Nowadays, the generation of energy from wind power has grown significantly as one of the most important renewable energy sources in the world today. In this study, the performance of a multistage vertical axis wind turbine (VAWT) has been assessed through 3D computational fluid dynamics (CFD) simulation approach based on K-omega shear stress transport (SST) models using the ANSYS Software. The inexpensive, omnidirectional, compact and easy to assemble Savonius rotor has been applied in this study along with the multistage-rotor concept. Multistage-rotor is where one stage of the rotor is placed on top of another stage of the rotor. The wind speed tested ranges from 5 m/s to 11 m/s at a tip-speed ratio (TSR) ranging from 0.2 to 1.0. The findings for torque and power with different operating wind speed demonstrated that as the wind speed increases at constant tip-speed ratio (TSR), the torque also increases; meanwhile, the torque coefficient decreases. However, when the wind speed increases along with the increasing TSR, the power generated increases. Meanwhile, the performance power coefficient has a directly proportional relationship with the TSR and an inverse relation with the wind speed tested
