Wind Propulsion: the Numbers Shipowners Can Finally Use
For a decade, wind propulsion made its case with scale models, simulations and promises. That changed over the summer of 2026. Between Chesapeake Bay and Halifax, the crew of the Neoliner Origin shut down the main engines for several days; in Japan, a tiltable rigid wingsail was fitted to a 60,000 dwt Ultramax bulker that went straight back into commercial service; on the slipway, the hull blocks of the co-operatively owned container ship Miaraka were welded into mega-blocks. Three unrelated scenes, telling the same story.
For a technical director or a superintendent, that shift is not measured in press releases. It is measured by the quality of the data available when an investment case has to be built. And this is precisely where autumn 2026 marks a turning point, since real-world operational feedback is starting to replace supplier projections. The question is what those figures actually establish, and what they still cannot settle.
Key figures
More than 100 vessels are now fitted with wind propulsion systems or classed as wind-ready, representing over six million dwt and more than 230 installed systems, according to the International Windship Association, which reports a near-tripling of the fleet since 2024.
78% fuel saved, or 17 tonnes, on one Chesapeake-to-Halifax leg of the Neoliner Origin, against an equivalent ship without sails at the same commercial speed. The widely quoted 89% figure refers to a different baseline.
16.6 knots through the water under sail alone, a new record for the vessel, up from 15.5 knots in March 2026.
EUR 9 million of Horizon Europe funding for the AWESOME project, whose purpose is to deliver performance data and standardised measurement methods.
EUR 21.4 million awarded to six projects in the second round of France's CORIMER low-carbon vessel programme, among them the Grain de Sail 3 sailing cargo ship.
The installed fleet has passed the hundred-ship mark
Wind propulsion is the use of wind as a source of thrust for a commercial vessel, either as main propulsion or as assistance to a conventional engine. Long a niche subject, it now rests on a fleet large enough to be discussed in fleet terms rather than as a set of prototypes. On the Wind Ship collective stand at SMM Hamburg in early September, the secretary general of the International Windship Association, Gavin Allwright, reported 116 wind-powered vessels in service, twelve more ready to enter service and around a hundred further units on order. Those orders of magnitude are consistent with the association's own spring count, which recorded more than a hundred ships fitted or prepared, over 230 installed systems and slightly more than 100,000 tonnes of CO₂ avoided per year.
These figures come from a trade association whose members supply the technology, and should be read accordingly. They nonetheless describe a shift that is hard to dispute, since the fleet has almost tripled in two years and orders are now placed in batches: Union Maritime has signed the largest to date, covering 34 vessels. The question facing technical departments is therefore no longer whether the technology exists, but whether it fits inside a maintenance plan and an operating budget.
Retrofits have left the prototype stage
It is on retrofits that the year offers the lesson most directly transferable to an existing fleet. On 25 August, OceanWings announced that installation of a tiltable rigid wingsail had been completed aboard the Maria Topic, a 60,155 dwt Ultramax bulker operated by Italian owner Ant Topic. The work, carried out at Japan's Tsuneishi Shipbuilding with support from the European WHISPER project, is a first on this vessel type. More to the point, it was delivered on schedule and the ship resumed her commercial trading without interruption: for a superintendent, that matters more than the headline performance, because off-hire remains the largest cost item in any retrofit. As Emmanuel Schalit, chief executive of OceanWings, puts it, the project demonstrates the company's ability to deploy innovative solutions at scale while meeting owners' operational requirements. The vessel has since been trading transpacific, and the first operational feedback was presented at SMM. A second demonstration, on a container ship operated with Samskip, is planned under the same project.
Two other programmes are advancing in very different segments. Airseas completed the first at-sea deployments of its 250 sq m kite this summer aboard the Cape Brolga, a K Line Capesize bulker on the Japan-Australia run, with a 600 sq m wing as the next step. Beyond the Sea, meanwhile, has joined forces with the STS joint venture formed by SBM Offshore and Technip Energies, and with TotalEnergies EP Suriname, to fit a SeaKite® 2400 to the GranMorgu FPSO and cut fuel burn during her tow from China, the partners citing an average saving of around 20% for this engine-and-kite combination. The programme is deliberately phased, with technology qualification and onshore testing before integration. Decarbonisation is one of the group's strategic priorities, notes Laurent Le Touze, group technology and product development director at SBM Offshore. The wider significance lies elsewhere: the case extends wind assistance into heavy offshore, a segment where units do not lend themselves to conventional rigs.
Newbuild orders are shaping an industrial supply chain
Newbuildings follow a different logic, that of ships designed around the wind from the outset. Four French programmes now define the offer.
Miaraka (Windcoop): a 91-metre, 210 TEU container ship driven by three automated rigid wings from Computed Wing Sail totalling 1,050 sq m, at an estimated cost of EUR 28.5 million, of which nine million was raised from some 2,500 co-owners. The hull blocks were joined into mega-blocks this summer, ahead of a launch announced for December and a direct Marseille-Madagascar service.
Compagnie Maritime Nantaise ro-ro: a 105-metre vessel dedicated to space logistics, ordered on 21 August from Guangzhou Shipyard International, designed by Knud E. Hansen and VPLP and fitted with three OceanWings wingsails. After the Canopée and her four sails, this is France's second wind-powered newbuild for launcher transport, with entry into service targeted around 2030.
