Renewable energy has a huge potential in the upcoming era due to the scarcity of fossil fuels. Taking this into account a 2D numerical simulation has been carried out to predict the performance of a five-bladed Darrieus H-type vertical axis wind turbine (VAWT). To this aim, a computational setup is built on a finite-volume method discretization of two-dimensional unsteady Reynolds-averaged Navier-Stokes equations (RANS), with k-ε turbulence modelling. The analysis is carried out adopting sliding mesh technique and validated against the experimental results. Using this approach the proposed model is solved to predict the lift and drag coefficients, the torque generated, the power coefficients at different tip speed ratios (TSR). Finally, the investigation concludes by validating the overall performance and the power output of the five-blade (NACA 0018) vertical axis wind turbine in freestream condition. The performance efficiency of the current analysis is compared with experimental three bladed (NACA 0018) wind turbine. The turbine achieves a maximum peak power coefficient (Cp) at higher wind speed and tip speed ranging from 2.5 to 3.5. This research advances on understanding the design optimization of small or medium scale VAWT with associated power rating. © 2017 Int. J. Mech. Eng. Rob. Res.