Lloyd’s Register (LR) has validated a new methodology developed by bound4blue to calculate the propulsive power from wind-assisted propulsion systems (WAPS).
The approach, known as the “wind propulsion system force matrix calculation methodology,” provides shipowners with a compliant way to determine the Pwind value of installations.
Pwind represents the propulsive power generated by WAPS and can be deducted from engine power in Energy Efficiency Existing Ship Index (EEXI) and Energy Efficiency Design Index (EEDI) calculations, in line with International Maritime Organization (IMO) regulation /Circ.896. It also contributes to the Wind Reward Factor in FuelEU Maritime, which can ease greenhouse gas targets and reduce costs.
The methodology relies on installation-specific force matrices that reflect thrust under various wind conditions, accounting for sail-to-sail and ship-to-sail interactions. LR confirmed that bound4blue’s approach, combining computational fluid dynamics (CFD) modelling and wind tunnel test results, meets IMO standards.
According to LR, shipowners can now calculate Pwind without full-scale testing, lowering costs and accelerating project schedules. The method is approved for future eSAIL® projects and has already been applied to the juice carrier M.V. Atlantic Orchard, equipped with four bound4blue eSAILs®, chartered by Louis Dreyfus Company (LDC) and owned by Wisby Tankers.
Alberto Llopis, Head of Aerodynamics at bound4blue, said the validation allows clients “to confidently calculate Pwind to simplify regulatory compliance and unlock substantial financial savings.”
Dr Santiago Suarez de la Fuente, LR Advisory Ship Performance Manager, stated that validation supports the safe adoption of new technologies and acknowledged the collaboration of bound4blue and LDC in the project.
Lloyd’s Register (LR) is an international provider of professional services for engineering and technology, operating through Lloyd’s Register Group Limited, a company registered in England and Wales. It offers classification, compliance, and consultancy services primarily to the maritime sector.
bound4blue is a private technology company incorporated in Spain that designs and develops wind-assisted propulsion systems for commercial shipping.
Louis Dreyfus Company (LDC) is a privately held global merchant and processor of agricultural goods, headquartered in the Netherlands.
