The maritime industry faces many challenges regarding the adverse environmental impact, whether at the level of legislation set by the International Maritime Organization (IMO) or the economic crises that arising from the Covid-19 pandemic. IMO has found that the highest percentage of ship emission is mainly coming from the ship propulsion systems. Therefore, the current research proposes an electric propulsion system to drive the ship instead of the conventional one to reduce ship emissions and enhance energy efficiency. As a case study, a passenger ship is investigated. The results showed that the proposed electric propulsion system has lower emission rates than the conventional one by 10%, 21%, and 88% for CO2, NOx, and SOx emission, respectively. From an energy efficiency point of view, the diesel-electric propulsion system enhances the energy efficiency and complies with the required IMO values as actual energy efficiency is about 66%, 70%, 83%, and 95% of the required IMO values at baseline, phase 1, phase 2 and phase 3, respectively.