Available solar resources and photovoltaic system planning strategy for highway

The integration of energy and transportation is a prerequisite for ensuring a rational, practical, and sustainable evolution of energy conservation. This study proposes a planning strategy combining the maximum exploitation of solar resources and road area to utilize solar energy in highways entirely. First, the proposed grading criterion was used to evaluate the solar resource capacity of the road. Then, the photovoltaic-available road area was calculated to analyze the feasibility of photovoltaics. Finally, the comprehensive analysis of solar resources and road facilities results in the road photovoltaic energy system. Accordingly, the planning strategy was validated using three typical scenes. The results indicate that there are abundant solar resources within the road area. It demonstrates that solar resources could accurately characterized and error reduced to 50 kWh/m2 by using a 500 m long road segment. Additionally, the exploitability index was proposed to evaluate the magnitude of road area. Moreover, the concept of “road facilities energy consumption circle” was put forward. For verification, 2 km of road segment of Scene A was selected to design photovoltaic systems, which comprise five energy consumption circles, and the self-sufficient rate of each circle is 100 %. The photovoltaic capacity of the largest circle reaches 1400.5 kWh, which suggests that the design is rationalized. The proposed planning strategy promotes the optimization of the siting and deployment of road photovoltaic systems. This study provides technical support for low-carbon energy supply in highways, contributing to sustainable development and net zero emissions in transportation.