## 3 Results  
According to the methodological approach explained before, hourly energy simulation was carried out. The annual AC energy output is equal to 4,901,879 kWh (Figure 6). Figure 7 reports the monthly energy output from the PV system. The highest energy consumption, equal to 735,662 kWh, is achieved in June, whereas the lowest one, equal to 115,823 kWh, is achieved in November. Estimating the total electrical loads during the stadium events, it was possible to estimate the energy sent to the battery. It amounts to 2,112,000 kWh (176,000 kWh per month). Thus, the annual AC energy output, exported to the public grid, is equal to 4,421,879 kWh. Figure 5 reports the monthly energy output fed into the utility grid.  
Regarding the results for energy produced by the PV system in terms of household utilities' energy demand, the electrical energy output could supply the energy demand of 634 household utilities, equal to 1325 people, or 1385 non-domestic utilities. The summary results in terms of satisfied energy demand are shown in Table 4. Similarly, regarding the results for energy produced by the PV system in terms of the number of streetlights served in the city of Rome, the electrical energy output could supply the energy demand of 15,008 lamps. The summary results in terms of satisfied energy demand are shown in Table 5.  
Figure 6: Annual AC energy in Year 1 (kW).  
\begin{table}
\begin{tabular}{c c c} \hline
**Total Number of Lamps** & **Average Distance between** **Lamps (m)** & **Total Annual Energy Consumption for** **Lighting (MWh)** \\ \hline
226,728 & 31.39 & 66,801 \\ \hline \end{tabular}
\end{table}
Table 3: Characteristics of the public lighting network in Rome according to [46].  
The initial cost is calculated as EUR 5,413,689.95. Figure 8 illustrates the cash flow performance of the solar PV system, which considers the discount rate equal to 4.64% as given in [47]. The annual cash flow is observed for 25 years, and the simple payback period is 14 years. The net present value (NPV) is calculated as EUR 2,644,605.70, which provides a profitability index (PI) of 0.49. The profitability index compares the NPV with the initial investment cost. A profitability index greater than zero signifies that the project is profitable.  
\begin{table}
\begin{tabular}{c c c} \hline \hline  & **Number of Supplied** &
\begin{tabular}{c} **Percentage of Coverage of the** \\ **Total Energy Demand by the** \\ **PV System (\%)** \\ \end{tabular} \\ \hline Domestic electrical & 2084 & 0.16\% \\ consumption & 215 & 0.07\% \\ \hline \hline \end{tabular}
\end{table}
Table 4: Energy output from PV system to domestic and non-domestic utilities.  
Figure 8: Cash flow performance.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Total Length of** & **Number of** & **Percentage of Coverage of the** \\
**Illuminated Roads (km)** & **Supplied Lambs** & **Total Energy Demand by the** \\ \hline
471.1 & 15,008 & 0.07\% \\ \hline \hline \end{tabular}
\end{table}
Table 5: Energy output from PV system to streetlights.  
Figure 7: Monthly energy output from PV system (**a**) and from PV system to grid (**b**).  
According to emission factors of greenhouse gases from the electricity sector for the generation of electrical power reported by the ISPRA Report 2021 [46], the estimated annual CO\({}_{2}\) emission reduction is equal to 1266.15 tonCO\({}_{2}\).