Evaluation of the environmental and economic impacts of electric propulsion systems onboard ships: case study passenger vessel

The International Maritime Organization (IMO) announced that maritime transport share by 2.89% in global greenhouse gases. Electric propulsion system appears as a promising option for reducing ship emissions, especially for high-powered vessels. The aim of the current paper is to investigate the environmental and economic impact of using electric propulsion systems. Simple eco-environmental model was presented to assess the best propulsion system for passenger ships. A comparison between diesel electric (DE) and combined gas turbine electric and steam (COGES) propulsion systems is conducted. As a case study, one of the cruise ships is selected. The results showed specific environmental benefits of COGES over DE propulsion option. From the design and operational viewpoints, COGES propulsion system is more energy efficient than DE by 9.3% and 27.55%, respectively. Economically, the values of the life cycle costs are 5,013 and 6,042 $/kW for DE and COGES systems, respectively. Finally, COGES seems as a greener option with a life-cycle cost-effectiveness of 612, 1970, and 6 $/ton for NOx, SOx, and CO2 emissions, respectively.