Shipping faces growing pressure to reduce emissions as international and European regulations tighten. Wind-assisted ship propulsion (WASP) offers one near-term response, but performance can vary significantly because wind close to sea level is turbulent and affected by waves, thermal gradients and the vessel itself.
Swiss company WindTracX SAGL is approaching the problem from above. Its Dragonfly Aero Kite Drone is designed to fly more than 250 m above the sea, using controlled crosswind flight to provide supplementary propulsion while potentially supporting weather intelligence and maritime surveillance.
Going above the turbulence
The Dragonfly launches vertically from a pivoting station at the ship’s bow before climbing to altitude on a high-strength Dyneema tether.
Rather than drifting passively, the rigid-wing drone flies controlled figure-of-eight patterns. Its movement generates apparent wind, increasing aerodynamic lift and transmitting traction through the tether to the vessel.
The system combines:
WindTracX says the rigid-wing design also avoids the collapse risk associated with soft fabric kites. Previous test flights have operated under approval from the Swiss Federal Office of Civil Aviation (BAZL), including fully autonomous modes.
Targeting fuel consumption
WindTracX plans systems ranging from 25 kW for smaller vessels to 1 MW for large bulk carriers and tankers.
For a 50,000 DWT vessel, the company’s modelling projects average annual fuel savings of approximately 5%, rising to 15% on optimal routes. It estimates this could equate to annual savings of $700,000 to $1 million per vessel, with a payback period of three to five years.
These are company projections rather than independently verified operating results and will depend on vessel type, route and wind conditions.
The commercial case is being strengthened by regulation. Shipping accounts for nearly 3% of global greenhouse gas emissions, while the International Maritime Organization’s Carbon Intensity Indicator (CII), FuelEU Maritime and the EU Emissions Trading System are increasing pressure to improve operational carbon performance.
More than propulsion
Once airborne, the Dragonfly could provide other functions alongside propulsion.
WindTracX has signed three letters of intent covering weather data, surveillance and insurance applications. The proposed capabilities include:
A collaboration with Omenic.AI would integrate meteorological equipment into the drone. WindTracX argues that measurements taken directly at altitude could improve routing decisions and provide a clearer picture of the system’s contribution to fuel reduction.
A second agreement with Abintel Sagl covers cameras and optical sensors, while a third with a Helvetia insurance consultant explores whether improved weather routing, incident prevention and documented performance could contribute to lower marine risk.
From prototype to commercial deployment
The technology is currently at Technology Readiness Level (TRL) 5. WindTracX reports that a fully functional 1.5 m prototype has completed multiple hours of autonomous flight.
Its development roadmap targets:
The company says it has also filed two Patent Cooperation Treaty (PCT) applications with the European Patent Office.
The concept has been developed around both a rigid-wing prototype and a proposed maritime application, with the kite operating from a vessel at sea.
WindTracX is targeting bulk carriers, general cargo vessels, RoRo ships and tankers between 10,000 and 60,000 DWT. The company is seeking CHF 5.2 million in staged investment over three years, with the aim of achieving its first commercial installation in 2027.
The concept remains at the development stage, but its proposition is distinctive: move wind-assisted propulsion away from turbulent deck-level air and use the resulting airborne platform for more than traction alone.
Read the full Industrial Insight feature on airborne wind-assisted propulsion, weather intelligence and maritime surveillance from WindTracX SAGL in PES Wind: https://pes.eu.com/exclusive-articles/above-the-surface-how-airborne-wind-could-support-shippings-decarbonisation-future