**2. Case study**

As shown in **Figure 1**, a 2.4 m height structure with a PV panel installed on its slanted roof has been studied numerically in this research. To evaluate the effects of wind direction, seven angles between the wind direction and the structure (0, 30, 60, 90, 120, 150, and 180 degrees) and two free stream velocities of 2 and 5 m/s have been considered, the main directions are shown in **Figure 1**. The distance between the panel and the roof surface is 0.1 m. The inclination angle of the roof or module is 30 degrees. The dimensions of the module were 1 m by 1.3 m, oriented such that 10 cm of the

**Figure 1.** *Schematic view of the rooftop-mounted PV and air domain with wind directions.*

*Influence of Wind Incidence Angle on the Cooling of Rooftop-Mounted Solar Panels DOI: http://dx.doi.org/10.5772/intechopen.109610*


**Table 1.** *Characteristics of the PV panel.*

roof-top on all sides remained unobscured by the module when viewed from above. Adequate distance between the structure and the domain boundaries has been considered to correctly model the wind effects.

The following equation has been used for the wind velocity profile [7]:

$$U(h) = \left(\frac{h}{h\_o}\right)^{\beta} U\_{\text{ref}} \tag{1}$$

where β is a constant equal to 0.17, *ho* is the total inlet height of 10 m, and *Uref* is the average freestream velocity (2 or 5 m/s).

Further, the applied solar heat flux on the PV cells is 600 W/m2 . It is worth mentioning that of the total solar radiation incident upon a PV panel, a portion is reflected or converted into electricity (about 20%). The rest is converted into heat which in turn increases the PV temperature. Here, the applied heat flux of 600 W/m<sup>2</sup> is the amount of radiation that is converted into heat and modelled as heat generation in the simulation. The PV panel consists of five layers including glass, EVA, PV cells, EVA, and Tedlar, respectively, glass being the layer adjacent to the external domain and Tedlar adjacent to the air gap between the panel and roof. The characteristics of the PV panel are shown in **Table 1** [8].
