Solar Potential in Saudi Arabia for Southward-Inclined Flat-Plate Surfaces

Abstract

The major objective of the present work is to investigate into the appropriate tilt angles of south-oriented solar panels in Saudi Arabia for maximum performance. This is done with the estimation of the annual energy sums received on surfaces with tilt angles in the range 15°–55° inclined to south at 82 locations covering all Saudi Arabia. The analysis shows that tilt angles of 20°, 25° and 30° towards south are the optimum ones depending on site. These optimum tilt angles define three distinct solar energy zones in Saudi Arabia. The variation of the energy sums in each energy zone on annual, seasonal and monthly basis is given; the analysis provides regression equations for the energy sums as function of time in each case. Furthermore, the spatial distribution of the annual global inclined solar energy in Saudi Arabia is shown in a solar map specially derived. The annual energy sums are found to vary between 1612 kWhm−2year−1 and 2977 kWhm−2year−1 across the country. Finally, the notion of a correction factor is introduced, defined, and employed. This factor can be used to correct energy values estimated by a reference ground albedo to those based on near-real ground albedo.

Solar Potential in Saudi Arabia for Inclined Flat-Plate Surfaces of Constant Tilt Tracking the Sun

“…Hourly values of H b and H d were downloaded from PV-GIS for all 82 sites; Table 1 shows the names and provides the geographical coordinates of these sites, while Figure 1 is a map of Saudi Arabia showing their location. The criterion for selecting these sites is mentioned in [1].…”

“…The first category of solar systems is also called stationary or static, while the other two are dynamic, because of their Sun-tracking ability. Farahat et al [1] examined the mode (i) for the performance of flat-plate solar collectors in Saudi Arabia. This work is a continuation as it investigates the mode (ii) for the solar energy received on single-axis systems across the country.…”

“…The calculation of the optimum tilt angle and orientation for receiving maximum solar energy on solar flat-plate collectors has been the objective of various studies that use different strategies for obtaining solar radiation data: solar radiation modelling, e.g., [4,5]; combining with ground-based solar data, e.g., [6]; or utilising international data bases, e.g., [7,8]. Recently, a new method was presented by [9] for Greece and was applied in a recent study for Saudi Arabia [1]. The proposed method finds the maximum solar energy received by flat-plate collectors with southward (northward) orientation in the northern (southern) hemisphere.…”

“…An extensive review of the studies conducted for Saudi Arabia related to the present work can be found in [1].…”

“…(i) For the first time, solar maps for Saudi Arabia showing maximum energy on optimally inclined flat surfaces tracking the Sun are derived. (ii) For the second time the three solar energy zones introduced by the same authors for Saudi Arabia [1] are also utilised here. (iii) The notion of the (ground-albedo) correction factor introduced in [1] is also used here, and the shape of the universal curves (representable as nomograms) of this parameter in relation to the tilt angle and the ground-albedo ratio is confirmed.…”