Interview with Mr. Gavin Allwright, Secretary General of the International Windship Association (IWSA)

By Longyu Xue, China Ship Survey

June 2026 saw the global fleet of wind-propelled cargo ships officially surpass the 100-vessel milestone, with over five million deadweight tonnes (DWT) of cargo capacity, following the latest round of wind propulsion system installations on large commercial vessels. What was once widely regarded as a niche or historical form of marine propulsion is now rapidly emerging as one of the practical decarbonisation solutions gaining momentum across the shipping industry.

Commenting on the milestone, Mr. Gavin Allwright, Secretary General of the International Windship Association (IWSA), said that reaching the 100-vessel mark represents an important market marker for wind propulsion technology. As manufacturing scales up and installation experience grows, particularly if fuel prices remain elevated, the return-on-investment timeframes are expected to continue shortening, further strengthening the appeal of wind propulsion for shipowners. However, he also emphasised that “we can go further and faster”, calling on the industry to focus on scaling deployment towards the goal of 1,000 vessels and beyond.

In a recent exclusive interview with China Ship Survey magazine, Mr. Gavin Allwright shared his insights on key industry topics, including the growth drivers of wind propulsion, the choice between retrofit and newbuild pathways, technology evolution trends, operational optimisation potential, and the role of wind in global shipping decarbonisation and regulatory compliance. During the interview, Allwright elaborated on the tangible value of wind propulsion in reducing fuel costs, meeting environmental regulations and enhancing energy security. He analysed the reasons behind the early lead taken by tankers and bulk carriers, as well as the challenges facing segments such as container ships. He also expressed strong expectations for the key role of China’s maritime community in the global wind propulsion value chain and the prospects for deeper cooperation going forward.

Mr. Gavin Allwright, Secretary General of the International Windship Association (IWSA)

Q: The number of large commercial vessels equipped with wind propulsion systems has increased nearly fivefold over the past four years. What do you see as the key drivers for sustaining such rapid growth momentum going forward?

A: As with all innovation and equipment dissemination, there are some bottom-line drivers that help maintain rapid growth. These include high prices for the alternative (i.e. fossil fuels and incoming alternative fuels), the continued lowering of costs and price of the product, through economies of scale, a steady supply chain and increased capacity for installation. The appetite for shipowners to lower operational costs, through lowering fuel costs and investment into equipment with relatively quick ROIs is also vital. To maintain that investment appetite, we need a generally predictable geopolitical situation and a clear regulatory pathway forward, both of which are rather challenged currently.

From a wind propulsion specific perspective, then to maintain this growth we also need standard approaches to evaluation and validation, which are being developed. The aggregation and anonymization of that performance data also help the market to assess the technology segment and the systems on offer, and this will be increasingly possible in the next year or so. There are of course many other smaller drivers, but the final significant one is that yards increasingly add wind propulsion systems to their makers lists and offer these to customers as standard equipment rather than bespoke.

Q: Wind propulsion technology is applied both as retrofits to existing ships and increasingly integrated into newbuild designs. Over the next few years, what respective roles will the retrofit and newbuilding markets play in the industry’s growth? What are the main factors shipowners weigh when choosing between these two paths?

A: As with all things ‘shipping’ it is rather challenging to generalize across many sectors, the factors considered by say a cruise or container line operator will be significantly different than those considered by tanker sector or for offshore vessels. Having said that, there are some general points that all shipowners will consider – cost, ease of installation, performance and regulatory compliance.

From a cost perspective, it will usually be lower cost to do any reinforcement work and foundations, cabling etc. in a newbuild project, and we see some that coming through in making ships ‘wind-ready’, especially at the lower level of reinforcement/design and evaluation. Ease of installation follows a similar pathway, when it is easier to install when a vessel is being built, however this is marginal when foundations have already been set (as in higher level wind-ready) or the shipowner has chosen a more modular approach, where all ships in the fleet have foundations and the units themselves are then move between ships. There is a still pervasive myth that a wind installation is a relatively permanent fixed asset, like an engine system and this is a misconception, indeed units can be easily removed and reinstalled in a matter of hours or a few days for more complex systems.

When it comes to performance, then a ship designed and integrated with wind will likely be the one where you will get the best performance out of the wind system and the ship. If it is to be an optimized wind-assist delivering 20-30% propulsive power from wind or a primary wind vessel, delivering 50-80%, then the newbuild pathway will be the natural one to follow.

Regarding regulatory compliance, then retrofit is a very important pathway, as many existing ships have few energy pathways to compliance with say emissions regulation. If you are able to add wind propulsion (10-20%) to energy efficiency gains (c.20%) and operational optimization, (c.20%) then you can really start to make a dent in ETS charges but also lower the energy intensity of the vessel in FEUM or the IMO GFI calculations. Fuel EU is already the case that with 15% wind propulsion installed, then a 5% reward will be available, ensuring that ship would effectively be compliant (using banking or pooling) until the mid-2030s, avoiding US$1200 per ton of fuel charges.    

