**5. Results**

Table 5 and Figure 5 list the optimal configuration composed by PV arrays, wind turbines, a converter, and batteries. Table 6 shows the total and annual costs of the components in the simulation. The combination of 12,780 kW-capacity of the PV arrays, 17,965 battery units with a 1525 kW-capacity of the electric converter is suggested to respond to the electricity demand of Chiang Mai University.

**Figure 5.** The suggested configuration (created by the authors).

**Table 5.** Optimal configuration for Chiang Mai University (created by the authors).


**Table 6.** Total and annual costs of the optimal configuration (created by the authors).


The optimal configuration shows \$5,168,399 of the annual costs with \$0.728 per kWh of the COE level. The cash flow is introduced in Figure 6. The annual electricity production was estimated to be 20,768,330 kWh. Figure 7 presents the monthly electricity production. The monthly PV power production and battery state of charge are presented in Figures 8 and 9, respectively.

**Figure 7.** Monthly production of electricity from the suggested configuration (created by the authors).

**Figure 8.** Monthly PV power production of the suggested configuration (created by the authors).

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**Figure 9.** Monthly battery state of charge of the suggested configuration (created by the authors).

The key findings from the simulation results in the current study could be introduced as follows. First, the combination of PV array-batteries-converter was proposed for Chiang Mai University. Second, the suggested configuration from the simulation shows \$70,147,828 of the total NPC level with \$0.728 kWh of the COE level. Third, the optimal configuration meets the 100% renewable fraction, because the purpose of this study was to present independent renewable electricity generation systems for Chiang Mai University.

Moreover, there are the notable amounts of the annual reduced environmental pollutants of the proposed configurations, instead of using the current grid system. 4,487,738 kg of CO2, 19,456 kg of SO2, and 9515 kg of NO and NO2 cannot be annually emitted by employing the proposed configuration in this study.
