure of these major events will be largely based on hydrogen. 

What advantages does the fuel-cell offer over BEVs?

Apart from the short refueling time, the fuel cell has further advantages. It enables long ranges, is significantly lighter and occupies less space. And, in winter, it works without limitations even at sub-zero temperatures. In a fuel-cell car, you can finally switch on your air conditioning and heating again without having to panic about the range. The fuel-cell vehicle is safely ahead of BEVs in these respects.

Where do you see still unresolved central issues in improving the marketability of fuel cells?

From my point of view, three things are necessary. Firstly, the production of hydrogen must be regenerative throughout in order to achieve the desired ecological effect. Hydrogen can and should also serve as an energy accumulator if, for example, electricity generated by wind turbines is used, especially in times when general consumption is so low that they would otherwise be switched off. Furthermore, work must be done on the infrastructure of the hydrogen filling stations, which is in fact happening as part of various publicly funded initiatives. Finally, of course, there is also a need for a reduction in costs in order to make fuel-cell vehicles more affordable for consumers. With the corresponding economies of scale, there will certainly be a lot happening here in the future.