## 3 Results and Discussion
### Comparative Analysis
For the present analysis, it can be said that the collecting area of photovoltaic panels, in order to cover the electricity demand of the mechanical subcooling compressor, will have to be about 110 m\({}^{2}\) by  
\begin{table}
\begin{tabular}{l c c c c} \hline \multirow{2}{*}{**Examined Scenarios**} & \multicolumn{2}{c}{**COP**} & \multicolumn{2}{c}{**\(\mathbf{n_{\text{ex}}}\)} \\ \cline{2-5}  & **M-SC** & **ACH-SC** & **M-SC** & **ACH-SC** \\ \hline T\({}_{\text{c}}\) = 35 \({}^{\circ}\)C-T\({}_{\text{e}}\) = \(-\)35 \({}^{\circ}\)C & 60.77\% & \(-\)7.67\% & 60.81\% & 54.87\% \\ T\({}_{\text{c}}\) = 35 \({}^{\circ}\)C-T\({}_{\text{e}}\) = \(-\)25 \({}^{\circ}\)C & 50.24\% & \(-\)22.87\% & 50.24\% & 46.12\% \\ T\({}_{\text{c}}\) = 35 \({}^{\circ}\)C-T\({}_{\text{e}}\) = \(-\)15 \({}^{\circ}\)C & 42.89\% & \(-\)35.46\% & 42.87\% & 38.30\% \\ T\({}_{\text{c}}\) = 35 \({}^{\circ}\)C-T\({}_{\text{e}}\) = \(-\)5 \({}^{\circ}\)C & 37.17\% & \(-\)45.92\% & 37.17\% & 30.60\% \\ T\({}_{\text{c}}\) = 35 \({}^{\circ}\)C-T\({}_{\text{e}}\) = \(-\)5 \({}^{\circ}\)C & 32.38\% & \(-\)56.14\% & 32.40\% & 23.00\% \\ T\({}_{\text{c}}\) = 40 \({}^{\circ}\)C-T\({}_{\text{e}}\) = \(-\)35 \({}^{\circ}\)C & 89.58\% & \(-\)16.65\% & 89.66\% & 82.16\% \\ T\({}_{\text{c}}\) = 40 \({}^{\circ}\)C-T\({}_{\text{e}}\) = \(-\)25 \({}^{\circ}\)C & 69.68\% & \(-\)37.26\% & 69.71\% & 59.23\% \\ T\({}_{\text{c}}\) = 40 \({}^{\circ}\)C-T\({}_{\text{e}}\) = \(-\)15 \({}^{\circ}\)C & 58.29\% & \(-\)30.32\% & 58.34\% & 46.43\% \\ T\({}_{\text{c}}\) = 40 \({}^{\circ}\)C-T\({}_{\text{e}}\) = \(-\)5 \({}^{\circ}\)C & 51.39\% & \(-\)40.87\% & 51.43\% & 37.01\% \\ T\({}_{\text{c}}\) = 40 \({}^{\circ}\)C-T\({}_{\text{e}}\) = 5 \({}^{\circ}\)C & 47.16\% & \(-\)49.09\% & 47.08\% & 29.49\% \\ T\({}_{\text{c}}\) = 45 \({}^{\circ}\)C-T\({}_{\text{e}}\) = \(-\)35 \({}^{\circ}\)C & 124.51\% & \(-\)0.30\% & 124.63\% & 114.97\% \\ T\({}_{\text{c}}\) = 45 \({}^{\circ}\)C-T\({}_{\text{e}}\) = \(-\)25 \({}^{\circ}\)C & 94.29\% & \(-\)27.32\% & 94.36\% & 80.20\% \\ T\({}_{\text{c}}\) = 45 \({}^{\circ}\)C-T\({}_{\text{e}}\) = \(-\)15 \({}^{\circ}\)C & 78.38\% & \(-\)44.21\% & 78.34\% & 58.16\% \\ T\({}_{\text{c}}\) = 45 \({}^{\circ}\)C-T\({}_{\text{e}}\) = \(-\)5 \({}^{\circ}\)C & 69.17\% & \(-\)36.39\% & 69.09\% & 44.25\% \\ T\({}_{\text{c}}\) = 45 \({}^{\circ}\)C-T\({}_{\text{e}}\) = \(5 {}^{\circ}\)C & 63.66\% & \(-\)45.73\% & 63.67\% & 35.53\% \\ T\({}_{\text{c}}\) = 50 \({}^{\circ}\)C-T\({}_{\text{e}}\) = \(-\)35 \({}^{\circ}\)C & 164.90\% & 18.76\% & 164.88\% & 153.33\% \\ T\({}_{\text{c}}\) = 50 \({}^{\circ}\)C-T\({}_{\text{e}}\) = \(-\)25 \({}^{\circ}\)C & 120.42\% & \(-\)15.87\% & 120.48\% & 103.21\% \\ T\({}_{\text{c}}\) = 50 \({}^{\circ}\)C-T\({}_{\text{e}}\) = \(-\)15 \({}^{\circ}\)C & 98.13\% & \(-\)36.99\% & 98.15\% & 74.02\% \\ T\({}_{\text{c}}\) = 50 \({}^{\circ}\)C-T\({}_{\text{e}}\) = \(-\)5 \({}^{\circ}\)C & 85.40\% & \(-\)50.99\% & 85.40\% & 54.60\% \\ T\({}_{\text{c}}\) = 50 \({}^{\circ}\)C-T\({}_{\text{e}}\) = 5 \({}^{\assuming a mean electrical efficiency of 12% [48] and mean solar irradiation of 800 W/\({}^{2}\). On the other hand, about 135 m\({}^{2}\) of evacuated tubes are needed for covering the heat input demand of the system with the absorption chiller, if a collector efficiency of 60% [43] and 800 W/m\({}^{2}\) of solar irradiation are assumed. The previous simple calculations are in relation to an operation with a refrigeration load of 100 kW at the typical case of T\({}_{\rm e}\) = -15 \({}^{\circ}\)C and T\({}_{\rm c}\) = 40 \({}^{\circ}\)C. However, it has to be said that the use of solar collectors increase the investment cost of the system and thus it is something that it has to be taken into consideration. In the future, there is a need for detailed studies that can optimize financially the suggested configurations and simultaneously to take into account the environmental gain by the reduction of grid electricity consumption.