London buses spend a lot of time stopped at bus stops. I wonder if it would ever make sense to install a 500kW pantograph charger at each stop to give 3-4 minutes of top up.
In Zürich Switzerland the calculation was done between placing charging systems at end terminals or at the central garage (where busses park over night).
It was determined that a central garage charging setup is better because the time the bus spends at the end station may get shortened significantly in order to keep the bus on schedule. So charging time would be very irregular. Also to get the power infrastructure to those locations is very costly compared to a central location.
The new battery bus fleet in Zürich can run for about half a day and then return to the central garage.
Future buses are expected to become more efficient and have larger batteries so the central charging setup makes sense.
The central garage has a fast charging setup for 74 busses underground. It is a very impressive setup.
A lot of cars spend a lot of time stopped at traffic lights and often stopped/crawling in traffic, and it's probably why start-stop mechanisms can really improve fuel efficiency. Engineering Explained with "Americans Have No Idea How Much Fuel Idling Uses":
Even a 60kW unit [0] looks to be pretty large and listed as "call us for price".
[0] https://www.heliox-energy.com/us-products/60-kw-dc-charger
Might be a bit cheaper per unit if you buy 19,000 of them (one for each London bus stop).
I guess that's still less than half though.
London once had the world's largest system: https://en.wikipedia.org/wiki/Trolleybuses_in_London
They also experimented with a few electric buses and that also had range problems but much more importantly they realized if they had hundreds of buses charging overnight it would be a significant strain on the electricity system. Distributing the buses throughout the system and their charging in time by charging them at stops would be a solution to this.