## 1 Introduction
They investigated the effect of using this PCM on the PV efficiency at different panel slope (0\({}^{\circ}\) and 15\({}^{\circ}\)). They observed that the temperature of the panel cooled by the PCM decreased about 15 \({}^{\circ}\)C and its power output increased by 8%. [PERSON] et al. [13] carried out experimental and numerical studies to investigate the cooling effect of using a stable paraffin (ZDJN-28)/Expanded graphite composite on PV performance. The results of [13] indicated that the maximum temperature of a PV-PCM panel decreased by 4.7 \({}^{\circ}\)C, and the suitable density of the PCM to achieve high-temperature management performance was 900 Kg/m\({}^{3}\). [PERSON] et al. [14] studied the effect of PCMs from an economical perspective and conducted numerical studies under two Turkish cities' climate conditions. They reported that using PCM cooling decreased the PV panel temperature by 10.26 \({}^{\circ}\)C, increased the efficiency by 0.48-3.73%, and improved the average annual efficiency by 1.59%. [PERSON] et al. [15] examined experimentally the performance of three 20W PV panels cooled by using three different configurations of PCM containers. They reported a 5.3% enhancement in electrical efficiency when they applied a finned container filled with Palm wax-based PCM. They also noticed that the PCM may not be effective in late afternoon with irradiance lower than 500 W/m\({}^{2}\). [PERSON] et al. [16] studied experimentally the performance of a building-integrated photovoltaic cooled by a Glauber's salt-based PCM with a 32 \({}^{\circ}\)C melting point, which is close to the ambient temperature of the experimental location in India. They reported a 10% increase in electrical efficiency resulting from a reduction in the PV surface temperature of up to 8 \({}^{\circ}\)C, compared to a reference PV. [PERSON] et al. [17] investigated the depth of a PCM's container required for the optimal PCMquantity under different operating conditions. They reported that an increase in the ambient temperature of 8 \({}^{\circ}\)C required an increase in PCM tank depth by 1.7 cm, and a large amount of PCMs with a low-melting temperature, i.e., near ambient temperature. A hybrid PV cooling system was introduced by [PERSON] et al. [18] where a PCM container was integrated into a photovoltaic/thermal (PV/T) system. Compared to the conventional PV/T system, the data of [8] revealed that the PV maximum-temperature drop for the PV/T-PCM system reached 15.8 \({}^{\circ}\)C and the output power increased by 7.4 W. This examination was for a PCM with a transition temperature of 30 \({}^{\circ}\)C, which cannot be used with a higher ambient temperature, such as in Riyadh. [PERSON] et al. [19] proposed a mathematical model for predicting the performance of a PV panel cooled by a PCM with a melting temperature of 25 \({}^{\circ}\)C. They noticed that the passive strategies were insufficiently effective to guarantee adequate cooling. The PCM was only able to ensure adequate cooling for the first few hours, and it was only able to reduce the module's operating temperature, on average, for certain period of the day. As soon as the melting was finished, the PCM ceased to function, which caused the panel temperature to quickly increase to a point where it exceeded that of the uncooled panel. Numerous studies on active cooling techniques have been conducted in this area to enhance PV electrical efficiency by regulating the temperature of PV panels in hot climate regions. [PERSON] [20] used a jet cooling approach under a PV panel and reported maximum temperature drops of 33.1 \({}^{\circ}\)C and 16.5 \({}^{\circ}\)C for June and December, respectively, under the hot weather conditions of Dhahran, Saudi Arabia. Using water directly to cool PV panels requires makeup water, and this will increase in dry weather conditions. Additionally, pumping power is required which should be evaluated to determine the net advantage of such approaches. [PERSON] et al.