Photovoltaic (PV) solar power systems are widely utilized in various large and medium-scale commercial and residential applications. A major operational issue affecting the quality of power supply is shading and partial shading of the PV modules. This phenomenon is largely attributed to moving clouds and shadows of nearby buildings or obstacles, which causes the shading of the PV arrays, hence resulting in reducing the output power below the required power. While the majority of previous research concentrated around using bypass diodes to mitigate power inefficiency due to shading, few work addressed the side effects of this technique on system components. Such side effects are best understood in view of the inaccurate selection of the required power inverter with Maximum Power Point Tracking (MPPT). This research investigates the selection of inverter and module optimum ratings, with the aim to reach maximum protection of the system power components. This process is done using a developed system for commercial buildings. The investigation is performed using computer software simulation of changing the PV solar power system components ratings, while using a bypass diode, and then examining the efficiency performance. Results of the optimum ratings are then analyzed. Photovoltaic (PV) solar power systems are widely utilized in various large and medium-scale commercial and residential applications. A major operational issue affecting the quality of power supply is shading and partial shading of the PV modules. This phenomenon is largely attributed to moving clouds and shadows of nearby buildings or obstacles, which causes the shading of the PV arrays, hence resulting in reducing the output power below the required power. While the majority of previous research concentrated around using bypass diodes to mitigate power inefficiency due to shading, few work addressed the side effects of this technique on system components. Such side effects are best understood in view of the inaccurate selection of the required power inverter with Maximum Power Point Tracking (MPPT). This research investigates the selection of inverter and module optimum ratings, with the aim to reach maximum protection of the system power components. This process is done using a developed system for commercial buildings. The investigation is performed using computer software simulation of changing the PV solar power system components ratings, while using a bypass diode, and then examining the efficiency performance. Results of the optimum ratings are then analyzed.