# Potential Study of Solar Thermal Cooling in Sub-Mediterranean Climate
## 4 Economic Feasibility
### Economic Feasibility  
The economic feasibility analysis of solar thermal cooling systems, which require high initial investments, plays a very important role in the assessment of the viability of the project. \begin{table}
\begin{tabular}{c c} \hline
**Component** & **Cost in JD** \\ \hline Absorption chiller & 87,480 \\ Solar field & 102,060 \\ Heat rejection & 19,440 \\ Auxiliaries & 34,020 \\ Total & 243,000 \\ \hline \end{tabular}
\end{table} 
Table 2: Total cost and cost of each of the individual components for the absorption cooling system. Figure 8: Share of absorption system components in the total cost. For assessing the financial feasibility of the system some financial metrics were used in this study; namely the Net Present Value (NPV) and payback period. Net Present Value (NPV) is defined as the difference between the present value of cash inflows and the present value of cash outflows. NPV is used to analyse the profitability of a projected investment. The acceptance criterion for NPV is quite straightforward; when the NPV is greater than zero, the project will be accepted, otherwise, the project has to be rejected. In this study, the system life expectancy is defined through the system components lifespan and maintenance. the feasibility calculations were performed for two scenarios with lifespan over 25 years. The lifespan was chosen according to the evacuated tube's expected life of 25 years, with some literature even expecting a lifespan of 20 years. The energy saving over 25 years was defined through forecasting the amount of electrical energy that would be saved from the solar cooling system of its operation based on the local distribution companies in Jordan. Operating and maintenance cost (O and M) percentage is defined through the changed costs for operating and maintaining the system based on the lifetime of the system. In addition, the annual inflation in O and M cost is defined through the percentage of inflation in the operation and maintenance costs per annum. The operating cost is mainly used to run the auxiliary components of the system; dry coolers, heating, cooling, and chilled water pumps. Figure 9 shows the share of the auxiliary power consumption components of the absorption system. The solar dry cooler (maximum power consumption 7.49 kW) was used to serve a uniform temperature from the hot water circuit. The solar dry cooler is turned on when the hot water temperature from the solar field exceeds 95 \({}^{\circ}\)C and turned off when the hot water temperature falls below 85 \({}^{\circ}\)C. The relative low set points for activating the solar dry cooler also contribute to a higher electrical consumption of the solar dry cooler. The reject-heat pump with an auxiliary power consumption of 3 kW is connected with heat sinks for the absorber and condenser. The dry cooler of the condenser has an auxiliary power consumption of 2.47 kW and the chilled water pump has a power consumption of 2.2 kW. Furthermore, 1% of the auxiliary power consumption was used to run the control boxes for operating the system actuators to a specified and adjustable sequence of operation depending on the operating mode. The results of the Discount Cash Flow financial analysis are illustrated through Figures 10-12. In this study, the interest rate is assumed to be 6%, which is a suitable interest rate in a local commercial  
Figure 9: Percentage share of the auxiliary power consumption components of the absorption system. bank in Jordan. Therefore, a discount rate of 6% is used in the Discount Cash Flow analysis to determine the present value of future cash flows. As shown in Figure 10, the absorption cooling system is deemed as feasible for a COP of 0.79 as claimed by the manufacturer over a lifespan of 25 years. The net present worth is equal to +185,070 JD and the payback period is equal to 10 years. However, the feasibility study of the absorption cooling  
Figure 11: Absorption cooling system cash flow diagram with an average observed COP of the absorption chiller of 0.32.