Enhancing Maritime Energy Efficiency: Route Optimization for Rotor-Sail-Assisted Bulk Carriers

The International Maritime Organization (IMO) has spearheaded decarbonization efforts in international navigation, setting ambitious goals, including achieving net-zero greenhouse gas (GHG) emissions by 2050. Despite extensive research on hybrid systems, such as wind-assisted diesel-propelled vessels, there remains a gap in comprehensive tools for comparing fuel consumption between diesel-propelled ships and those assisted by rotor sails in route optimization. 
This study aims to estimate the fuel consumption reduction of a bulk carrier equipped with rotor sails and without them, by applying Dijkstra´s algorithm for optimization of fuel consumption, voyage time and distance in Python – Gurobi. As a case of study was employed a voyage from Tubarão port (Brazil) to Zhanjiang port (China) using climatology data from July, considering five rotor sails on deck and varying the aspect ratio and the disk/diameter rotor ratio.
The most relevant results indicated a fuel consumption reduction when the aspect ratio is 4 of 24,43% when using rotor sails but it increased the voyage time in 9,6%, but for an aspect ratio of 8 the fuel consumption is reduced to 16,15% and increasing only in 3% the voyage time. Therefore, combining route optimization with wind assisted propulsion of rotor sails could generate positive impacts in fuel consumption without affecting voyage time.