## 3 Methodology
### Economic Analysis  
The decision was made to focus on a single solar charging station, specifically one located at LuLu's Marketplace. The initial analysis identified the need for a network of stations across 17 different zones. By concentrating on one strategically selected station, this study aims to provide a detailed and thorough investigation of the economic, technical,  
Figure 4: LuLu’s Hypermarket location (**a**), and plan view before the PV unit installation (**b**). and environmental parameters. This approach not only allows for a more manageable and focused analysis but also serves as a representative model. The findings and methodologies applied to this single station can then be extrapolated or adapted for broader application across the proposed network, offering valuable insights for the potential scalability and replication of the project in other zones or similar urban contexts. In the economic analysis of the solar charging station for EVs, the LCOE and net present value (NPV) metrics are utilized to evaluate the project's financial viability. Given the long-term nature of the solar charging station project, the real LCOE is employed in this study. Equation (23) outlines the methodology for calculating the LCOE:  
\[LCOE(real)=\frac{-C\omega-\frac{\sum_{i=1}^{N}C\pi}{(1+d_{\text{nominal}})^{ \pi}}}{\frac{\sum_{i=1}^{N}Q\pi}{(1+d_{\text{real}})^{\pi}}} \tag{23}\]  
where:  
C\({}_{0}\): Equity investment (USD),  
C\({}_{n}\): Project's cost in n years,  
d\({}_{\text{real}}\): Real discount rate (%),  
d\({}_{\text{nominal}}\): Nominal discount rate (%), see Equation (24),  
N: Analysis period in years,  
Q\({}_{n}\): Amount of electricity generated by the plant in year n. (kWh). \[NominalDiscountRate=\left[\left(1+\frac{RealDiscountRate}{100}\right)\times \left(1+\frac{InflationRate}{100}\right)-1\right]\times 100 \tag{24}\]  
The NPV is a popular metric used to gauge a project's cost-effectiveness. The cost-effectiveness metric known as the NPV of a project combines both cost and income. Equation (25) can be used to determine the NPV. A project is said to be economically viable if its NPV is positive, as opposed to being unviable if it is negative. \[NPV=\sum_{i=0}^{N}\frac{(Cash\ flow)i}{(1+d)^{i}} \tag{25}\]  
N is the number of years that the installation will last, and the installation's lifespan is represented by the I; I = 1 to 30. The PBT will be estimated as an economic performance measure, which can be calculated as follows:  
\[PBT(Years)=\frac{Initial\ Cost}{\left(\ E_{\ grid\ (\frac{kWh}{Wh})}*Value(SR\ or\ USD\ /kWh))\ -C_{O\&M\ (SR\ or\ \frac{USD}{kWh})}\right)} \tag{26}\]  
The concept of the return on assets (ROA) is pivotal for assessing the financial efficiency of companies involved in PV system design and implementation. The ROA is calculated using the following equation:  
\[ROA=\frac{Net\ Income}{Total\ Assets} \tag{27}\]  
* Net income represents the profit of the company after all the expenses and taxes have been deducted. * Total assets encompass the sum of all the assets owned by the company, including both current assets and fixed assets like PV equipment and infrastructure. The amount that lowers a project's NPV to zero is known as the discount rate. It is the anticipated compound annual rate of return on a project or investment. The PV \(*\) SOL is used to estimate an investment's internal rate of return. According to the study, the Saudi Central Bank reports an interest rate of 2.4% and an inflation rate of 2.5%. All the same, a 4.5% discount rate is expected for the KSA. The project would take 30 years to complete, which is equivalent to the life cycle of a PV module. Debt would not be included in the project's capital costs. On average, inverters have a 15-year lifespan and can be recovered for 30% of their original cost. In December 2019, a regulation was produced by the Electricity and Cogeneration Regulatory Authority [53]. The installation, maintenance, and operation of small solar PV energy systems in all installations are certified by this legal framework.