High penetration of Electric Vehicles (EV) into power grids can enforce major challenges on efficient operation of the system. The solution process of Optimal Reactive Power Dispatch (VAr) which allocates the generator outputs can be either exacerbated or improved. The conventional VAr algorithm is thus reformulated, encompassing EV's operational constraints. As a result, VAr-EV optimization algorithm builds up that minimizes total dispatch costs while taking into account a plethora of system-wise, unit-wise and spatial constraints for a daily operation. Simulation results exhibited that the proposed VAr-EV effectively improves the total dispatch costs and an efficient use of generation sources. However, it can be done by propitious shifts in generation plan from peak to off-peak hours as well as the EV dual operational mode (charging/discharging) advantages. Further, the obtained results represents that employing Newton Raphson (NR) load flow calculation instead of approximated loss techniques can procure an accurate and precise solution, which can also offer a close observation on system status following small breezes in operation. Based on the results, the integration of the EVs into the grid can immensely enhance the socio and techno-economic aspects of the system operation.