This study evaluates the technical, economic, and environmental feasibility of deploying a large-scale rooftop solar photovoltaic (PV) system to offset the annual electricity demand of a typical government school in Saudi Arabia. Electricity consumption data measured for a representative school indicated an annual demand of approximately 2.12 GWh, with an applicable government school electricity tariff of 0.32 SAR/kWh. The system was modeled using RETScreen Expert under site-specific climatic conditions to conduct a feasibility analysis for a school located in Dhahran, Saudi Arabia. Three Tier-1 PV module technologies Jinko Solar, and Trina Solar were assessed under fixed-tilt and single-axis tracking configurations. For fixed-tilt systems, a slope sensitivity analysis was conducted, to identify the optimal tilt angle of 22°, which was adopted across all simulations to maximize an annual energy yield. The results showed that a 1.35 MW PV system could fully offset the school’s annual electricity demand. Although all configurations achieved similar annual energy generation, the Jinko Solar modules exhibited the shortest simple payback period of 4.9 years, driven by higher module efficiency. Single-axis tracking improved spatial utilization and financial performance. The proposed PV system achieved annual CO2 emission reduction of approximately 1,379 t CO2. Overall, the findings confirm that high-efficiency rooftop PV systems, particularly those based on Jinko Solar modules, are technically feasible, economically attractive, and environmentally beneficial for public educational institutions in Saudi Arabia owing to their relatively high tariff rates.