Thermoelectric Generators for Battery Regeneration: Waste Heat Utilization & Back Pressure Reduction

Abstract

Waste heat recovery has become a critical research area in the quest for improving automotive energy efficiency. Internal combustion engines lose a large amount of their energy as heat through exhaust gases. Thermoelectric generation technology presents a promising approach to capturing and converting this waste heat into useful electrical energy. In this work, a theoretical study on the application of thermoelectric generators (TEGs) for battery regeneration by converting waste heat specifically from internal combustion engine exhaust into usable electrical energy is proposed. A prototype system incorporating TEG modules was also designed focusing on the elimination of back pressure i.e. free flow of exhaust gas is ensured. Simulations (thermal analysis) done using Ansys Workbench. Two heat exchanger materials, aluminum and copper alloys were evaluated for their heat transfer efficiency. The results indicate that copper achieves superior heat transfer, capturing approximately 84% of exhaust heat compared to 77% for aluminum. However, aluminum remains a viable alternative due to its light weight and cost-effectiveness. Experimental findings show that an optimized series-parallel configuration of 24 TEG modules can effectively generate the necessary voltage (13–15V) and current (3.5–7A) to charge a 12V automotive battery. This research underscores the potential of TEG-based battery regeneration systems in enhancing energy efficiency, reducing dependence on grid electricity and promoting greener automotive technologies. Future work could focus on scaling this solution for hybrid and electric vehicles, optimizing thermoelectric materials, and integrating advanced cooling mechanisms to improve overall efficiency.

Keywords: Thermoelectric Generators, TEG, Waste heat utilization, battery charging, Exhaust gas heat utilization