© 2023 the Author(s).The waste heat recovery from marine diesel engines is important in terms of improving the energy efficiency of ships. Thermo-electric generator can be used to convert the waste heat in the ship to the electrical energy. This study investigates the effects of different thermo-electric materials and sea water temperatures on the thermal performance of the thermo-electric power generation system. The polyacetylene, Ba8Ga16Ge30, SiGe and (CuI)001Bi2Te3 are considered thermo-electric materials. The energy of the exhaust gases from the marine diesel engine on a handymax-size tanker is used as the waste heat source. The maximum electrical power of 117 kW is produced for (CuI)0.01Bi2Te3 at the sea water temperature of 5°C and the engine load of 100% MCR (Maximum Continuous Rating). However, the minimum electrical power of 18.74 kW is produced for the polyacetylene at 30°C and 75% MCR.