Lloyd’s Register (LR) has validated a new calculation methodology developed by bound4blue, giving shipowners a reliable way to harness the regulatory and financial benefits of wind propulsion.
The validation of bound4blue’s ‘wind propulsion system force matrix calculation methodology’ gives shipowners a robust, credible and compliant means to calculate the Pwind value of installations.
Pwind is the propulsive power from a wind-assisted propulsion system (WAPS), used to reduce a ship’s regulatory burden and support environmental compliance. Under International Maritime Organization’s (IMO) MEPC.1/Circ.896, it can be deducted from engine power in Energy Efficiency Existing Ship Index (EEXI) and Energy Efficiency Design Index (EEDI) calculations, and it contributes to the Wind Reward Factor in FuelEU Maritime, easing greenhouse gas targets and lowering costs.
The force matrix, which represents the thrust characteristics of a WAPS under various wind conditions, must be installation-specific (considering both sail-to-sail and ship-to-sail aerodynamic interactions) and validated by an independent verifier.
LR’s validation confirms that bound4blue’s approach, which combines advanced computational fluid dynamics (CFD) modelling with wind tunnel test results, meets IMO standards.
With this validation, shipowners can now calculate Pwind without the need for full-scale testing, reducing costs and speeding up project timelines. The approved CFD-based method can be used for future eSAIL® projects, so shipowners can quickly obtain verified Pwind values for compliance, supporting wind propulsion adoption.
The first installation to benefit from this validated methodology is the juice carrier M.V. Atlantic Orchard, which operates with four bound4blue eSAILs® and is chartered by Louis Dreyfus Company (LDC) and owned by Wisby Tankers.
Alberto Llopis, Head of Aerodynamics at bound4blue, said: “Validation by Lloyd’s Register is a key enabler for shipowners who want to realise the full value of wind propulsion. By confirming our methodology aligns with all applicable international Rules and Standards, it ensures our clients can confidently calculate Pwind to simplify regulatory compliance and unlock substantial financial savings. It removes uncertainty and enables more informed decision-making, underlining the attractiveness of wind as a prime mover in maritime’s much-needed energy transition.”
LR Advisory Ship Performance Manager, Dr Santiago Suarez de la Fuente said: “As the maritime industry works towards ambitious decarbonisation targets, shipowners and technology developers need confidence that their investments align with both evolving regulatory expectations and their own objectives. At LR, we’re proud to support the safe and effective adoption of breakthrough technologies, such as bound4blue’s eSAILs®, by providing transparent, independent validation shipping companies can rely upon. We’d like to thank both bound4blue and LDC for their excellent collaboration on this project.”
