Cooling Optimization Strategies for Enhancing Energy Harvesting Efficiency in Pavement-Integrated Thermoelectric Generator Systems

Abstract

High solar absorptivity causes asphalt pavements to reach surface temperatures above 60°C during peak summer, accelerating rutting and intensifying the urban heat island effect. These elevated thermal conditions accelerate binder aging, reduce service life, and compromise ride quality and safety. Pavement-integrated thermoelectric generator systems (PTEGS) have the potential to harvest this excess thermal energy while influencing pavement thermal behavior. However, the performance of such systems is strongly governed by the effectiveness of cold-side thermal regulation. This research systematically evaluates different cooling setup configurations in the laboratory. Results indicated that the water-based cooling configuration was the most effective cooling strategy, maintaining cold-side temperatures below 30°C and achieving a maximum voltage output of 0.39 V at a temperature gradient ( Δ T ) of approximately 55.5°C. Phase change material (PCM)-assisted modules, particularly OM36P, stabilized cold-side temperatures and generated 0.29 V, outperforming conventional heat sinks. The findings establish a clear hierarchy of cooling effectiveness and identify hybrid liquid PCM strategies as practical approaches for developing multifunctional and sustainable pavement systems aligned with the United Nations Sustainable Development Goals (SDGs).