As the European Union advances binding decarbonisation measures across transport, the role of e-fuels has become one of the most contested issues in EU energy and climate policy. Aviation is preparing for the gradual introduction of synthetic fuel obligations under ReFuelEU Aviation, while maritime transport faces a more fragmented transition under FuelEU Maritime, alongside difficult and unresolved negotiations at the International Maritime Organization. Across both sectors, debates over technological neutrality, scalability, and cost increasingly intersect with more fundamental questions about energy efficiency, resource allocation, and physical limits.
In this interview, Jutta Paulus, Member of the European Parliament, reflects on her path from science to politics and on how a natural-sciences background informs her approach to transport and energy legislation. She sets out where e-fuels are indispensable, where they are inefficient, and why policy choices must reflect thermodynamic realities rather than industrial or political convenience.
Q: How did you first become interested in politics, and in transport and energy policy more specifically?
I was already interested in energy issues at the very beginning of my political activity, when I was still at university and active in local politics. I ran for the Green Party shortly after the Chernobyl accident. In Germany, energy policy was already a major issue at that time, particularly because the country decided not to invest in new nuclear power plants.
Around 2000, when Germany passed its first renewable-energy legislation, I was among the first to apply for support. The scheme had been designed for a limited number of kilowatt-peak installations, but applications exceeded expectations. Authorities then limited support to the first five kilowatts, meaning that anyone wanting to install more capacity had to secure alternative financing.
I went to my bank with my calculations. They checked the numbers and confirmed that the tariff was guaranteed for 20 years, but they told me the return on investment was only around one percent and suggested there were better opportunities. My answer was that I was not doing it for the money. I wanted to do it because it mattered.
This context is important, because today there is often a narrative that Germany was wrong to shut down nuclear before coal. In 2000, a coal phase-out was politically impossible. The renewable-energy law and the nuclear phase-out were intrinsically linked. Without that legislation, which German taxpayers are still paying for, we would never have had the global expansion of renewable energy that we see today.
I stayed active in energy policy, founded an energy co-operative, and became more involved in the Green Party’s energy work. Eventually, after serving as the chief executive of a small laboratory, I decided at the age of 50 to move into politics full-time.
Q: How did you experience the transition from local politics to the European level?
When I decided to pursue politics professionally and became chair of the regional Greens, it was very clear that with my profile on energy, climate, environment, and biodiversity, the European Parliament was the place to be. That is where the decisive legislative files are shaped.
Q: What is your overall assessment of the role of e-fuels in the transport transition?
What is interesting is that in two of the legislative files I negotiated during the last term, I was actually the one pushing hardest for e-fuels. Others were more hesitant, arguing that the industry would not be able to cope.
In the sectors where we really need e-fuels, there is no viable alternative. You will never run a ship battery-powered from Shanghai to Rotterdam. It simply will not work. Yet those sectors are often the most reluctant. By contrast, in sectors where much more efficient, cost-effective, and reliable alternatives exist, such as road transport, there is strong pressure to rely on e-fuels.
This is often framed as technological neutrality. I am fine with technological neutrality, but it has to be based on physical reality. You cannot negotiate with physics, and physics does not care about political majorities.
You can try to slow down the transition, but it will inevitably come. We saw the same with renewable energy. What we are seeing now in the United States is that the only way to stop it is to legally forbid it from being built, because it has become so cost-effective. This is the last attempt of the fossil-fuel system to fight back.
Q: Why do you think there is such a discrepancy between sectors that need e-fuels and those that have alternatives?
Part of the explanation is scientific literacy. This may not sound very nice, but it helps to have a background in natural sciences. When colleagues argue that we simply need more innovation, my answer is that you will not find innovation in thermodynamics. You will not change the laws of thermodynamics. They were discovered in the nineteenth century, and no innovation will make e-fuels fundamentally more efficient.
There is innovation in batteries, in lifetime, materials, and charging speeds. These fields have really only been explored intensively over the last decade. By contrast, internal-combustion engines have absorbed decades of research, and any further efficiency gains are marginal.
It is true that we may find more efficient ways to produce e-fuels. But you still start with electricity, convert it into hydrogen, source carbon dioxide either from direct air capture or from biogenic processes, and then synthesise a fuel that can be used in existing engines. Each step involves energy losses. You cannot overcome that.
