Lowest short term maintenence cost. Until the battery is destroyed in a couple of years.
Charging a fleet of 100 buses overnight looks like a huge infrastructure issue to me. 100 charging ports, huge grid connection, substation etc. That is if the local grid even has capacity. Anyone who has tried to open a factory will know that is not always the case.
EV batteries have been performing much better than dying after just 700 cycles. Also, power is generally cheapest overnight when there is excess grid capacity. People with variable electricity pricing and battery banks make money by charging overnight and releasing power to the grid during peak hours. Commercial vehicles typically get more like 6,000 cycles out of a battery pack.
Charging a fleet of 100 buses overnight looks like a huge infrastructure issue to me. 100 charging ports, huge grid connection, substation etc. That is if the local grid even has capacity. Anyone who has tried to open a factory will know that is not always the case.