SPANISH sail designer Bound4blue said an independent assessment of its suction sails’ performance has verified expected fuel savings, helping its business case.

Three sails on the Louis Dreyfus Armateurs-owned and Airbus-chartered ro-ro Ville de Bordeaux (IMO: 9270842) netted average fuel savings of 1.7 tonnes per day across 12 months.

Bureau Veritas Solutions Marine & Offshore confirmed annual savings of 568 tonnes of fuel and 2,181 tonnes of CO2 emissions, with peak savings of up to 5.4 tonnes per day.

Bound4blue said the savings were consistent with its early projections, with measurements gleaned from fuel consumption and weather data.

It is hoped that wind-assisted propulsion systems will help ships save on fuel and compliance costs, but lack of real-world performance data has slowed their uptake across the industry.

Verified average savings figures may help operators make up their minds on the technology, the benefits of which depend on the specific ship and trade.

“We’re thrilled to see this hard-working vessel making significant daily savings, with really exciting peak numbers that demonstrate huge potential,” Bound4blue chief executive David Ferrer said.

The company said the savings were achieved without relying on weather routing and did not account for regulatory carrots being offered for sail buyers.

Ville de Bordeaux carries Airbus sub-assemblies from Europe to the US.

LDA transport & logistics managing director Mathieu Muzeau said: “It’s hugely rewarding to see the scale of savings enabled through this early adoption, while the performance achieved was also noteworthy — with a boost to vessel speed — as was the complete simplicity of the operation.”

Interest in wind power has increased since the onset of the EU ETS and FuelEU Maritime regulations, as a way to reduce compliance costs.