Industrial processes release a considerable amount of thermal energy through exhaust gases and flue gas systems, and a significant portion of this energy is discharged into the surroundings without further utilization. Thermoelectric generators (TEGs) provide a direct method for converting a temperature difference into electrical energy through the Seebeck effect. This paper presents the design and fabrication of a thermoelectric waste heat recovery module intended for installation on a vertical industrial flue gas duct. The system consists of a mild-steel vertical duct, copper thermal collector plates, TEG modules, aluminium heat sinks with cooling fans, thermal insulation, and an electronic monitoring system built around an Arduino UNO, K-type thermocouples with MAX6675 modules, voltage and current sensing circuits, a DC-DC converter and an LCD display. The primary objective is not high-power generation but the recovery of otherwise wasted thermal energy and its conversion into useful electrical energy. In a prototype test at a pipe temperature of 140.8 °C, a temperature difference of 38.5 °C across the TEG modules gave an output voltage of 10.96 V and an output power of about 9 W. The developed prototype provides a platform for studying thermoelectric energy harvesting from industrial exhaust systems and for evaluating the influence of thermal gradients, heat transfer, cooling conditions and electrical loading on TEG performance.

Keywords—Thermoelectric Generator, Waste Heat Recovery, Seebeck Effect, Flue Gas, Sustainable Energy, Energy Harvesting, TEG, Industrial Waste Heat.