## 4 Results and Discussion
### Comparison of Various PV Tracking Techniques on the Technical Aspect
In terms of yearly total energy sold back to the grid, the VSAT is sold 561.280 MWh/year annual energy, and FTSP, HSAT, and DAT are ranked next corresponding to 321.537 MWh/year, 37.115 MWh/year, and 36.470 MWh/year, respectively. As shown in Figure 13b. Figure 12: (a) Monthly average energy purchased from the grid for different PV tracking techniques, (b) accumulatively annual energy purchased from the grid for different PV tracking techniques. Saudi Arabia is the 2 nd largest oil producer in the world, the basic source of electricity generation is fossil fuel. It causes major environmental concerns, as literature reported that Saudi Arabia participated with 2.8% of global emission and 56.34% of internal CO2 emission because it was more reliant on oil for electricity generation and heating production. Which pushed Saudi Arabia to make strategic to install 41 GW of solar energy by the time of 2032, with the total cost 108.9 billion [79]. In this context, a PV tracker can play a vital role to capture solar irradiation as much as possible and help to increase PV productivity, PV penetration, and lead to minimize reliance on the grid that can reduce CO2 emission. This is discussed and proved in our study for all selected PV tracker design. Figure 14 illustrates that VSAT is achieved the lowest CO2 emission, followed by FTSP, HSAT, and DAT with corresponding values of 255,432 kg/year, 286,144 kg/year, 397,279 kg/year, and 398,063 kg/year, respectively. The reason is that the VSAT technology helps purchase the lowest energy from the grid and sell the highest energy as discussed earlier in Figures 12b and 13b. The discussion of the technical properties of grid-connected hybrid energy system (PV-FC) for the four major PV tracking techniques highlight that the vertical single axis tracker (VSAT) is the best option for grid-connected hybrid energy system (PV-FC) in the location of this study. under the effect of VSAT technology which corresponded to 3,441,850$, 0.1543 $/kWh, respectively. The HSAT is ranked 2 nd in terms of NPC and 3 rd regarding LCOE which corresponded to 3,800,309$, 0.2739 $/kWh, respectively. The FTSP is ranked 3 rd in terms of NPC and 2 nd regarding LCOE which obtained 3,918,589$, 0.2124 $/kWh, respectively. The DAT comes last given the highest NPC, LOCE which appreciated 3990264$, 0.2878 $/kWh, respectively. With VSAT taken as base case achieving the lowest LCOE, it was compared with the LCOE of other PV tracker in percentage rate, as illustrated in Figure 15b. The figure demonstrated that the VSAT can decline 37.65%, 77.5%, and 86.5%, of LCOE than FSAT, HSAT, DAT, respectively. According to the energy flowing from and to the grid which are reported early in Figures 12a and 13a, the net purchased energy which is defined as purchased energy minus sold energy. If the net purchased energy is minus, it means the sold energy is more than is purchased and vice versa. On the other hand, the energy charge is the fees charged to deliver the electricity from and to the grid, if the value is minus, it means the fees of sold energy are more than the fees of purchased power. Through estimations of net purchased energy for various PV tracking technology, it can significantly notice which PV tracker achieved more revenues that were the reason for reduced LCOE. Through one-year net purchased energy estimation for various PV tracking technology, the highest revenues obtained by VSAT represented to \(-\)303.264 MWh net purchased energy corresponded \(-\)14237.8$ energy charge based on tariff policy which has been discussed early in section (2.2.7), followed by FSAT technology for which the net purchased energy was \(-\)32.499 MWh corresponding to \(-\)1506.16$ energy charge. And HSAT is coming next, where appreciated net purchased energy 364.180 MWh corresponded to 21297.11$ energy charge. In addition, DAT is ranked last, where obtained 365.617 MWh that is the highest net purchased energy corresponded to 21377.66$ energy charge.