“Transformation of the Transport Sector Will Primarily Depend on the Energy Transition”

Mr. Kratzsch, up to now the transport sector has lagged well behind the climate protection targets. Are electric cars the solution?

Matthias Kratzsch: Up to now, fleet emission targets nearly all over the world have been based on a tank-to-wheel approach. Unfortunately, this doesn’t go far enough. To make progress towards climate neutrality, we have to make a changeover in primary energy from fossil to renewable sources. In other words, the emission targets in the transport sector can only be achieved by implementing the energy transition. This must take priority over questions about which energy carrier and which type of powertrain are used.

So the issue here isn’t how much CO2 vehicles are emitting?

Kratzsch: Indeed, the key objective is not to reduce the tank-to-wheel CO2 emissions but to prevent further increases in the CO2 content in the atmosphere to the greatest possible extent. What counts is not the emission value in 2050 but the total quantity emitted into the atmosphere by then. In other words, it’s the integral that counts. If we take the CO2 content as a benchmark, in terms of climate protection it can be interesting to extract CO2 from the air to carbonize hydrogen.

In which direction will the energy transition have to go to take the transport sector along with it?

Kratzsch: It’s a case of covering the transport sector’s energy demand with capacities of regenerative generation. This needs an honest approach.

What does “honest” mean here?

Kratzsch: Honest means rating the capacities for generation and storage in such a way that we survive dark doldrum when very little solar and wind energy is available. We cannot convert our own balance sheet totally to green electricity and then be forced to make interim purchases of electricity from foreign nuclear or coal power plants. An honest approach needs storage capacities that are not sufficiently available in Germany, neither with batteries nor with pumped storage plants. We have to come up with other storage solutions that work in the long term and that will let us keep hold of surplus power from the summer until the winter. By the way, storage capacities of this kind are also necessary to stabilize the power grid. As far as customer acceptance is concerned, what counts is which energy carriers are available at which prices and what kind of taxation the state will impose on these energy forms in future.

How do you think this can be done?

Kratzsch: The most obvious solution consists in using surplus electricity to produce hydrogen by electrolysis. There are two ways of storing hydrogen: either in large industrial storage facilities where it can be converted back into power during dark doldrum periods via gas power stations or fuel cells. Or the hydrogen is carbonized to methane, using CO2 from the atmosphere or large-scale industrial CO2 emitters. Germany’s natural gas infrastructure could be used immediately for methane storage. In addition to this immediately available solution, liquid fuels can be produced using hydrogen and CO2. All these methods can supplement battery electric vehicles.

How long will it take to set up the necessary energy infrastructure?

Kratzsch: It takes decades for a country to convert its entire energy supply. That’s why it is important to decide quickly about what kind of energy system we will have in the long term, so that we can then decide how to trigger investment in regenerative energy carriers for the transport sector.

But we still don’t know which kind of powertrains customers will choose in future.

Kratzsch: Powertrain concepts will succeed when they satisfy the mobility needs of the consumers, including availability and low specific costs throughout the whole life cycle. According to our investigations, there will probably not be any great difference in the life cycle costs for battery, fuel cell and plug-in hybrid vehicles once all aspects have been taken into account excluding taxes and charges, which are not yet known for the future.

But these are currently distorted by the pure tank-to-wheel view.

Kratzsch: Here again, regulation plays a crucial role. We urgently need a shift from viewing fleet emissions to a well-to-wheel analysis or even a life cycle assessment that takes account of all the emissions generated during the production process. The European Union is already discussing this for the period as from 2030. The timing itself is acceptable, but the important thing is to obtain certainty at an early point in the process to allow for the necessary investment in corresponding developments.

In this context, where do you see the focus of developments for battery electric vehicles?

Kratzsch: As far as all-electric vehicles are concerned, the focus is clearly on reducing battery costs. Volumetric energy density is an issue as well, which is why IAV is involved in the EMBATT consortium research project. And let’s not forget solid-state batteries which are currently the subject of intensive research by some manufacturers. Plug-in hybrids need to increase the C-rates, i.e. the maximum discharge rate in relation to the nominal capacity of the battery. Otherwise, smaller batteries remain comparatively expensive in the long term.

Do you think it makes sense to continue developing the combustion engine at the same time?

Kratzsch: For rural areas and inter-urban transport, we basically see two alternatives for climateneutral individual traffic: the fuel cell, which depends on setting up a hydrogen infrastructure, or the plug-in hybrid running on synthetic fuels. The same can also be said for road freight transport. It is therefore our aim to improve the mean efficiency of the combustion engine to such an extent that primary energy demand falls by a quarter. IAV is currently working on corresponding technologies.

While R&D funding for combustion engines is generally being cut back throughout the industry…

Kratzsch: That only applies to Germany! Japan is currently working on high-tech engines with a peak efficiency of 50 percent. Chinese customers meanwhile tell us they want an engine that is as efficient as the Japanese ones. In my opinion we must take great care not to lose touch with the world leaders. The same can also be said for university education: it is important to ensure there are no cuts in the professorships at institutes for internal combustion engines.

Which shares do you expect for which kinds of powertrain by 2050?

Kratzsch: It all depends on political decisions, technical developments and customer buying behavior. In reality we can expect to see mixed scenarios. We have developed a software tool called Mobility Synthesis in order to estimate the overall impact on energy demand and CO2 emissions from the transport sector. Basically, it is a consistent further development of Powertrain Synthesis, moving up to the next system level.

In December 2019 you’ll be hosting the Berlin Powertrain Symposium once again. What are your expectations this time?

Kratzsch: Our aim is to create a forum for dialogue between politics and business, which is why in 2019 we will be hosting the Symposium jointly with the VDA (Association of the German Automotive Industry). For us it is important that dialogue takes place not just between ministers and CEOs but on all levels involved in preparing legislation and investment decisions. Let me put it like this: you can get people to do almost anything once they have understood why it is important.

Mr. Kratzsch, many thanks for this interview!

The interview was conducted by Johannes Winterhagen

The interview was published in automotion 02/2019, the automotive engineering magazine of IAV. Here you can order the autmotion free of charge.