Synthetic jets (SJs) present a promising flow control technique for improving wind turbine aerodynamic efficiency by mitigating boundary layer separation on airfoils. However, the precise quantification of their impact on wind energy generation remains elusive. This study investigates the effects of SJs on a vertical-axis wind turbine (VAWT) airfoil through numerical analysis. Utilizing a single, validated SJ model, computational fluid dynamics (CFD) simulations were conducted to assess the aerodynamic performance of the SJ-modified airfoil at various angles of attack. The results demonstrate that SJs effectively delay the onset of stall, leading to a significant increase in lift coefficient at high angles. This translates to a potential for enhanced power generation when extrapolated to full VAWT simulations using the actuator line model. CFD-actuator line simulations of the VAWT incorporating the SJ-modified airfoil data reveal an improvement in turbine performance, with an estimated power increase of approximately 17%. Furthermore, the SJs use may influence the wake behavior, potentially leading to: • Reduced wake turbulence: By delaying stall and maintaining attached flow, SJs could decrease the generation of turbulent eddies in the wake, improving downstream flow conditions. • Modified wake velocity profiles: The localized energy addition from the SJ could alter the velocity distribution within the wake, potentially impacting the power output of downstream turbines in a wind farm. Further investigation into the impact of SJs on the wake is crucial for fully understanding their potential benefits and drawbacks in VAWT applications. This study provides a valuable foundation for future research efforts in this area.