“How realistic is a Wind-assisted propulsion?” – Interview with Christoph Thiem and Martin Köpke
Within a dedicated Research and Development study, we are currently evaluating the potential of wind power as a possible decarbonization measure for our future fleet. We spoke with Christoph Thiem, Director Strategic Assets Projects, and Martin Köpke, Manager Regulatory Affairs & Sustainability, about their work on a concept to use wind-assisted propulsion on our container ships, the associated challenges, the pros and cons of using this kind of system, and the various ways they could be put to use.
Hello, Christoph and Martin! You both work on innovation-related matters. How important is research and development (R&D) to Hapag-Lloyd?
Christoph Thiem: R&D isn’t anything new at Hapag-Lloyd. Over the last few decades, the company has done a lot in this field, and we’ve always been an innovative shipping company. The pressure to innovate has significantly increased in recent years and, with it, the number of employees involved in innovation-related matters. There are also more and more possibilities, such as with fuels. In recent years, the spectrum there has been rather narrow, and it has been more about burning fuel as efficiently as possible. We are currently examining various fuels and alternative technologies on board our ships, such as harnessing wind energy.
Martin Köpke: While our industry aims to achieve net zero by 2050, here at Hapag-Lloyd, we’ve set ourselves the target of doing so by 2045. The challenge right now is fuel availability, and we won’t be able to tackle this challenge without R&D. What will drive us in the years ahead will be new alternative fuels. These aren’t available yet in the needed quantities and will initially be very expensive. That’s why energy efficiency and alternative technologies, such as using wind power to reduce fuel consumption, are important. Succeeding in these efforts will be crucial if we are to achieve our short- and medium-term goals by 2030.
Before motorisation, wind had been the standard means of propulsion in shipping for centuries. When did Hapag-Lloyd rediscover this concept?
Christoph Thiem: Hapag Lloyd has been working for some time on the issue of wind-assisted ship propulsion and how this could be realised in technical terms. But since this technology isn’t ready for the market yet, we think it’s important to expand our studies on it. We have found a suitable partner in the yachtsman Boris Herrmann and his Team Malizia, and at the beginning of the year, we launched a concept study for a 4,500 TEU ship with a state-of-the-art wind-assisted propulsion system.
We completed the first phase of the concept study in May. This has given us an initial impression of what this kind of ship could look like. In summer, we started phase two, which is still ongoing. We are using computer simulations to study how this kind of ship would behave under realistic weather conditions in a trade and how much energy we could save there with the support of a sail system. As part of this, we are also looking at the potential of weather-based route optimisation. On top of that, sensitivity analyses are being carried out. For example, we let the ship sail much more slowly in the simulation and then see how much energy we have saved. We also vary the draughts and see how the ship behaves when it isn’t fully loaded. And we are also investigating what happens if, for example, a sail is damaged or can’t be used.
Can you provide some more details about our concept?
Christoph Thiem: Our concept is a potential newbuilding of a ship with a capacity of 4,500 TEU. The current design envisages eight sails with a total sail area of 3,000 square metres. The six rear sails will be extendable, the two front ones retractable. This helps to not hinder cargo operations in port and to protect the sail system from damage as well as to avoid any limitations owing to things like bridges.
The container ship will mainly be propelled by its engine, and the sail system will only be used to assist propulsion. How much assistance the sail system can provide depends on a number of factors, such as the ship’s speed and the wind conditions. At slow speeds of 8 to 10 knots (15 to 20 km/h) and with the right wind conditions, the ship can also be propelled using just the sail system. But we haven’t explored all aspects of this yet. At the moment, we’re working with historical weather data for the Conosur service, which sails around South America. Next, we’ll be looking at other shipping routes to figure out how we could realise more benefits on other routes using this kind of sailing system.
To what extent are the various players in our sector working together on this issue? Is everyone pursuing a common goal, or is it more of a competitive thing?
