## 1 Introduction
### The Sun Path of Ha'il City  
Sun path diagrams are appropriate for depicting the annual changes happening about the Sun's path. As shown in Figure 2, the midday sun in Ha'il city is at a 39\({}^{\circ}\) inclination during the winter solstice. The inclination is 84\({}^{\circ}\) during the summer solstice. These numbers indicate a 45\({}^{\circ}\) deviation between the solstices as a result of the Earth's declination, varying between \(-23^{\circ}\) and \(+23^{\circ}\) over the year. In contrast, during spring and autumn, the Sun has a similar path and an inclination of 63\({}^{\circ}\), which is present between the two solstices.  
\begin{table}
\begin{tabular}{l c c c c} \hline \hline
**Title of Study and Year** & **Light Shelf** & **Experimental** & **Daylighting** & **Integrated PV** \\  & **Parameters** & **Measurement** & **Simulation** & **with Light Shelf** \\ \hline Dynamic internal light shelf for & Height of ILS, & & & \\ tropical daylighting in high-rise office & number of ILS & yes & yes & no \\ buildings, Malaysia, 2016, [5] & & & & \\ \hline Evaluating daylight performance of & & & & \\ light shelves combined with external & & & & \\ blinds in south-facing classrooms in & & & & \\
**Athens**, 2016, [15] & & & & \\ \hline Investigating the Influence of Light & & & & \\ Shelf Geometry Parameters on & & & & \\ Daylight Performance and Visual & & & & \\ Comfort, a Case Study of Educational & & & & \\ Space in Tehran, Iran, 2016, [19] & & & & \\ \hline Energy-saving performance of light & & & & \\ shelves under the application of & & & & \\ user-awareness technology and & & & & \\ light-dimming control, South Korea, 2018, [20]. & & & & \\ \hline A preliminary study on the & & & & \\ performance of an awning system & Angle, awning & & & \\ with a built-in light shelf, South & system & yes & yes & no \\ Korea, 2018, [16]. & & & & \\ \hline Development and Performance & & & & \\ Evaluation of Light Shelves Using & Width Adjustability & yes & no & no \\ World-Adjustable Reflectors, South Korea, 2018, [21]. & & & & \\ \hline Performance evaluation of a light & & & & \\ shelf with a solar module based on the solar module attachment area, & Angle, PV coverage & yes & yes & yes \\ South Korea, 2019, [13]. & & & & \\ \hline Experimental Analysis of the & & & & \\ Performance of Light Shelves in & & & & \\ Different Geometrical Configurations & Angle, curved LS, & & & \\ Through the Scale Model Approach, & & & & \\ South Korea, 2020, [6]. & & & & \\ \hline Optimization of Daylight & & & & \\ Performance Based on Controllable & Angle, width/depth & & & \\ Light-shelf Parameters using Genetic & ratio, height, and & & & \\ Algorithms in the Tropical Climate of & & & & \\
**Malaysia**, 2020, [22] & & & & \\ \hline Performance Evaluation of External & & & & \\ Light Shelves by Applying a Prism & & & & \\ Sheet, South Korea, 2020, [23]. & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 1: _Cont._The solar energy incident on the southern and northern parts of the building is not the same since the southern side has better incident sunlight compared to the northern side. In contrast, considering the eastern and western directions, the incident solar energy exhibits symmetry. As a result, there should be a difference in the light intensity once the light shelves are attached.