The primary aim of this paper is to enhance the efficiency of vertical axis wind turbines by incorporating external modifications on the blades, particularly focusing on vortex generators. The research includes an analysis of standard turbine blades to understand their performance and experimenting with various models based on Aspect Ratio (AR). NACA 0012 airfoils were chosen for their favorable lift-to-drag coefficient ratio. The study also acknowledges a lesser focus on start-up characteristics, concentrating instead on overall efficiency improvements. The turbines were modeled in SOLIDWORKS and CATIA, and their analysis was conducted using ANSYS Fluent 17.2 with a shear stress k-ω transport (SST) model and a pressure-based Unsteady Reynolds Averaged Navier–Stokes (URANS) approach. The URANS equations were solved using the SST k-ω turbulence model, and it was observed that turbines with a lower AR, enhanced with vortex generators, exhibited a higher power coefficient compared to those with a higher AR but without VGs. Overall, this research presents significant findings in the field of wind turbine efficiency, particularly using vortex generators on the blades of vertical axis wind turbines, thus offering promising solutions for enhancing the efficiency of wind energy systems.