Martin Köpke: A number of NGOs – including the Mærsk Mc-Kinney Møller Centre for Zero Carbon Shipping (MMMCZCS) in Copenhagen, the Global Maritime Decarbonisation Center in Singapore, and the Global Maritime Forum – are pooling their expertise. Shipowners, suppliers, energy providers, other NGOs and government agencies are working together to develop concrete solutions. When it comes to technical solutions, everyone is very eager to exchange experiences and ideas. For example, we recently sat down with Cargill (https://www.cargill.com/2023/cargill-bar-technologies-wind-technology-sets-sail ) at the MMMCZCS. They recently outfitted two ships with large sails. These are bulk carriers that use different sails than the ones we would because they have more space on deck. But we were able to exchange thoughts about the selection process. In one way or another, all the big and medium-sized shipping companies are assisting in efforts to find solutions that bring us closer to the net-zero goal.
What are you focusing on in terms of sustainability?
Martin Köpke: Our main goal is naturally to achieve our sustainability goals. Every tonne of CO2 we save is a good thing. We think it’s important to demystify wind propulsion. To do so, we need to educate people about the cost savings involved and the technology’s viability. How will this impact our operations? Will our crews need additional training? Which regulations need to be observed or even rewritten? In this case, our goal is to replace gut feelings with facts.
Christoph Thiem: In the future, instead of propelling our ships with fossil fuels, we want to use fuels that are produced using electricity generated by renewable energy sources, such as wind energy. But this will require a large number of facilities and processing steps when the fuel is produced and used on board. The result is that 90% of the original wind energy is lost before it even gets to the propeller. A sail system would ensure that the wind energy is directly harnessed and that some of this fuel is saved.
Ultimately, this is a matter of cost-effectiveness. If we spend more to buy and maintain the sail system than we save on fuel, there’s no upside to having a sail system. We aren’t sure how much these systems will cost, but they definitely won’t be cheap. Another challenge involves the physical space needed on board for a sail system. If we want do transport just as many containers with sails as we do without, we’re going to need a longer ship. And to propel a bigger ship, you need more energy. On top of that, we need to think about the flexibility of the routes. For example, routes with little wind would be unattractive for ships with sails. To sail efficiently with this kind of system, sailing schedules and arrival times would also have to become more flexible, which would be a downside for our customers.
Where will this research project go from here?
Christoph Thiem: We plan to finalise the concept study in the next few months, which will give us a basis for the next steps.
Martin Köpke: I’m often asked from people who aren’t in our sector why container ships don’t use sails. Our project is very important for gaining a detailed understanding of this kind of propulsion. And people also often assume that wind-assisted propulsion is free energy. But that isn’t the case, as it costs a lot of money. There are reasons why there aren’t a lot of container ships with wind-assisted propulsion. With this project, we are now gathering quantifiable data. At the moment, we assume that fuels from renewable energies will be expensive. But things may look different five years down the road, and then we’ll have to reassess whether the project is worthwhile.
About Christoph Thiem
Dr. Christoph Thiem, who holds a doctorate in marine mechanical engineering, has been with Hapag-Lloyd since April 2018. He got his start with the company as a project engineer and oversaw a number of retrofitting projects, including the one to equip our Dortmund Express-class vessels with scrubbers. At present, he is overseeing innovation-related projects at Hapag-Lloyd, such as the “Wind-Assisted Propulsion” project. He has been Deputy Head of the Strategic Asset Projects department since 2021 and will head up Fleet Innovation starting this coming February.
About Martin Köpke
Martin Köpke has been with Hapag-Lloyd for 10 years and currently serves as Manager Sustainability. He started in the Energy Efficiency department of the Fleet Support Center, where he worked on performance management to boost efficiency, among other things. He is currently on 80% loan to the Mærsk Mc-Kinney Møller Centre for Zero Carbon Shipping (MMMCZCS) in Copenhagen, where he works in the Energy Efficiency department. Before joining Hapag-Lloyd, he worked in the R&D department of the Hamburg-based classification society Germanischer Lloyd, specialising in energy efficiency. He studied mechanical engineering and shipbuilding at the University of Rostock.
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