Wind Propulsion: Reinventing the Art of Navigation

By Colomban Monnier – Chairman of the Management Board of the ENSM Foundation

Long regarded with polite nostalgia, wind-assisted propulsion[1] has, in just a few years, become one of the most dynamic segments of maritime R&D. Driven by economic pragmatism and climate urgency, it is transforming ships into complex hybrid systems. For deck officers and naval architects alike, this marks the advent of a new technical era.

This is no longer “sailing” in the traditional sense, but applied industrial aerodynamics. Automated rigid wings, Flettner rotors exploiting the Magnus effect, traction kites, suction-based airfoils… solutions are multiplying. These technologies can deliver fuel savings of between 5 and 20% when retrofitted to existing vessels, while newbuilds now target over 50% decarbonisation through wind power — and up to 80% for next-generation sailing vessels. With nearly 70 large commercial ships already equipped worldwide and an order book growing rapidly, wind has once again become a “serious” energy source.

An integration challenge for naval architects

Integrating these systems into commercial vessels is a fascinating engineering challenge, as it requires rethinking the ship’s very structure. Modern wind-propulsion devices generate significant thrust and heeling forces, which must be absorbed by dedicated deck reinforcements. Ship stability must be recalculated to account for these new overturning moments, leading to changes in conventional IMO stability criteria.

For young naval architects and structural engineers, this represents a vast field for innovation. Ships must now be designed as “Wind-Ready”, capable of accommodating these systems without compromising cargo operations (watch out for gantry cranes and deck layouts) or bridge visibility.

A renewed role for deck officers

The most profound transformation, however, is taking place on the bridge. With wind propulsion, the ship becomes a truly hybrid system. Wind is a free but variable source of energy. The officer of the watch can no longer simply follow a fixed course and heading; they must become an energy strategist.

This represents a tremendous opportunity for cadets and young officers. Their profession will gain a real-time performance analysis dimension. Decisions will have to be made: is it more efficient to deviate from the shortest route to seek favourable winds, or to remain on the direct track under engine power? How should wing incidence be adjusted to maximise thrust without increasing leeway? Weather-routing software is becoming as critical as radar, and mastering these tools will be essential for the officer of tomorrow.

Regulatory recognition changes the game

Wind energy will be fully taken into account in IMO[2] and EU compliance calculations. As a zero-emission energy source, it mechanically improves a vessel’s carbon footprint. For future fleet managers, mastering wind-assisted propulsion therefore becomes a direct financial lever to reduce carbon-related taxes[3].

Far from being a step backwards, wind propulsion is a cutting-edge technology that requires advanced skills in fluid mechanics, structural engineering and meteorology. For the new generation of seafarers and engineers, it promises technical, operational and intellectually stimulating maritime careers, fully aligned with their aspirations.

[1] WAPS: Wind Assisted Propulsion Systems

[2] CII: Carbon Intensity Indicator

[3] EU ETS: European Union Emission Trading System