Experimental, thermodynamic, and economic analysis of a novel small-scale thermoelectric power generation system

Thermoelectric generators coupled with solar ponds offer a promising pathway for converting stored solar thermal energy into electricity. However, conventional thermosyphon-assisted thermoelectric power generation systems are often limited by significant thermal resistance during heat transfer and a low heat source temperature, which reduces the effective hot-side temperature of thermoelectric generators, consequently lowering the temperature gradient and electrical output. To address this limitation, the present study proposes a thermoelectric array-based power generation system designed to minimize thermal resistance and enhance heat transfer from the heat source to hot-side of the thermoelectric. The proposed system is experimentally integrated with a solar pond operating under real ambient conditions, and its performance is further evaluated under controlled temperatures simulating low-grade industrial waste heat sources for clean energy and decarbonization, followed by thermodynamic performance. Finally, the feasibility of the system via economic and environmental assessment is investigated. The results demonstrated that a maximum output power of 7.238 W was achieved with an open-circuit voltage and a short-circuit current of 93.67 V and 0.305 A, respectively, at a source temperature of 80 °C. The conversion and exergy efficiency of the TEG are found to be 4.78% and 34.42%, respectively. The thermal resistance barrier is reduced to 0.012 °C/W, leading to a performance improvement of 1.7–3 times higher than that of previously reported thermosyphon-based systems. The system has achieved an electricity generation cost of 8.96 INR/kWh and reduced CO2 emissions by 85.14 kg/year, demonstrating its potential for sustainable low-grade thermal energy recovery and industrial decarbonization.