This research investigates the techno-economic feasibility of rooftop solar photovoltaic (PV) systems for the production of energy and the desalination of brackish water in Sawakin, Sudan. To achieve this aim, RETScreen software was utilized. The results demonstrate that tilted surfaces, with an optimal tilt angle of 18°, capture more solar energy than horizontal surfaces, especially in the winter. Additionally, the 7 kW PV system generates 8412.58 kWh of energy annually, while the 8 kW system produces 9614.38 kWh. Both systems have a capacity factor of 13.72%. The findings indicate that both systems are financially viable; however, the 7 kW system has a higher net present value ($4763.60) and a shorter payback period (7.73 years) than the 8 kW system, which has an NPV of $3212.27 and a payback period of 10.90 years. Furthermore, these systems contribute to the decrease of greenhouse gas emissions. The study indicates that rooftop solar PV systems are a practical and sustainable solution for assisting with electricity and water shortages, with the possibility of further optimization based on local grid conditions.