In this research work, a grid connected solar photovoltaic (PV)-battery energy storage system (PV/BESS) was designed to improve the power supply of Yola north and south. The solar photovoltaic panel model adopted is 100W monocrystalline photovoltaic panel, and the average solar radiation of the study area is 654.40W/m2. The system consists of modeled PV Array, Boost converter model, three-phase power inverter model, step-up power transformer and modeled Phase locked loop. The designed solar photovoltaic model generated 3.40MW of electric power via the step-up transformer, which was integrated into the utility grid of the study area. The output signal of the solar PV array was optimized using boost converter. The inverter inverted the output of the PV array to AC signal, which is connected to step-up power transformer to step-up the three-phase AC voltages to the grid voltages level. PLL was designed for proper synchronization of the solar PV model with the grid without harmonic distortions. The designed solar PV array model was able to supplement the deficit power of 3.40MW to the grid of the study area.