Digging into the weeds of the EEDI is a whole ‘nother kettle of fish, so let’s just take Lloyd’s word on that double-digit improvement. As cited by Anomie, Lloyd’s has “validated that the newbuild Newcastlemax would have its EEDI score reduced from 1.92 to 1.37 (29% reduction) by installing six 5x30m Rail Rotor Sails and 1.47 (23% reduction) by installing four 5x35m Folding Rotor Sails.”
As for how it works, that’s easy. “The Rotor Sails are driven to rotate by a motor,” Anemoi explains. “When a wind flow meets the spinning Rotor Sails, a pressure differential is created. This causes a thrust force which provides auxiliary propulsion to the vessel and can be used to increase the vessel speed or reduce the consumption of the main power unit.”
See https://cleantechnica.com/2022/07/08/lloyds-register-gets-behind-wind-power-for-cargo-ships/
#environment #ships #wind #windpower