When we are discussing alternative means of propulsion, we cannot disregard fuel cells.
The reason is not that this technology will have its breakthrough in the near future and will soon be available for customers, but rather that it has been among the favorite projects in the automotive industry for years, mainly because it offers a model that car manufacturers understand. Instead of an engine burning gasoline or diesel in a controlled reaction, transforming the fuel into motion energy, there is a fuel cell that burns hydrogen in a controlled reaction and transforms it into motion energy. Liquid hydrogen is saved in tanks and filled into the car just like a liquid fossil fuel.
The drop of bitterness with this method is that even a fuel cell does not need as many components as a combustion engine and you therefore need fewer workers. But fortunately this vision of the future is still very far away, and nobody in the automotive industry has to worry today about what should happen with all those workers that nobody will need anymore.
Nevertheless, the principle behind the fuel cell is quite promising. When you burn hydrogen, you get water. Accordingly, the exhaust from the car is nothing but pure water vapor. Sadly, reality thwarts us with a series of practical problems. Firstly, pure hydrogen is highly explosive, showing a “strong exothermal reaction”, as a chemist would put it. The tragic fate of the Hindenburg blimp shows clearly just how explosive it is. At the time, dirigibles were filled with hydrogen. Since it is lighter than air, this let the dirigibles rise Germany did not have enough or any reserves of helium, which is a noble, or inert gas and does not burn in contact with oxygen or react with other substances. Hence, they had no choice but to use hydrogen. We all know what happened.
So we understand that hydrogen must be stored with appropriate safety precautions.
It is first synthesized, i.e. generated by using energy, because it does not exist in a pure form anywhere on our globe. Refining of fossil energy carriers is the most frequently found way of manufacturing. Hydrogen is separated when hydrocarbons are split.
And that does not make this process any more environmentally friendly. Another type of hydrogen synthesis is electrolysis, which allows you to obtain hydrogen directly from water. But this method is energy intensive and therefore expensive.
The degree of efficiency is no more than about 60% to 70%. Almost half the energy is lost during electrolysis, and since hydrogen must be kept cool, you need further energy for storage and transportation. Since the degree of efficiency of the fuel cell itself is only 60% as well, and it takes some time before the hydrogen is finally translated into motion energy, the entire chain of processes takes up three times as much energy as the hydrogen filled into the car will be able to provide.
In contrast to this, the degree of efficiency of electric vehicles is more than 80%, combustion engines may achieve 40% in an ideal scenario only due to loss because of heat and friction.
Another shortcoming of fuel cells is the supply infrastructure. As for today’s fossil fuels, an entire network of fuel stations and pipelines has to be provided for hydrogen, a network that has yet to be implemented, starting from zero. This is the aspect that Professor Hans-Peter Lenz from the TU Vienna also perceives as one of the greatest obstacles. The cost for a hydrogen fuel station was estimated at about €2 million in 2010.
If it existed, and hydrogen was not so expensive, vehicles could be refueled just as quickly as they can be refilled with the liquid fuels we are using today. Traditional fuels have a price per kilometer of one third of the price for hydrogen. While the fuel cell infrastructure is completely missing, we do, however, have power for electric vehicles in every household today. The network exists and is extended step by step. The introduction of quick charging stations is less expensive because there are not as many environmental regulations to consider than for fossil or hydrogen-based energy carriers. In addition, electric mobility is gaining on charging speed.
All this leaves us in the paradox situation that the same automobile managers who are telling us that electric vehicles are not suitable for daily use because there are no charging stations, seem to go “blind” on both eyes when they talk about fuel cells and do not want to acknowledge the same problem here. A survey done by the consulting company KPMG showed just how widespread those ideas are among managers of car manufacturing companies. 78% of the participants in the survey considered fuel cells to be the real breakthrough for electric mobility while 62% believe that electric vehicles with battery cells must necessarily fail due to problems of infrastructure. The geographic differences could not possibly be any greater. 70% of the European managers in the automotive industry expect battery vehicles to fail, an opinion shared by only 34% of Chinese managers.
More challenges lie on the way, however. Fuel cells emit energy steadily, but a vehicle requires more energy when accelerating. Additional batteries have to be installed in the vehicle in order to deal with energy peaks. This makes the car heavier, more complex and more expensive. There are several reasons why automobile managers still hang on to fuel cells. They may actually believe in them. Another reason may be that they are a technically interesting and challenging technology with great promises. Or else it may be that they have already put so much money and effort and their own reputation is at stake now, since ceasing work on this project would be interpreted as failure.
However tempting and promising the fuel cell model may be, there are too many open questions: for example, it seems unlikely that our Max or our Sophie will already be riding around in vehicles with such a propulsion by 2030. Small wonder that Mercedes now wants to abandon the project – just a few weeks after the company made a grand statement confirming the work that went into the development process. Meanwhile, electric vehicles have surpassed fuel cells both technically and economically.
The fuel cell is currently the equivalent of riding a dead horse.
This article was also published in German.