Experimental and Field Study of a Pavement Thermoelectric Energy Harvesting System Based on the Seebeck Effect

Methods for harnessing clean energy have received considerable attention recently. In this study, a thermoelectric power generation device is developed for use in road engineering. The thermoelectric generator unit (TEGU) is systematically studied under the influence of various factors including varied temperature differences, load resistance, burial depth, and pavement defects. The experimental results indicate that the output voltage of the TEGU is consistent with the Seebeck effect. When the temperature difference is 60°C, the output power is 24.85 times the power generated when the temperature difference is 10°C. In addition, the deeper the burial depth of the TEGU, the lower the output voltage, and the higher the temperature difference at the same burial depth, the higher the output voltage. In the field test, the TEGU was buried 2 cm below the ground surface. When the maximum temperature difference reached 25.5°C, the open-circuit voltage was 21.41 V and the short-circuit current was 97.2 mA. When the optimal impedance matching resistance was 50 Ω, the output power reached a peak of 0.623 W, and the output voltage was 5.582 V. Furthermore, no significant changes in the power generation ability of the TEGU were observed with different degrees of asphalt pavement defects. The output voltage under typical road conditions when the temperature difference in the laboratory was 30°C only reached 55.49% of that when the temperature difference in the field test was 25.5°C. The developed system enables the conversion of the road surface heat energy and reduction of the internal temperature of the road surface, which can facilitate the development and application of thermoelectric technology.