The increasing demand for electrical energy, the increasing cost of oil and fossil fuels, and the environmental pollution they cause have prompted researchers in various fields to explore alternative solutions. In recent years, renewable energy, particularly solar energy, has received significant attention due to its free and clean nature. This is particularly important in regions with favorable conditions for solar energy as an alternative source of electricity generation. This paper presents a MATLAB/Simulink simulation of a grid-connected electrical system with a variable load. A Static Synchronous Compensator (STATCOM) was implemented, integrated with a pv system and a battery, and connected to the electrical grid to determine its ability to maintain voltage stability and regulate reactive power within safe limits. The behavior of active and reactive power, as well as voltage fluctuations, was analyzed with and without the Static Synchronous Compensator (STATCOM) under load variations and fault conditions. Fault scenarios were developed to evaluate the impact of the Static Synchronous Compensator (STATCOM) on grid stability and improved power performance. The results showed that the STATCOM effectively reduced fluctuations, enhanced active and reactive power response, and maintained grid voltage stability, highlighting its pivotal role in ensuring electrical system reliability.