## 5 Discussion and Analysis
It can also be noted from samples of the results presented in Figures 3-10 as well as previous predictions that such an improvement in the heat transfer capacity becomes more significant with the increase in the volume concentration of the particle loading in nanofluids. This enhancement in the heat transfer capacity of the heat transfer fluid increases the thermal energy delivered to the waste heat boiler of the ORC and thus, increases the power output of the ORC and the ORC efficiency. Therefore, the results presented in the aforementioned figures and others obtained in this study show that the enhancement of the efficiency of the hybrid system in question is significantly dependent upon not only the solar radiation but also on the nanofluids concentration and the type of nanofluid as well as the fluid flow temperature driving the ORC. In addition, elsewhere in the paper, a comparison between the different nanofluids is presented to show the enhancement of the hybrid system efficiency using nanofluids over the water as heat transfer fluid. Figure 5: Hybrid system efficiency for Nanofluid CuO at different temperatures and 20% volumetric concentration. Figure 6: Hybrid system efficiency for Nanofluid Al\({}_{2}\)O\({}_{3}\) at different temperatures and 20% volumetric concentration. Figure 8: Hybrid system efficiency for Nanofluid Fe\({}_{3}\)O\({}_{4}\) different temperatures and 10% volumetric concentration. Figure 7: Hybrid system efficiency for Nanofluid SiO\({}_{2}\) at different temperatures and 10% volumetric concentration. Moreover, the results presented in the aforementioned figures as well as others obtained also demonstrate that a higher hybrid system efficiency has been oberserved with nanofluid CuO than the other nanofluids under investigation and water as the heat transfer fluid. This has been reported in previous studies, namely [PERSON] [18], [PERSON] et al. [19] and [PERSON] et al. [20]. The transport properties, such as density, specific heat, heat capacity, viscosity, and thermal conductivity of nanofluids are the main properties that impact the convective heat transfer of nanofluids [18]. It should be noted that these transport properties have unique the function of temperature of the base heat transfer fluid integrated nanofluid. Therefore, as reported in other references, namely [18, 19, 20, 21, 22, 23], nanofluid CuO thermo-physical properties are the main driver for the higher hybrid system efficiency when CuO is used as the heat transfer fluid. Figure 10: Hybrid system efficiency for Nanofluid Al\({}_{2}\)O\({}_{3}\) different temperatures and 10% volumetric concentration. Figure 9: Hybrid system efficiency for Nanofluid CuO different temperatures and 10% volumetric concentration. The new concept of the ORC cycle presented hereby includes an added feature which is the integration of a cooling capability to the ORC cycle for the cooling or freezing effect, depending upon the boiling temperature of the refrigerant mixture circulating in the ORC cycle. Figures 11-15 show the different parameters that impact the cooling capabilities of this cycle. The results depicted in these figures demonstrate that the cooling effect produced depends upon various parameters, such as the solar radiation, the temperature of the heat transfer fluid and the types of nanofluids and their concentrations. It is quite evident from the results presented in these figures and others obtained during this study with the different nanofluid concentrations that the higher the heat transfer fluid temperature, the higher the cooling effect produced. As discussed elsewhere in this paper in the case of the hybrid system efficiency, it is believed that the enhancement of the cooling effect is due to the higher thermo-physical properties of the nanofluids. In particular, it can be observed from Figure 16 that the nanofluid CuO has the highest cooling effect produced compared to the other nanofluids under investigation including water as heat transfer fluid.