Q: Tankers and bulk carriers currently account for the largest number of vessels equipped with wind propulsion systems. What are the main reasons these vessel segments are leading adoption? Conversely, what factors are limiting the wider uptake of wind propulsion across other vessel types?

A: Bulkers and tankers both have a fair amount of deck space for deck installed wind systems, so they have been a relatively lower hanging fruit for installation. These vessels also burn a lot of fuel and are relatively slow which means that performance of wind propulsion can deliver quite well for these, especially on longer cross ocean routes. There is also the innovation staple that when a sector delivers 3-5 reference vessels using a particular technology that this enables easier assessment in the market and this ‘critical mass’ has been reached through first mover shipowners and technology providers, thus generating some significant momentum there.

Most other segments are approaching this ‘tipping point’ but it takes time to cascade through those segments, especially if they are dominated by smaller operators, such as general cargo or to a degree the RoRo cargo segment. 

The container ship segment is a challenging one, as deck space is at a premium and when fuel prices are held artificially low (real price of fossil fuel is 3-4x current levels if all externalities are fully costed), then the trade off of wind propulsion and cargo space is rather challenging. Technically and operationally however, systems can certainly be incorporated at build on these ships, and there are a number of design projects underway. With off-deck systems such as kites or some other options, the retrofit of wind systems could certainly be considered too

Q: In recent years, the industry has developed a range of wind propulsion solutions. How do you see wind propulsion technology evolving in the future? What room for optimisation remains in terms of efficiency, cost, and vessel compatibility, etc. for the technologies?

A: Unfortunately, I don’t have a crystal ball, however we can see some parallels with other sectors, and we can get some indications from the pipeline of technologies coming through.

Firstly, the development of a number of different wind technologies is a really positive element for the technology segment, this keeps internal competition strong and that feeds into upgrades, optimization and the lowering of costs and ultimately prices over the mid- to long-term. It does of course bring some challenges on system selection, but each technology has particular strong benefits and there is an element of ‘horses for courses’, where two or three systems will likely match the criteria for each vessel, and then as the market matures further, decisions will continue to be made on performance, validation etc. but also upon availability, servicing agreements and on the colour you like (joke!)

We are still in the first decade of deployment and only the first few years of early scaling, so if we look at the offshore wind sector, we have seen truly incredible scaling in power, material and engineering developments and cost reduction in this field, wind propulsion is likely to follow that path.

From a pipeline perspective, there are a lot of technology innovations and new design ideas coming through and we are likely to continue to see more protypes and ships coming through in the next few years. That healthy pipeline indicates that engineers and designers see additional scope for optimizing and leaning into the potential of wind.

With existing systems, these have been proven and as they scale, costs will fall precipitately and production capacity is already in the high hundreds, so supply should not be a problem. 

Q: In real-world vessel operations, what are the key factors affecting wind propulsion performance? What measures can be adopted to maximize its effectiveness?

A: I am not an engineer, nor an operator of wind installed vessels, however the main factors that affect wind propulsion performance follow the answers to these questions;

Have you selected the appropriate system for your vessel and sighted those units well? Is your vessel on a good route for wind and/or can you use wind-routing software that can substantially improve the performance? Is the wind system well integrated into your energy management system, therefore optimizing engines when the ship receives fluctuating amounts of wind power? Are your crew and management well familiarized with the operation and maintenance of the systems?

If a ship owner is answering these key questions and works with the technology provider to ensure that these are answered positively, then you will be getting the best out of your wind systems.  

Q: The shipping industry is currently exploring diverse decarbonization pathways, including clean alternative fuels and electrification. In comparison, what unique advantages does wind propulsion offer? What role will it play in the future global maritime energy transition?

A: The unique sales points for using wind are multiple, and I will focus firstly on this as an energy source in the list below

Wind energy is….

·         Zero emissions – all emissions, not only carbon (including climate impacting H², N², CH⁴, BC, VOCs, URN etc.)

·         Zero cost – free energy forever

·         Zero infrastructure

·         Zero onboard storage

·         Zero pollution or fire risk

·         Globally available and abundant

·         Supply open to all – global commons

Wind propulsion technologies are…

·         The only energy pathway technology that will pay for itself

·         Adding range and a degree of energy security to your fleet

·         Relatively low carbon footprint and embedded carbon/energy

·         Low maintenance & Easy to understand

·         Mostly automated and require no additional crew

·         Low risk of fire, non-toxic, relatively low safety concerns

What role will it play in the future global maritime energy transition? This is a really a matter of choice – could wind propulsion become the primary energy pathway for future shipping – yes, it could. We have the technology, understanding and materials to build wind into all vessels, retrofitting all ships to a 20% level in the next 5-10 years is very doable. Then all new ships are either designed as optimized wind-assist [30-50%] or primary wind [60-80%] and these are supplemented by a basket of electric, liquid or gaseous fuels. However, we could also take that paradigm further, how about utilizing all of the wind power that we fail to harness, and capture that and convert that onboard as a fuel, then we start to move into a ‘perpetual motion’ situation, or could we call that a truly ‘autonomous energy ship’

The latter part is of course blue sky thinking, however there are projects working on these concepts and we have a number of large yachts and research vessels generating in this way.