Grain de Sail 3: selected among the six winners of the second CORIMER low-carbon vessel round, worth EUR 21.4 million and run by ADEME on behalf of the French state under the France 2030 plan. Developed with Chantiers de l'Atlantique, the project covers a 165-metre container ship able to carry in the order of 570 boxes, with operations envisaged from 2029.
Atlantis (NEWTOWT): the third Phoenix-class sailing cargo ship, delivered in early August by Piriou, 81 metres long and able to carry 1,100 tonnes of cargo. She has sailed for Brazil ahead of a maiden call at Le Havre expected in November, while the Atlas, fourth of the series, is completing fit-out.
Less visible milestones matter just as much for what comes next. Computed Wing Sail continued testing its Airfin350 wing at Saint-Nazaire in July, working on a difficulty specific to asymmetric wings, namely their ability to take the wind on either tack, and appointed a managing director, Étienne Delcroix, who took office on 1 September. The VELA1 trimaran, designed by VPLP, showed her bow at the Austal yard ahead of a delivery announced for the end of the year. The pattern is that of a sector acquiring management structures and industrial capacity, not merely demonstrators.
What is still missing: comparable data
That leaves the central obstacle, the one that stalls decisions in investment committees: the absence of a shared method for measuring a wind-assisted saving. This is the purpose of AWESOME, funded with EUR 9 million from Horizon Europe, led by Kongsberg Maritime and bringing together fifteen European partners, including four Wind Ship members, Chantiers de l'Atlantique, Mauric, Neoline and Syroco. The programme does not fund a technology; it funds the production of real-world performance data, decision-support tools and standardised methods.
Two demonstrators contribute to it. A 49,000 dwt Odfjell chemical tanker, retrofitted with four 22-metre bound4blue eSAIL suction sails, already reports savings of around 20% on selected voyages, while the Neoliner Origin, with her two 76-metre SolidSail rigs, targets emission cuts of up to 80%. It is that same ship which produced this summer's most discussed sequence: leaving Chesapeake Bay for Halifax in late June, the crew shut down the engines and let 3,000 sq m of sail drive 136 metres and 11,000 tonnes for several days. Neoline reports a peak of 16.6 knots through the water, an average of 11.2 knots over the ground, a commercial speed of 9.3 knots once weather routeing is accounted for, and 78% of fuel saved, or 17 tonnes, against an equivalent ship without sails at the same commercial speed.
The 89% figure, more striking and more often repeated, rests on a different baseline: a conventional ship steaming at 15 knots. That distinction is not a communications nicety, because it determines the regulatory value of the saving. An owner can only set a saving against FuelEU Maritime, or against the carbon framework being built at the IMO, if the measurement follows an accepted method and rests on traceable data. We have looked in detail at what the IMO's new carbon framework changes for shipowners and at why ships in service remain the blind spot of maritime carbon accounting.
Wind propulsion is also an operations problem
A wind propulsion system is not simply an area of sailcloth. It adds actuators, sensors, controllers and control laws to a ship that already had plenty of them, and it adds as many lines to the maintenance plan. The Maria Topic retrofit illustrates the point in its own way, since wing performance matters, but the ability to maintain that wing without taking the ship out of service matters more over time. Owners preparing an installation therefore face three workstreams quite separate from the choice of supplier.
Maintaining the wind propulsion system, which belongs inside an existing preventive plan rather than being tracked separately, failing which the work is discovered in port. Our guide to preventive ship maintenance sets out the method, including the link with port state control detentions.
Competence on board, which the sector is beginning to organise: the CAPVENT training project is led by Nantes Université, and Wind Ship is working with CINav on the B-SEA project, due in October 2027.
Traceability of operational data, the precondition for any performance case and for any regulatory filing, whether under the ISM Code or carbon reporting.
That third point is the least spectacular and the most decisive. A wind-assisted saving is demonstrated with running hours, consumption figures, weather conditions and positions, collected on board in a consistent way, voyage after voyage. Many operators still approach this with a spreadsheet and a paper log book, which is enough to trade a ship but not to document a multi-million-euro investment. This is where maritime maintenance software and a digital log book stop being an administrative convenience and become an instrument of proof. The market grasped this before the regulators did, which is why it is moving towards the single suite rather than towards a stack of tools. Selection criteria differ with fleet size, whether for a ten-ship fleet or a larger merchant fleet; our complete guide to choosing maritime maintenance software sets out the evaluation grid.
A sector now judged on its evidence
The thread running through this autumn is therefore less technological than informational. Wings, kites and rigs work, and the installed fleet is now large enough to judge them; what is being built project by project, and voyage by voyage, is the body of data that will let a technical director defend a retrofit in front of a finance director. The sector meets again on 23 October in Saint-Malo, alongside the Route du Rhum, then on 16 and 17 June 2027 in Saint-Nazaire for the fourth edition of Wind for Goods. Until then, the useful question for an owner is not which technology to pick, but whether the operation is capable of measuring what that technology delivers.
BoatOn Book brings the log book, the maintenance plan and a vessel's carbon footprint together in one tool, so that operational data is available when the decision has to be made. You can explore the modules or estimate the return on investment for your fleet.
Sources
MarineLink, rigid wingsail retrofit completed aboard the Maria Topic
SBM Offshore, wind-assisted towing agreement for the GranMorgu FPSO
Ship & Bunker, IWSA count of the global wind propulsion fleet
Splash247, Compagnie Maritime Nantaise orders a wind-assisted space logistics ro-ro
Mer et Marine, six projects selected under CORIMER low-carbon vessels
Illustrative photographs: Pexels, free licence. They do not show any of the vessels mentioned in this article.
