We see a lot of marketing blah nowadays about electric buses, much of it being driven by marketing coming out of China which is accepted uncritically by many of the newbies to electrification in the industry. We don't see much comparative study that should be mandatory when approaching new technology. This work is normally done in Europe which, of course, has had well over a century of experience with electric transit, but that is typically ignored outside Europe as being "outdated", with the trolley bus being a particular laughing stock among the ignorant.
We do have a basic picture that the WOL cost of a battery electric bus is similar to that of a diesel bus, but it's not so publicised that a battery electric bus costs a lot more upfront (though much cheaper to maintain), has a restricted passenger capacity because of its weight, has significant downtime and needs a battery bank renewal at eye-watering cost around half-life of the bus, thus also shortening the life of the bus because it's uneconomic to replace the batteries a second time late in the life of the bus.
We rarely see this quantified, because it doesn't suit the marketing agenda of the battery-electric bus proponents, but recently a Czech manufacturer of electric drive equipment, Cegelec, has released a short paper comparing the relative costs of battery-electric (overnight charge), battery-electric (opportunity charge) and trolley (in-motion charge) buses.
https://www.cegelec.cz/wp-content/uploa ... ity-EN.pdf
Particularly interesting is the bar chart which contains the sort of information that the authorities in Wellington and Brisbane, for example, should have properly considered before they made the decisions they did. If the process had been followed properly, Wellington should still have trolleybuses and Brisbane should have built a trolleybus system for the fixed routes traversed by its double articulated buses. (The Hess bus model that they're buying actually has a trolleybus version as well.)
Of course, it's difficult to convince a city to build a system with overhead wires from scratch, but some cities like Prague and Berlin are because they have a power supply already in place from their tram systems and, with the modern dynamic charging trolleybus, the whole of a route doesn't need to be wired any longer.
Some of these issues have been identified here by the private sector, through BusNSW, which has addressed two significant issues for battery-electric buses operated in Australia.
https://www.parliament.nsw.gov.au/ladoc ... BusNSW.pdf
1. The standard operating life of a battery-electric bus needs to be reduced to 18 years because of the cost of battery replacements (which represent about 20-30% of the cost of the bus, as shown also in the chart in the Cegelec paper). There will be one half-life replacement, but the cost of a second replacement close to full-life (presently 25 years) is uneconomic. (This is barely an issue for a modern in-motion charging trolleybus.)
2. The loss of passenger capacity in a battery-electric bus is substantial (typically some 20 passengers) due to weight and the need to comply with axle load standards. Hence there's a need for agreement on some sort of exemption to the national heavy vehicle standards to enable battery-electric buses to carry similar loads to diesel buses (or to the lighter trolleybuses for that matter). This loss of capacity is quite a serious problem, economically, because it means that additional buses (and drivers) have to be acquired to move the same number of passengers as previously.
My main reason for posting all of this information is that the issues are not as clear cut or black and white as is often made out. There are no clear answers as to which option is better - all have pluses and minuses, though the dynamic-charging trolleybus does have the lead on several counts, but may not be acceptable to many jurisdictions. The only thing that's certain is that the diesel city bus is down and out on environmental grounds. I won't comment on fuel cell buses because there is too much that is unresolved at this stage.