For many colleagues with backgrounds in law or economics, this is less intuitive. The other factor is that there is a large industry that has made good money from this system and wants to continue making that money for as long as possible.
Q: Do you think there should be more scientists in parliament?
You could always argue that parliament needs more people from one profession or another. You could say we need more sociologists, psychologists, or people with vocational backgrounds. What we really need is more diversity. At the moment, there are many people with legal or economic backgrounds and far fewer with backgrounds closer to everyday technical realities.
Q: In aviation, airlines argue that they cannot scale e-SAF and that conventional SAF is not yet available in sufficient volumes. How do you respond?
This legislation was agreed several years ago. The sector knew what was coming and what would be expected. It is the responsibility of the industry to ensure compliance by 2030. It is not the job of politicians, who already have to balance difficult compromises between political groups.
This is not about pleasing one political side or another. It is about keeping a habitable planet. If ticket prices rise, then so be it. If the climate crisis is not halted, we will see exploding food prices. That will be a much bigger problem.
Q: Maritime transport has several fuel options. Is that an advantage, or should the sector converge on one pathway?
Shipping is a global business, which makes fuel choices difficult. It is unfortunate that there has been such a rush to switch from heavy fuel oil to LNG. Significant infrastructure investments have been made, but LNG is still a fossil fuel, and methane emissions mean that, on a life-cycle basis, it can be no better than coal.
I would not go so far as to say politicians should decide which fuel to use, but policy must be science-based. My gut feeling is that methanol may prove the easiest transition fuel. It is liquid at ambient temperature, existing infrastructure can largely be adapted, and the risks are easier to manage than with ammonia. Infrastructure designed for heavy fuel oil cannot be used for e-methane or ammonia.
For me, it was no surprise that Maersk chose methanol. It would be helpful if other major players made similar decisions, because that would allow ports and supply chains to adapt.
Q: You supported allowing small ships to opt-in to EU maritime decarbonisation mechanisms. Why?
What I supported was not an obligation, but an opt-in. Compliance under EU maritime rules is calculated at fleet level, and operators can decide which vessels are included. My idea was that small operators could choose to invest early and build a business model around it, selling compliance credits to larger operators facing greater transition challenges.
Small and medium-sized enterprises are often more innovative and faster to try new approaches. At the same time, complex legislation is harder for them to manage because they do not have legal departments. Both sides of that reality need to be recognised.
Q: Europe may struggle to meet e-fuel demand domestically. How should production be addressed?
E-fuels have to come from somewhere, and I’m a bit divided on that. We need to speed up deployment; the more guardrails we set, the slower we will be. On the other hand, in countries where contracts have been signed for green hydrogen, such as Namibia and Morocco, it seems there is not much more work to be done.
Does it make sense to produce e-fuels in countries that still rely on fossil fuels and are under water stress? No, and ideally, the industry itself would consider where it is most appropriate to produce these fuels and where they could add local value.
More broadly, the global South is also bearing a larger share of the burden of climate disruption while being much less responsible for it, and we are not even letting them participate in producing and benefiting from the solution.
Q: What is your assessment of what happened at the IMO, and what should the EU do next?
What we saw at the IMO was quite unprecedented. A country walked in and more or less openly threatened not only countries, but the negotiating people personally, telling them that if their families wanted to travel to the United States, they should maybe behave differently in those meetings. Where are we? That was shocking.
They will do it again, in other negotiations and at other opportunities, because this government, the United States, is basically a puppet of the fossil-fuel industry.
The first thing the EU has to do is stick together. When member states abstain, as Greece and Cyprus did, it is extremely dangerous. On a global level, the EU is small. The only way to have influence is to act together.
Second, the EU and its member states should pursue bilateral co-operation with countries in the Global South. The former German government did this successfully by providing public guarantees to lower financing costs for renewable projects, combined with technology transfer. This kind of co-operation did not cost much money and was highly effective. That is the model the EU should follow, potentially extending it to trade policy as well.
Q: What final message would you leave with readers?
Make sure policy reflects the laws of nature. Without nature, there will be no civilisation
