Numerical Analysis of Wingsails as Propulsion Power Assistance to the Contribution of Energy Efficiency and Decarbonization: Case of a 6500-Ton DWT Tanker Ship with Different Sail Arrangements

The Paris Agreement, led by the UNFCCC, targets limiting global temperature rise to 1.5°C above pre-industrial levels. In response, the International Maritime Organization (IMO) aims for zero emissions from maritime transport by the early 2100s. IMO introduced the Energy Efficiency Design Index (EEDI) for new ships in 2013 and the Energy Efficiency Existing Ship Index (EEXI) in 2023, alongside the Carbon Intensity Indicator (CII) to monitor emissions. Installing wind-powered propulsion is one method suggested for compliance. This study focuses on achieving EEXI and CII compliance using wind assistance, examining wingsail retrofitting on a 6,500-tonne DWT tanker in Indonesia. Computational Fluid Dynamics (CFD) models are employed to predict thrust and drag based on wind conditions. Annual energy savings for different sail configurations are evaluated using published wind data, allowing for a comparison of savings versus capital costs to assist ship owners in decision-making.