Quantifying Solar Irradiation and Photovoltaic Energy Yield at Optimal Tilt Angles: A Case Study of Gojra, Punjab, Pakistan

A high‑resolution, satellite‑derived solar resource assessment was conducted for Gojra, Punjab, Pakistan (31.15° N, 72.69° E) using the 2025 Global Solar Atlas (GSA, Solargis/World Bank) site report and map layers. Long‑term climatological irradiance indicators-global horizontal irradiation (GHI), direct normal irradiation (DNI), diffuse horizontal irradiation (DIF), and global tilted irradiation (GTI)-were extracted and analysed at annual, monthly, and hourly time scales. The fixed‑tilt design orientation was selected using the atlas‑provided optimum tilt and azimuth (OPTA), and the corresponding PV electricity output (PVOUT) was used to estimate the energy yield of a representative 1 MWp grid‑connected PV plant under realistic loss assumptions. Gojra exhibits a strong solar resource, with annual averages of GHI ≈ 1794 kWh m⁻², DNI ≈ 1307 kWh m⁻², and GTI at OPTA ≈ 1975 kWh m⁻², yielding an expected annual generation of ≈ 1.545 GWh (specific yield ≈ 1545 kWh kWp⁻¹; capacity factor ≈ 17.6%). Seasonal and diurnal profiles indicate peak generation during late spring and early summer, with thermal conditions remaining within typical operating envelopes. The resulting data‑driven workflow supports evidence‑based solar siting and preliminary plant design for central Pakistan.