The application of regenerative braking energy for water electrolysis is discussed in this work. Fuel savings can be achieved by using the hydrogen produced by this method to offset the quantity of hydrogen fuel required. Hydrogen can also be produced by reusing the by-product water. In addition to conserving fuel, the extra weight of the vehicle due to the by-product water is also greatly decreased. The amount of time spent using the brakes is the primary factor that determines how much hydrogen fuel is consumed during a journey. Significant braking reduces the quantity of hydrogen fuel utilized. The greatest reduction in hydrogen fuel use from the seven typical driving test cycles is 21.33%. When the driver of the SUT campus bus service stepped on the brakes, it was pretty hard. This enables the reproduction of hydrogen using braking energy, resulting in a 46.61% reduction in the amount of hydrogen used.