Introduction:
Currently, wind-assisted propulsion systems have become mature technologies that contribute measurably to reducing greenhouse gas emissions and diminishing fossil fuel consumption.

These systems operate at high altitudes up to 300 meters, where winds are more favorable, being less affected by turbulence than sea-surface winds and stronger winds.

Given the wind patterns in the Black Sea basin, it is relevant to examine how such a system performs under these regional conditions during winter.

Method

This study audits a voyage in the Black Sea basin by a cargo ship equipped with a towing kite, utilizing data from the Copernicus Climate Change Service. Hourly wind components at 100 m altitude were sourced from the ERA5 reanalysis dataset.

The pulling force was predicted using an abridged approach based on aerodynamic lift and drag generated by the apparent wind speed acting on the kite area. The model vessel used throughout the work is a small cargo vessel with a tonnage not exceeding 10,000 DWT, cruising at about 11 knots, while the towing kite area varies from 160 to 320 square meters.

The novelty of our work stems from using hourly wind data across successive Black Sea voyage legs to improve estimation precision.

Results:
Analysis finds that, under favorable wind alignment conditions, traction forces can reach up to 500 kN for the model vessel and kite array. For winter navigation scenarios in the Black Sea, estimated fuel savings can reach 15%, depending on wind direction and availability. Corresponding CO₂ emission reductions scale proportionally with fuel savings.

Conclusions:
The findings indicate that an operational kite-equipped vessel in the Black Sea achieves quantifiable reductions in emissions under seasonal wind conditions. Integrating reanalysis wind data with propulsion balance modeling establishes a transferable framework for evaluating the real-route performance of kite-assisted vessels in regional maritime transport.