This study develops a renewable energy-based system integrated with a flywheel-based storage system and presents a thermodynamic analysis for the renewable energy-driven and flywheel integrated fast-charging station for electric buses. This study has performed base on two sections, which are parametric and case studies. Solar and wind energies have been selected as the energy source. It is investigated that the effect of the flywheel integration as an energy storage solution on the decrease in the power requirement of the charging station. Case studies for Oshawa, Ontario, Canada and Kayseri, Turkey, have been conducted. At the end of the present study, it has been observed that flywheels have great potential to reduce power (load) capacity. The charging times of vehicle and flywheel have a significant effect on power capacity reduction. To increase the rate of power reduction, the charging time of flywheel should be as high as possible that vehicle charging duration. In order to reduce the energy losses in the flywheel, storing time should be minimized. While the energy efficiency for the solar-driven charging station is about 17%, for the wind-driven charging station is about 34%. In the case studies, while the flywheels have achieved to reduce by 60% of the power requirement of the system in Line 910 from Canada, they have decreased by 72% for Erciyes University Campus Ring from Turkey.