More than 90 percent of global freight transport takes place by sea – making shipping responsible for around three percent of worldwide greenhouse gas emissions. The UN specialised agency International Maritime Organization (IMO) has therefore defined binding emission targets. With interim targets for 2030 and 2040, international shipping fleets must operate climate-neutrally by 2050. This legal requirement is forcing the maritime industry into a radical change of course and raises pressing questions: How do global shipping companies navigate the green transformation? And what role could the return of wind propulsion play in the decarbonisation of the world's oceans? Two lectures as part of the Future Lecture explored possible answers.
Vice President for Research Prof. Irina Smirnova welcomed the audience in Audimax II to the now thirteenth edition of the Future Lectures. It was organised in cooperation with the TUHH research focus (FSP) Maritime Systems. The spokesperson of the FSP, Prof. Sören Ehlers, emphasised: "The guest speakers of the Future Lecture impressively demonstrate the future prospects of a shipowner, in particular the technological possibilities for decarbonisation through wind propulsion. This is highly relevant, because it still holds true: 'no shipping, no shopping'."
Ships are to sail completely climate-neutrally by 2045
Silke Lehmköster, Fleet Director at Hapag-Lloyd AG, which operates the world's fifth-largest container shipping fleet with around 300 ships, made the connection to practice. In her lecture, she made clear that the maritime industry is in one of the most significant technological transformations in its history. Climate goals, environmental regulations and geopolitical crises are forcing shipping to plan far-reaching investments in an uncertain market environment. To meet this uncertainty, in addition to new fuels and smart newbuilding and retrofitting programmes, technological innovation is needed – and the people who produce it: "When I was looking for a new head of the Fleet Innovation & Newbuilding division," Lehmköster recounted, "I realised that there are no longer so many people here in Germany with a shipbuilding background. And to put it quite openly: I need them. I need people who look ahead. I need innovation."
Following the 1.5-degree target of the Paris Agreement, the company is aiming for a 30 percent reduction in CO₂ by 2030. By 2045, that is five years ahead of the IMO target, it even intends to operate completely climate-neutrally. To achieve this goal, the shipping company is relying on various measures. These include comprehensive ship conversion projects, (digital) technologies to increase efficiency, dual-fuel propulsion systems and alternative fuels. To secure the availability of alternative fuels such as green methanol, the company has, for example, concluded long-term supply contracts with energy corporations.
Instead of focusing on a single technology or a specific fuel, Lehmköster posed a core engineering question: How can ships be designed, built and continuously adapted when the future energy landscape is still under development? In this dynamic context, technological flexibility and life-cycle thinking are among the decisive design principles, according to Lehmköster. Maritime engineering expertise remains of strategic importance for Germany. However, to preserve the innovation ecosystem of shipowners, shipyards, equipment manufacturers and universities, it is necessary to invest not only in technology but above all in the next generation of engineers.
Reinventing sailing ships
Since alternative fuels will be considerably more expensive than fossil fuels, the German innovation ecosystem is also called upon to develop solutions. One solution could lie, of all things, in one of the oldest energy sources of all: the wind. "Wind propulsion is a proven technology and it makes sense to use it, because wind is free," said Dr. Florian Kluwe, Managing Director of the engineering firm SDC Ship Design & Consult GmbH and a TUHH alumnus.
According to Kluwe, however, new or additional propulsion technologies also have fundamental effects on ship design itself: "We have to reinvent sailing ships. In doing so, I have to look at the sail systems themselves. I have to integrate them on board, find the right place, and I have to think about hull efficiency, since the sail systems change the forces acting on the entire ship." In his lecture, Kluwe gave an overview of current wind propulsion systems. These include so-called rotor sails, rotating cylinders made of light metal that stand vertically on deck and generate mechanical propulsion through over- and underpressure, or rigid sails, which function aerodynamically like the wings of an aircraft.
Since wind-assisted ships travel more slowly on average and have to adapt their routes flexibly via weather routing, this concept fundamentally collides with the precisely timed just-in-time delivery schedules of global maritime trade. For a liner shipping company like Hapag-Lloyd, however, such a system change is not an option. In the joint question-and-answer session, Silke Lehmköster countered that a departure from the just-in-time paradigm could not be conveyed to her stakeholders. Both perspectives made clear that the decarbonisation of global shipping cannot rely on a single technology. In addition, a compromise between economic constraints and ecological necessities must be continuously negotiated.
About the Future Lectures
In the Future Lecture series, researchers provide insights into their work and shed light on the technological and societal trends of tomorrow. The format illustrates the challenges facing society, industry and research, and the positive changes that TUHH research can bring about for society.
