The increasing penetration of plug-in electric vehicles (PEVs) in power systems has introduced new challenges to system operators in managing the generation and load balance. Meanwhile, the integration of renewable energy sources (RES) into the grid has brought the system greener but also introduced variability and uncertainty in power generation. This paper proposes an optimal unit commitment strategy for PEVs in the presence of an RES to minimize operational costs and enhance the reliability of the power system. The proposed strategy uses a case study of a 24-bus IEEE system of power system with 10 generating unit 50 MW RES generation profiles for 50,000 PEVs with an average battery capacity of 30 kWh with varying time horizon PEVs behave source and load. The strategy involves the status of the generating unit, running cost of generating unit, cost of PEVs, cost of RES generation with constraint of generating unit, PEVs, RES by application of mixed-integer linear programming (MILP) model using Gurobi and YILMIP solver that takes into account the charging demand of PEVs, the variability of RES generation, and the operational constraints of the system. Simulation results demonstrate that the proposed strategy can effectively manage the power system with high PEV penetration and RES variability, achieving significant cost savings by maintaining optimized unit commitment and improved system reliability.