Electric vehicles are becoming widespread not only in personal use but also in public transportation. In order for electric buses to complete their routes, they need larger capacity batteries. It is crucial that these batteries can supply the necessary energy in operation. On-route chargers are a potential solution for reducing the required battery sizes in electric buses. To achieve this, high power is needed instantly. However, this instantaneous power demand has negative effects on the grid. In this study, a flywheel storage system is used in order to reduce the peak demand caused by on-route fast-charging stations on the grid side. The proposed system has been analyzed and a 66% reduction in peak demand has been achieved.