EPS Tanker Studied to Determine Results of Wind-Assisted Propulsion

A new study seeks to quantify the beneficial impact of adding wind-assisted propulsion to vessels while also establishing a framework for assessing the technology’s benefits in reducing fuel consumption and emissions. The study, which took place on the Eastern Pacific Shipping product tanker Pacific Sentinel (50,322 dwt), was conducted in association with the Global Center for Maritime Decarbonisation in Singapore.

The authors of the study highlight that one of the key barriers to the adoption of wind-assisted propulsion lies in the inherently variable fuel savings from wind-assisted propulsion systems. They note it depends on operational and environmental factors, such as routing and weather conditions. While there are approximately 70 commercial vessels worldwide currently equipped with some form of wind assistance technology, they note there is no standardized methodology for measuring and validating the performance. The new study was one of several that looks to address these issues.

The chemical tanker was fitted with three 22-meter (72-foot) suction sails in March 2025. The fully autonomous wind-assisted propulsion system (WAPS) manufacturer, bound4blue, said it would help the vessel reduce overall energy consumption with forecasted energy consumption savings of around 10 percent, depending on vessel routing.

GCMD’s study set out to measure the performance of the system under real-world operating conditions. They studied the vessel be May and September 2025 as it was sailing mostly between the U.S. East Coast and the West Coast of South America. The methodology included high-frequency data collection at 15-second intervals with sensors as well as on-off testing of the system. Statistical analysis was applied to all the data. On-off testing, they said, with the data systems, made it possible to isolate the propulsion contribution of the suction sale and measure with confidence.

“Accordingly, the mean instantaneous power savings derived from valid on-off tests during this period was 7.2 percent, with a 95 percent confidence interval between 6.2 and 8.2 percent. If the vessel experienced more favorable wind conditions, the savings could be higher,” concludes the report.

Several factors impacted the testing, the most prominent being the fact that the vessel was sailing almost entirely with a headwind. There were instances where, with a near-headwind, the system resulted in a negative power savings as low as negative 14 percent, but the system can be switched off in adverse conditions.

The most favorable operating conditions for the suction sails occurred when the wind came from the beam. Even still, the study found instantaneous savings reached as high as 28.1 percent when the apparent wind angle was 47 degrees, and wind speed was 15.3 m/s.

The report says that by isolating the effects of environmental and operational variability, the method underpins a robust framework for validating WAPS performance under operating conditions. By applying the method across multiple vessels and operational profiles, GCMD and its partners aim to build a comprehensive evidence base that captures the full performance envelope of WAPS. They believe the validated datasets form the foundation for predictive performance models and provide the transparency needed to support performance-linked financing mechanisms for the adoption of WAPS.