Total Solar Radiation and Ideal Incline Angles of a South-Facing Solar Panel in Qena/Egypt

The total Solar Radiation (SR) and the Ideal Incline Angles (IIA) of a south-facing solar panel have been calculated in Qena (26.20° N; 32.75° E; 97m asl), Egypt to maximize the performance of solar energy transformers and photovoltaic (PV) panels. Calculations of the IIA were performed at daily, monthly, seasonal and annual time scales. The Egyptian Meteorological Authority measured the used global and diffuse SR data for five years (2012–2016) in the campus of South Valley University in Qena. Results indicated that the monthly IIA varied from 0° in June and July to 58.9° in December. The seasonal IIA values are 56.3°, 29.7°, 0.1°, and 22.3° during winter, spring, summer, and autumn, respectively. The annual IIA was 27.1°. Besides, for surfaces adjusted at monthly, seasonal and annual IIA, the percentage gains in annual average total SR were 13.64%, 12.78%, and 6.57%, respectively. The percentage losses resulted in using surfaces adjusted at seasonal and annual IIA were 0.78% and 6.24%, respectively in comparison to that adjusted at monthly IIA