## 4 Results and Discussion
### Comparison of Various PV Tracking Techniques on the Technical Aspect  
The technical properties of the grid-connected hybrid system (PV-FC) were carefully examined for different PV tracking techniques. The monthly average of PV production is illustrated in Figure 10. It can obviously be seen that both VSAT and FTSP are dominated in terms of achievement of high PV power production. However, VSAT is noticeably superior except in the period April-August. On the other hand, DAT and HSAT come next, and it can be observed that DAT is helped for product high power than HSAT except in the period April-August. In terms of yearly total PV power production, as can be observed in Figure 11a, the VSAT has the highest power generated followed by FTSP, DAT and HSAT corresponded of 2078.265 MWh/year, 1640.007 MWh/year, 1595.342 MWh/year and 1556.716 MWh/year, respectively. In other words, it can be noticed that the VSAT produced 26.7%, 30.2%, and 33.5% more power than FTSP, DAT and HSAT, respectively. The excess power occurred in the system due to the production from PV surpassing consumption. In such a microgrid hybrid renewable power system the excess power is usually dumped or can be utilized for further application. However, in this study the excess power will be injected back to the utility for further revenues. In this model the highest excess energy belongs to the DAT technique  
Figure 11: (**a**) PV energy production of one year for different PV tracking techniques, (**b**) excess energy for different PV tracking techniques, (**c**) PV penetration for different PV tracking techniques. Figure 10: Monthly average-hourly data of PV production for different PV tracking techniques. and corresponded to 625.451 MWh/year, the HSAT, VSAT, and FTSP are ranked sequentially next, and corresponded to 592.921 MWh/year, 381.284 MWh/year, and 243.546 MWh/year, respectively, which can be depicted in Figure 11b. PV penetration is an important criterion taken into account for discussing this. It is defined as the ration of peak PV power to the peak load, here in grid-connected hybrid system (PV/FC), the maximum PV penetration is given by VSAT which was 772%, followed by DAT, HSAT, and FTSP corresponding to 674%, 595% and 563%, respectively, as can be seen in Figure 11c. In other words, 209% is the difference between the highest value belonged to the VSAT and the lowest belonged to the FTSP, and between them, the significant role of the PV tracking techniques for increasing PV energy penetration to the grid can additionally be noticed. Additionally, it is more interesting to discuss the energy purchased and sold from and to the grid for each month, taking into account four considered PV tracking techniques. The Figure 12a shows the monthly average energy purchased from the grid, the curves demonstrated that DAT, and HSAT achieved the highest energy purchases in the calendar year, followed by FTSP and VSAT, respectively. It can also be seen that the highest purchased energy is in the summer, where the high load demand reported in this period, as discussed early in Section 3.3. To clearly distinguish, the yearly total energy purchasing is explicitly depicted in Figure 12b. The figure shows that the DAT is given the yearly highest purchased energy estimated at 402.087 MWh/year followed by HSAT, FTSP, and VSAT corresponded of 401.295 MWh/year, 289.038 MWh/year, and 258.016 MWh/year, respectively. On the other hand, the monthly average sold to the grid is illustrated in Figure 13a. It can be seen that VSAT obtains the highest monthly average energy sold back to the grid. FTSP comes next, and where both HSAT and DAT have demonstrated the lowest sold energy, there was little difference that can be noted in terms of annually total sold energy. Additionally, it was noticed that, the lowest sold energy in the summer, where the load energy was high demand at this period.