## 4 Results and Analyses of the Numerical Application of Global Cost and Carbon Impact of the PVCS
### Analyses of Action Levers to Reduce the Carbon Impact of the PVCS  
To identify the action levers required to reduce the carbon impact, the most emitting positions within the PVCS have been identified. It is then necessary to determine these levers. Once these levers are determined, it is sufficient to reduce their carbon emission coefficient or their carbon impact. This reduction relies on recycled materials and newer data. Once the component's carbon impact is reduced, the new carbon impact of the PVCS is compared to that of the initially considered PVCS and PGCS, to show the gains obtained. According to the chart pie shown in Figure 5, the most impactful element, in terms of carbon impact, is the PV system, which emits 57% of the total carbon impact of the PVCS. The second most impacting element is infrastructure, which emits 18%. The power grid is not considered for estimating action levers that reduce carbon impacts. Therefore, the other components of the PVCS are considered to determine the levers of action. Figure 6 shows the distribution of the carbon impact of the PVCS without the power grid. Without considering the carbon impact of the power grid, the most impactful element in terms of carbon impact is the PV system, which emits 68% of the PVCS carbon impact. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**PVCS** & & & **Imp (kgCO2,eq)** \\ \hline \multirow{8}{*}{**PV system**} & & PV panels & 37,996 \\  & PV system & Inverter & 1501 \\  & components & Support & 7087 \\  & & Wiring & 1962 \\ \cline{2-4}  & \multirow{2}{*}{Site} & Installation & 1 \\  & & Uninstallation & 1 \\ \cline{2-4}  & Maintenance & Cleaning & 23 \\  & & Servicing & 424 \\ \hline \multirow{2}{*}{**Charging terminals**} & Maintenance & & 1023 \\ \cline{2-4}  & Fabrication & & 1095 \\ \hline \multicolumn{2}{c}{**Li-Ion battery**} & & 5869 \\ \hline \multicolumn{2}{c}{**Infrastructure**} & & 15,439 \\ \hline \multicolumn{2}{c}{**Public grid**} & & 13,540 \\ \hline \multicolumn{2}{c}{**Total**} & & 85,961 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Summary table of the carbon impact of each component of the initially considered PVCS. The second most impacting element is the infrastructure, which emits 21%. Next, comes the stationary storage with 8% and the charging terminals with 3%. Since the PV system is made up of many other components, it is then necessary to determine which components emit the most within the system. As shown in Figure 7, the PV panels are the most impactful elements in terms of carbon impact. Their carbon impact is about 78%. Indeed, the PV panels' manufacturing is the most energy-intensive step. For example, a large quantity of energy is used to convert silica sand into high purity silicon. The main action lever in order to reduce the carbon impact is then the PV panels, thereby reducing the impact of the PV system, and therefore of the PVCS. According to the aforementioned analysis, the PV panels and infrastructure will be considered. The carbon impact of new PV panels decreased sharply over the years, due to the use of less carbon emitting processes and materials during manufacture, and their improved efficiency. In this study, the values of emission coefficients used to calculate the carbon impact of the considered PVCS came from the Ecoinvent database and the study carried out by  
Figure 5: Distribution of the impact carbon of the PVCS. Figure 6: Distribution of carbon impact of the PVCS without considering the power grid. Figure 7: Distribution of carbon impact of the PV system. NREL in the LCA harmonization project [29], which explains an emission coefficient of 0.04 kgCO2,eq/kWh for PV panels. Thus, in order to calculate the reduction of the carbon impact, the emission coefficient of the PV panels will be changed. In this framework, the reduction of the carbon impact of PVCS is analyzed according to four scenarios.