However, if we stick to more conservative assessments, then it is completely possible to reduce dramatically the amount of low carbon commoditized fuel that we need to reach a net-zero goal in the 2050s. Indeed, I would suggest that we can’t get there without substantial roll out of wind, coupled with a strong emphasis on energy efficiency and voyage optimization. If we only need to supply 20-40% of the current fuel demand by the 2040’s, then that is a very different nut to crack. 

Q: As a key industry association connecting wind propulsion technology developers, research institutions, and the wider shipping community, IWSA has undertaken extensive work in technology promotion, standard-setting, industry exchange, and policy engagement. What areas will IWSA prioritize in the coming years?

A: All of those areas need continued efforts, especially in standard setting and policy advocacy areas. Wind propulsion is the oldest (cleanest) way of moving ships, but it has been out of the mainstream for a long time. This means that there is a segment of the industry and external stakeholders that are still reticent, resistant or simply unengaged, so it is vital to keep moving on all fronts, but especially integrating wind propulsion into the technical, operation and compliance frameworks. The integration of wind as an ‘energy source’ rather than an ‘energy efficiency’ is particularly important at a policy level as there is a very strong tendency to see unaffordable alternative fuels as the target for subsidies or special treatment, leaving wind energy unsupported and actively biased against.

We also want to have standard approaches that treat wind fairly adopted in the legal, insurance and contractual areas, thus leveling the playing field and enabling shipowners to fully unlock the potential of wind.

Over the next two years we will be involved with the development of IMO interim guidelines for wind propulsion safety and training, and these will help to ensure some of that level playing field continues to develop.

Q: Standing at the milestone of 100 vessels and looking toward a future with 1,000 or more vessels, as Secretary General of IWSA, what are your expectations and recommendations for stakeholders across the global industry chain?

A: It is an interesting feeling, we rarely stop to take stock – we have waited for a decade to reach this buoy maker on the wind propulsion channel and yet as we hit it, our members are already way past that point and preparing the ships for the next hundred, signing the contracts for the next and laying the foundations for the next wave.

My expectations are that wind propulsion will go mainstream in the next couple of years, be the go-to propulsion energy option well into the 2030s and will become a no-brainer option for all shipowners shortly afterward. The UK government assessed that wind propulsion would be installed on 40-45% of the world fleet by 2050, I think that is conservative and could be far higher.

I am not sure that I am in the position to recommend any course of action in a global industry with all of the expertise there. I can, however, ask a few questions:

Que 1. Is there another energy option that has all of the benefits listed above, with technology that is available off the shelf now and that will deliver an element of energy security and make your fleet both compliant and save money? If there is, then I would implement that alongside wind on every vessel in my fleet.

Que 2. Can we wait to act on future proofing the global fleet until we have a certain regulatory framework, geopolitical stability or a lull in the environmental drivers? If not, then we need to act on the low hanging fruit right now, wind, energy efficiency, crew training, digitalisation and voyage optimization all pay for themselves.  

Que 3. It is time to choose ----- which colour would you like?
 

Q：How do you view the potential for wind-propelled vessel applications in the Chinese market? In which areas can IWSA and China’s maritime community further strengthen exchanges and cooperation?

A：China is a central shipbuilding and unit production powerhouse, and this sector holds a huge growth potential. However, it is also true that China is a key owning/flagging nation and therefore mandating wind ready for newbuilds for the domestic fleet would be a significant step, as would increasingly adding wind propulsion systems (both domestic and foreign producers) to standard equipment lists in Chinese yards.

In the realm of strengthening exchanges and cooperation, sharing the experiences of Chinese shipyards in installations and the research that is underway in maritime research centres will be a great boost to the sector as a whole. We currently have a call for abstracts open for our next Wind Propulsion conference to be held in Singapore in April 2027, with a strong emphasis on Asia-based research and experience, this will be hosted by Royal Institution of Naval Architects (RINA) and IWSA. We also hope to organize more events and opportunities to exchange experiences in China in the coming years and we are open to discuss possibilities to push that agenda further. Finally, a great way to help foster further cooperation is to join our association as a member. We have a small group of Chinese companies as members or registered supporters, and you will be most welcome if you would like to join the other 200+ members to help shape the future of wind propulsion together.