Abstract The sustainability of modern human civilization is significantly concerned with enhancing sustainable energy resources. Vertical-Axis Wind Turbines (VAWTs) gained a promising impact on the global energy mix due to their belief in sustainable energy solutions. This paper presents an integrated study of the dynamic performance and fatigue-life characteristics of the optimized Savonius-rotor VAWT composite blades. Furthermore, this paper introduces an experimental validation, numerical modeling, and visualization/verification study of the optimized VAWT composite blades and assesses its impact on the whole performance of the optimized Savonius VAWTs. Four combination levels of the optimal settings of the S-VAWT composite blade configurations are designed, modeled, simulated, and fabricated of Carbon/Glass—Polyester. The modal parameters such as natural frequency, mode shape, and damping factor are investigated using fast Fourier transformer (FFT) analyzer. The numerical finite element models (FEM) are generated to model, visualize, simulate, and predict the dynamic nature and fatigue-life characteristics of the optimal S-VAWT composite blade configurations. A correlation between the experimental and numerical results is established. The study findings highlight the significant impact of VAWT composite blades in enhancing the dynamic performance and fatigue-life characteristics of Savonius VAWTs. Furthermore, a small damage percentage of 2.8% predicted by the finite element analysis (FEA) for the optimal S-VAWT composite blade configuration validated the sustainability of the VAWT composite blade configurations in dynamic loading conditions.