Anemoi Marine Technologies Ltd (Anemoi) and Lloyd’s Register (LR) have published a new paper encouraging closer alignment between existing methodologies used to verify the performance of wind-assisted propulsion systems (WAPS). The research highlights how complementary frameworks can be brought together to strengthen consistency, transparency and industry confidence.

The paper builds on LR’s earlier verification of Anemoi’s new in-service performance and forecasting model calibration methodology, designed specifically for WAPS. The new research assesses how that method fits alongside two existing frameworks: the International Towing Tank Conference’s (ITTC) guidelines for sea trials and supporting performance prediction and DNV’s recommended practice for in-service testing.

Currently WAPS users and providers are applying a range of different approaches to performance analysis, making it difficult to compare results like-for-like and build a robust business case for decision makers to commit to WAPS installation on their vessels.

The analysis shows that the three methodologies are complementary. While ITTC guidelines provide a short-term verification of predictions under controlled conditions and DNV’s recommended practice offers long-term in-service assessment, Anemoi’s verification method provides the bridge between in-service measurements and actionable fuel-saving predictions.

The findings suggest that by selectively combining these strengths, an integrated and standardised approach would give ship operators’ an invaluable tool for maximising the cost-saving potential of WAPS installations. This work would simplify comparison between solutions and strengthen confidence in reported savings at a time when more and more vessel operators are considering wind propulsion technologies.

Anemoi’s process, verified by LR in 2025, involves measuring vessel data when the wind-assisted propulsion system is turned on and off while encountering various conditions during regular operation. The data is then used to calibrate predictions on forces generated by the rotor sail system and their impact on the vessel, which can be used to predict voyage fuel savings with high levels of confidence. The process is technology agnostic and can be applied on all vessel types.

The new paper was presented at the Royal Institute of Naval Architects’ RINA Wind Propulsion 2026 conference on February 17.

“Accurate measurement and prediction of the real savings made by vessels using WAPS is essential for giving confidence to ship owners and operators who want to harness wind energy in order to reduce environmental impact and fuel costs. With our verification process and our new efforts pointing to the potential convergence of methodologies, Anemoi is helping to guide the standardisation efforts that are needed to ensure this market flourishes.”

Luke McEwen
Technical Director, Anemoi Marine Technologies Ltd

“Verification of performance assessment methodologies is a core part of LR’s mission to assure both safety and efficiency standards for maritime stakeholders—and particularly important in emerging sectors where processes have yet to be fully standardised. We are therefore delighted to partner with Anemoi once more to advance understanding of performance verification as the WAPS market matures.”

Dr Santiago Suarez de la Fuente
Ship Performance Manager, Lloyd’s Register Advisory