Design and experiment of thermoelectric asphalt pavements with power-generation and temperature-reduction functions

Asphalt pavements tend to absorb solar energy and accumulate heat, which results in several negative effects. They contribute to the urban heat-island effect, plastic deformation of pavements, and aging of asphalt materials. One solution is to convert or transfer the pavement heat. A brand new road thermoelectric generator system (RTEGS) is designed for this purpose. The system added three modules to the traditional asphalt pavement structure: heat-conduction, thermoelectric-conversion, and cold-end cooling. The modules convert heat absorbed in asphalt pavements to electrical energy and reduce the pavement surface temperature. Field testing of the new system subject to a full seasonal change (half a year) was conducted. The data of temperature reduction and voltage output in a field environment were obtained. The results showed that the system reduced the pavement surface temperature by 8–9°C in hot seasons, and the electrical output from an asphalt pavement of size 300 mm × 300 mm × 100 mm reached 0.564 V. At this output, a 10,000 m2 (1 km long and 10 m wide) pavement area would generate about 33 kWh of electrical energy in a single day in the summer, not considering the scale effects of the RTEGS. The system provides a new approach to alleviate the urban heat-island effect, and to convert and utilize solar heat absorbed in asphalt pavement.