The necessity of reduction in the emission of polluting gases and to preserve water resources are of the issues that highlight the importance of providing an approach for replacing fossil fuel power plants by renewable power plants. In this study, the capacity of the water and wastewater plants of the MARKAZI Province in constructing solar power plants was examined and analyzed in terms of contributing to the energy crisis of this province. In this regard, first, information on electricity consumption, area, geographical coordinates and characteristics of the area around all construction sites owned by the water and wastewater company was collected; then, by applying some environmental constraints, a total of 62 suitable construction sites with a total nominal power of 80 MW were determined. The power plants corresponding to these construction sites were designed using the PVsyst software, and the total annual production capacity and carbon emission reduction were obtained by this software. Next, three scenarios of the current situation, constructing 50 percent and constructing 100 percent of the existing capacity in the Water and Wastewater Company by the year 2030 were considered. Since the Shazand Thermal Power Plant is the main electricity producer in the province, the results were examined in each scenario from the perspective of environmental indicators such as corresponding fuel consumption and the amount of reduction in carbon dioxide emissions in this power plant. The results indicated the positive effect of implementing the second and third scenarios in reducing the fuel consumption of the Shazand Thermal Power Plant by 31 and 63 percent, respectively, compared to the current situation scenario. In addition, in terms of reduction in carbon emissions, the results indicated the carbon dioxide emissions reduced by 17 and 36 percent, respectively, in the second and third scenarios compared to the current situation.