This study presents a comprehensive static structural analysis for validating deformations and stress limits (von Mises) under rotational velocity in a high-speed flywheel energy storage system. Finite Element Analysis (FEA) was conducted to evaluate the structural integrity of the flywheel system under various loading conditions. The analysis revealed displacement measurements ranging from 0.00 mm to 0.016 mm, demonstrating exceptional structural stiffness. Von Mises stress analysis indicated a maximum stress of 8.335 MPa at the most stressed point and a minimum of -0.086 MPa, confirming that plastic behavior is not predicted to occur. Response Surface Methodology (RSM) was employed to optimize the flywheel geometry, with ANOVA revealing significant model terms for stress (F-value: 1.84), mass (F-value: 32451.30), displacement (F-value: 2.65), and energy (F-value: 955.46). The optimal configuration was determined to be an outer diameter of 400 mm, thickness of 50 mm, and angular speed of 236.17 rad/s, resulting in a von Mises stress of 0.0190169 MPa, mass of 31.97 kg, and energy storage capacity of 18, 000 J. These findings validate the structural soundness of the design and its suitability for fuel-less energy storage applications.