*4.1. The Assessment of PV System Simulation*

According to the results of the simulation of the PV system, yearly average values of PV electricity (AC) delivered by the total installed capacity of a PV system were found to be 1843 kWh/kWp. Figure 11 shows the distribution of hourly electricity production values of the designed PV systems by all months. As seen in Figure 11a, the system capacity is 25 MW and the maximum monthly electricity production is between 16 and 19 MWh. The maximum electrical energy requirement of KAU hospital will be approximately 25 MWh. The energy generation amount of the PV system for a capacity of 25 MW was less than the hourly electricity requirement of the hospital. As seen in Figure 11b, when the system capacity is 35 MWh, the maximum electricity generation is approximately in the range of 23 to 26 MWh. Therefore, it cannot meet the hourly energy needs of the hospital in some months. Figure 11c shows that the system capacity is 45 MW and there is an exceeding production level of the hourly maximum electrical energy requirement of the hospital in all months. In case the electricity produced from the PV system is more than the electricity consumption of the hospital, the excess production is given to the local electricity grid (on grid PV system). When there is no production of the PV system, the electricity need of the hospital is met by the local electricity grid.

**Figure 11.** Average hourly profiles of total photovoltaic power output for; (**a**) 25 MW of PV capacity, (**b**) 35 MW of PV capacity, (**c**) 45 MW of PV capacity.

In all PV designs, the highest electrical energy production during the year was determined in March. The daily distribution of electrical energy production values of all PV systems in March are shown in Figure 12. In addition, the graphs show the hourly electrical energy consumption profile of the hospital for an average day of 2019.

**Figure 12.** Average hourly profiles of total photovoltaic power output in March for 25 MW of PV capacity, 35 MW of PV capacity and 45 MW of PV capacity.

As seen in Figure 12, when the system capacity is 25 MW, the maximum electricity generation is approximately 20 MWh. The energy generation capacity of the PV system with 25 MW is below the hourly electricity requirement of the hospital. On the contrary, as it is seen in Figure 12 when the system capacity is 35 MW, the maximum electricity generation is approximately 27 MWh. The PV system produces the electrical energy needs of the hospital between 12:00 and 14:00 h. The PV system of 45 MW capacity can meet the electrical energy requirement of the hospital between 10:00 and 16:00 h, and some extra energy is produced.

Figure 13 shows the ratio of meeting the hourly electricity requirement of the hospital with energy generated from the PV system by all months. This ratio is called the selfsufficiency value of the PV system. For example, if the self-sufficiency ratio (SSR) is 30%, it means that 30% of the electrical energy requirement is produced from the PV system. On the other hand, self-consumption indicates that the entirety of the energy produced from the PV system is consumed instantly. This system does not have any storage units and are not fed to the local electricity grid. As it is seen in Figure 13, the self-sufficiency profile is similar in all capacities. Among the distribution of SSR data by month, the lowest performance was observed in February, but the highest performance was observed in May.

Table 1 presents the self-sufficiency ratio of PV systems for monthly and yearly periods. The highest performance was observed in May and this ratio was 31% for PV25, 37% for PV30, 43% for PV35, 50% for PV40, 56% for PV45, 62% for PV50, 93% for PV75 and 124% for PV100. According to the annual simulation results given in Table 1, the self-sufficiency ratio of the PV system for the KAU hospital is found as 24% for PV25, 29% for PV30, 34% for PV35, 39% for PV40, 44% for PV45, 48% for PV50, 73% for PV75 and 97% for PV100.

The annual total electricity consumption value of the KAU hospital for 2019 was 190.042.560 kWh. Figure 14 shows the annual electricity generation distribution of PV systems with different capacities for an average day.

Figure 15 presents the total annual electricity generation of the PV systems, and its comparison with the annual total electricity consumption of the KAU hospital. SSR is also given as a percentage in Figure 15. When the simulation results are analyzed, it is determined that the PV system capacity is 40 MW according to the self-consumption model for the KAU hospital. Based on this self-sufficiency model, the capacity of the PV system is considered 100 MW.
