Analysis of Waste Heat Utilization from a Briquette Stove for Electricity Generation Using a Thermoelectric Generator

Briquette stoves lose much of their combustion heat through the stove wall, although this waste heat can be converted into small-scale electricity using a thermoelectric generator (TEG). This study aimed to analyze the utilization of briquette stove waste heat for electricity generation using TEGs and to evaluate the effect of combustion air velocity on temperature and electrical output. A quantitative experiment used six SP1848-27145 SA TEG modules connected in series and mounted on the outer wall of a carbon steel stove through steel plates, with heatsinks and cooling fans on the cold side. In each test, 1 kg of coconut-shell charcoal briquettes was burned at air velocities of 1, 3, and 5 m/s. Temperatures, voltage, and current were recorded every 5 minutes for 60 minutes, and the power and conversion efficiency were calculated using Fourier’s law. The average temperature difference across the modules was 44.63, 56.04, and 34.61 °C, producing average electrical power of 0.598, 0.823, and 0.474 W at 1, 3, and 5 m/s, respectively, peaking at 1.37 W at 3 m/s. Conversion efficiencies were 0.79%, 0.87%, and 0.81%. The temperature difference correlated positively with voltage and power. An air velocity of 3 m/s gave the best performance among the tested values, whereas 5 m/s reduced the output, attributed to excess air cooling the flame and shortening burning duration. Although the power and efficiency remain low, the system shows that briquette stove waste heat can be harvested as a source of electricity.