Cargill put 37.5-metre steel sails on a chartered bulk carrier and cut its fuel bill

Shipping runs on oil and answers to new carbon rules, and the fleet turns over far too slowly to wait for green fuels. In August 2023 the Pyxis Ocean, an 80,000-tonne bulk carrier owned by Mitsubishi's MC Shipping and chartered by Cargill, left Shanghai with two 37.5-metre WindWings rigid sails designed by BAR Technologies and built by Yara Marine Technologies, installed at a COSCO shipyard — the first ship ever retrofitted with the wings.

The economics were the argument. BAR estimated each sail saves about 1.5 tonnes of fuel per day on an average route, roughly a fifth of consumption in favourable conditions; Cargill's ocean transport chief Jan Dieleman's pitch was that wind 'makes the new fuels a lot more affordable' because 'wind is there for free.' Cargill, a charterer rather than the ship's owner, ate the prototype risk and accepted a seven-to-ten-year payback, betting the learnings would carry across the ships it charters.

After six months crossing the Indian, Pacific and both Atlantics, the results held up: DNV verified savings of more than 11 tonnes of fuel per day in near-optimal conditions, a 37% emission cut, matching BAR's simulations. Wind-assist works with whatever fuel the ship runs, so it compounds with the energy transition instead of waiting for it.

Retrofit free wind onto the ships already at sea

The existing fleet will outlive any fuel transition, so cutting its fuel use now beats waiting decades for replacement ships.

Wind is free and fuel-agnostic: it lowers cost whether the ship burns oil today or green methanol tomorrow.

A charterer funded the trial because it controls cargo demand and the decarbonization commitment, while the shipowner got a free upgrade to its asset.

Rigid wings are automated — no crew re-rigging canvas — so a 19th-century energy source runs with 21st-century operations.

The retrofit path scales through ports and charts rather than shipyards: Cargill consulted more than 250 ports on handling wind-assisted vessels.

When an industry must retool, look for the upgrade that bolts onto what already exists — and let the buyer who owns the demand, not the asset, fund the experiment.

The DNV-verified six-month trial cleared Cape Horn and the Cape of Good Hope and matched the designer's simulations. BAR Technologies' CEO John Cooper predicted most Kamsarmax bulkers would eventually carry three wings, multiplying savings 1.5-fold, and that half of new-build ships would feature wind propulsion by 2025. Cargill kept pushing to make wind-assisted vessels operable across global trade routes, and by 2026 BAR had teamed with Korean Register, HD Hyundai and the Liberian Registry to study wing sails on a new generation of LNG carriers.