## 5 Simulation Results and Analysis
### Calculation of Optimal Component Size of System  
According to Table 7, the system configurations corresponding to the four scenarios are as follows:  
* Configuration 1: The system does not contain any components;
* Configuration 2: The system only contains PV systems;
* Configuration 3: The system contains PV system and lithium-ion battery ESSs;
* Configuration 4: The system contains all components. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Algorithm** & **Rule-Based** & **GA** & **DP** \\ \hline Degradation cost & 895.4 & 866.1 & 857.9 \\ Electricity cost & 6091.5 & 6063.2 & 6058.7 \\ Operation cost & 6986.9 & 6929.3 & 6916.6 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Performance comparison of three algorithms. Figure 14: Comparison of battery degradation curves of three algorithms. The system cost under the configurations corresponding to scenarios 1 and 2 is simulated. Figure 15 shows the simulation results. Compared with configuration 1, a suitable sizing of the PV panels can effectively reduce system the MOCT. When \(C_{\text{PV}}\) = 11 kW, the OCT under configuration 2 is the lowest, i.e., CNY 9188.8. Compared with CNY 11,988.1 when not purchasing the PV panels, the OCT is reduced by 23.35%, but compared with configuration 1, the EFF is reduced by 40.77%. Moreover, when the PV sizing is in the range of 5-20 kW, the annual OCT changes are not obvious, and the EFF shows a significant downward trend. This is because the particularity of the selected climate makes it impossible for fixed-capacity photovoltaic panels to perfectly match summer and winter at the same time. If both the OCT and EFF indicators are considered at the same time, a critical point of 5-7 kW, where there is no significant change in the OCT or a significant decrease in EFF, is selected as the reasonable capacity configuration. It is possible to further reduce the system OCT and improve the EFF by configuring a part of the ESS. If the ESS contains only lithium-ion batteries, the battery degradation cost can be high. Therefore, considering the simultaneous use of SCs and lithium-ion batteries, configurations 3 and 4 are simulated. Figure 16 shows the simulation results. As the PV sizing increases, the excess power generation increases, and the battery life is reduced. SCs can alleviate this situation; however, the expensive price of the SCs leads to limited sizing configurations, and the degradation of the battery is also limited. Increasing the battery sizing can also slow down battery degradation. The simulation results show that the SC can reduce the battery degradation by approximately three times, except for the case when the PV sizing is less than 5 kW and the excess PV generation is low. Based on \(P_{\text{demand}}\) shown in Figure 10, the greater the battery sizing, the lower the charge and discharge rates of the battery, resulting in a small number of SCs failing to smooth and increase battery charge and discharge power. According to Equation (15), the battery degradation cost is mainly determined by the battery charge and discharge amount and the battery charge and discharge rates. When the lithium-ion battery sizing is much greater \begin{table}
\begin{tabular}{c c c c} \hline \hline
**System Components** & **PV** & **Battery** & **SC** \\ \hline Scenario 1 & \(\times\) & \(\times\) & \(\times\) \\ Scenario 2 & \(\surd\) & \(\times\) & \(\times\) \\ Scenario 3 & \(\surd\) & \(\surd\) & \(\times\) \\ Scenario 4 & \(\surd\) & \(\surd\) & \(\surd\) \\ \hline \hline \end{tabular}
\end{table} 
Table 7: System configurations for the four scenarios. Figure 15: Annual MOCT of configurations 1 and 2.  
than the SC sizing, SC has a limited effect. Therefore, it is necessary to simulate the system economy under different capacity configurations. Figure 17 shows the simulation results. As shown in Figure 17, when the PV sizing is 5 kW or less, configuration 2 is superior to other configurations, and the use of the ESS increases the OCT. It is unreasonable to use the ESS in the system at this time.