Recent studies have highlighted the factors influencing the thermal performance of Pavement Solar Collectors (PSC), such as thermophysical properties of materials, geometrical specifications, and operational conditions. The present study introduces a new approach to investigating the impact of various parameters on the long-term performance of PSCs.

The Response Surface Methodology (RSM) is used to optimise the experimental design by reducing the number of simulations resulting from the combination of several design parameters and ample design space. Hence, the proposed PSC system design aims to: i) assess the heat extraction capacity; ii) investigate the ability to diminish the asphalt surface temperature (STR); and iii) determine the reduction in asphalt layers’ rutting potential (RTR), through a coupled RSM and Finite Element (FE) simulation framework.

The proposed statistical prediction regression models for heat harvesting capacity, STR, and RTR, adequately represent the experimental data with predicted R2 values above 0.95. The pipe spacing, flow rate, and inlet supply temperature show a high sensitivity to the objective functions, while other parameters display a less sensitive response. Finally, a multi-objective optimisation framework using the NSGA-II is proposed to seek a Pareto front solution in the design space, considering different (or equal) weights for the objective functions.