Solar Potential in Saudi Arabia: Spatio-temporal and Plates-inclination Effects on the Performance of Photovoltaic Solar Panels

Inclined and flat-plate photovoltaic (PV) solar panels have been widely used in many countries and regions for generating electric power. For exploiting the available solar energy in a region, prior knowledge of this potential is necessary. This work investigates the performance of solar panels in 82 locations in Saudi Arabia by calculating the annual energy received on inclined-plate with tilt angles from 15° – 55° inclined to south and flat-plate that continuously follow the daily motion of the sun.  Calculations are performed using a fixed surface albedo of 0.2 and with a near-real value. The analysis indicates that tilt angles of 20°, 25°, and 30° towards the south are the optimum ones depending on the site. These optimum tilt angles define three distinct solar energy zones in Saudi Arabia. The variation of the total energy in each energy zone on a monthly, seasonal, and annual basis is given. Regression analysis for the total energy as a function of time is derived for each zone. Moreover, the spatial distribution of the annual global inclined solar energy in Saudi Arabia is illustrated in a solar map where the total energy is found to vary from 1612 - 2977 kWhm⁻²year⁻¹ for the southward-inclined plates and 2159 – 4078 kWhm⁻²year⁻¹ for the flat-plates across Saudi Arabia. The correction factor, introduced in a recent publication, is used; it is found that the linear relationship between the correction factor and the ground-albedo ratio is general enough to be graphically representable as a nomogram.