Simulation and experimental study on the energy performance of a pre-fabricated photovoltaic pavement

Abstract

Photovoltaic pavement (PVP) is an emerging technology to harvest solar energy from roads, which could use the limited urban area renewable energy production, especially under the carbon neutrality targets. This study proposes a thermal-electrical mathematical model for a PVP system based on the Finite Difference method on heat nodes and a 5-parameter PV generation model. An outdoor test is conducted for model validation, showing 1.68% and 3.60% mean absolute percentage errors for PV cell temperature and output. Lab tests and road anti-skid property tests are also conducted. The experiment results show that the module PV output on a sunny day could reach 0.68 kWh/m2, with electrical efficiency of 14.71%. Based on the proposed model, two cases, in Hong Kong and Shanghai, are analyzed for an entire year. The parametric analyses recommend epoxy resin filling instead of air filling, with the annual maximum PVP module surface temperature reduction at 8.6% (Shanghai) and 8.4% (Hong Kong). The influence of road surface materials and asphalt concrete depth variation are also discussed. Besides the obvious heat island effect alleviation in Summer found from the surface temperature decrease, the snow melting potential in Winter could also be found with the increase of minimum surface temperature by 1.02 °C (Shanghai). Moreover, the potential of PVP application is also analyzed for more than 200 Chinese cities, demonstrating the heat and electrical performances with seasonal average results, with maximum seaonsal average road surface temperature reduction at −4.18 °C in summer and maximum increase, e.g., for Beijing up to 3.36 °C in Winter. The cities in the west and northeast China are shown with higher PVP generation potential.