Today, the demand for electrical energy is increasing day by day depending on social life, industrial applications and industrialization. With the increase in energy demand, the importance of the use of renewable energy sources (solar, wind, hydrogen, etc.) has also increased. It is necessary to examine the technical problems that may arise after the incorporation of renewable energy sources into a power system. These technical problems can generally be evaluated together with the name "Power Quality". power quality; It contains many parameters such as harmonics, voltage fluctuation, power factor and flicker. After a solar power plant is included in the power system in industrial companies, a change may occur in the supply voltage, harmonic and power coefficient values. Therefore, the active, reactive and harmonic values of the electrical energy drawn from the network should be constantly monitored. Limit values of reactive / active energy ratios must be within the limits determined by the Energy Market Evaluation Authority. When the reactive loads are proportional to the active loads, the power factor also changes. In this study; The solar power plant, which was measured, was evaluated in terms of reactive/active ratio, harmonic and voltage deviation. As a result of the analyzes made after the power supply was connected in the companies, the problems caused by the loads on the system were determined and solution suggestions were presented.