Techno-econo-environmental feasibility of retrofitting urban transportation system with optimal solar panels for climate change mitigation – A case study

Two novel solar buses are proposed to mitigate climate change in urban settings. Operational problems of solar power harnessing in cities such as high land costs and dust accumulation on the panels are obviated by installing solar panels on the otherwise rooftop area of the urban buses. Furthermore, the fuel consumption and hazardous emissions of buses decrease by improving their aerodynamic performance. An integrated solar power and aerodynamic model is developed, validated, and employed in a multi-objective optimization algorithm to compare proposed single-part (SiPS) and separate-part (SePS) systems. A multi-level stochastic procedure is applied to obtain a robust plan, calculate the economic payback, and study the feasibility of the optimal system's application using a novel combined economic-environmental ratio in Tabriz metropolitan city. The results showed that the costs of energy and vehicle-specific power were 0.922 $/kWh and 0.864 $/kWh, and −12.71 kW/t and −17.53 kW/t for the optimal SiPS and SePS, respectively. Moreover, 233.76 MWh/year green energy could be generated, 1132 tCO₂-eq/year hazardous emissions could be reduced, and 398,400 US$ land costs could be saved by retrofitting the bus rapid transport routes in Tabriz with the SePS. Although the project was recommended if the energy unit price was greater than 0.25 $/kWh in the case study, it was profitable under almost all probable conditions considering the combined economic-environmental revenue.