Practically, the photovoltaic system has an average efficiency of around 15-20%. With this range of value, it is highly recommended for the system to gain the maximum efficiency possible. This paper consists of load-flow study that aims to analyze the optimum location for solar PV implementation by evaluating the voltage drop of the examined system. The study is performed by modeling the power system of the Lombok electrical network. Afterward, a 10 MWp PV solar plant is integrated at several points in either transmission or distribution bus. This study is carried out by the ETAP program to calculate and process the data based on the Newton-Raphson method. The result of the data processing shows that the best interconnection for PV implementation on grid-solar power plan interconnected system located in Lombok is on GI Mantang substation. That 150-kV bus area is the most optimum location to integrate the PV system with the grid system with the voltage drop appeared on that bus is 1.471%.