I still can't quite get used to the electric buses. A 20 tonne double-decker bus should sound like it might explode at any moment; it is unnatural for them to move around more or less silently.
Is it nice if the bus can do a driver's entire shift without a recharge? Sure! But if it can't, you just design the route so that the driver can switch busses and buy another bus. That means the technology problem is now a money problem.
Busses are also already quite heavy, so battery weight doesn't affect them as much as it might in a small car.
Oof, that's a huge 'just' in many cases.
That said, current electric buses have sufficient range that this mostly isn't an issue. The unnervingly silent double-deckers I mention have a claimed range of 320km, which, at least here, is sufficient.
The big problem with Dublin's electric buses, ridiculously, was that the operator was late in applying for planning permission for the substations required to charge them. With the result that for about a year, there were about a hundred of them stored and unusable.
Seattle has kind of been a bust with them because the hills really reduce the amount of charge, and on top of that the existing bus depots are already full, so switching to electric only would mean having to find and locate space for more bus depots, which is quite difficult.
Everything is cost, it's all cost, not the ability to actually solve the problem.
This is one of the great advantages of electric vehicles with batteries, when properly designed.
Electric buses with batteries are even more suitable for cities with hills than for cities without hills, because they provide greater energy savings over buses with ICEs.
While I have never used buses with batteries, I have lived in cities with electric trolley buses. Even with the primitive technology of many decades ago, they were doing great in cities with hills, recovering most of the energy when going downhill, unlike the buses with ICEs, which had excessive fuel consumption because of the hills.
You can just... do that, but that doesn't mean it's not a thing you have to do, and it's not free.
The efficiency of regenerative braking increases with the power of the vehicle. The electric efficiency should be well over 90%, perhaps even 95%. The mechanical losses will lower the total efficiency to much smaller values, but even so, the total efficiency should be over 80%.
A bus with an ICE will consume 5 times more extra energy for climbing the hill and it will also consume energy while going downhill.
Values like a 50% greater battery are unrealistic, and a heavier battery adds much less to the consumption than by how much it is heavier, even when going up the hill (because most of the extra energy consumption is also recovered).
In a certain city, it may happen that the bus routes are so long that batteries are not competitive with ICEs, at least for now. However, the presence of hills in any city can only make electric buses more advantageous, not less advantageous, due to much greater cost savings for fuel and maintenance. Buses with ICEs that are operated on hilly routes also need extra maintenance, besides increased fuel costs. Well-designed electric buses do not care whether they are operated in conditions requiring higher torque.
Like I have said, I have lived in cities with hills and with electric trolley buses and there was no doubt that the trolley buses were superior to buses with ICEs exactly on the routes that were going up and down over hills.
It's not just about conversion efficiency. Moving a vehicle up a hill requires several times as much power as traveling on level terrain, which heats the battery. Reaching the top of the hill and starting regen when going back down again, also heats the battery. On normal terrain that isn't all hills there will be level sections in between that allow the battery to cool. If the terrain doesn't have that then the battery gets too hot and the vehicle will disable regenerative braking and use friction braking to allow the battery to cool off. The steeper the hills are, the more heat is generated per unit time.
Batteries also have charge curves. In the extreme case you start at a higher elevation, go down a hill and can't use regen at all because the battery is full and there is nowhere to put it, but then you have to spend energy later to get back to where you started. The same is true even if the battery isn't fully charged, because extreme charge levels require charging to be done gradually and the battery might not be able to take as much power right now as a heavy bus would generate descending a steep grade.
> A bus with an ICE will consume 5 times more extra energy for climbing the hill and it will also consume energy while going downhill.
Modern engines will cut fuel entirely when descending a grade.
> the presence of hills in any city can only make electric buses more advantageous, not less advantageous, due to much greater cost savings for fuel and maintenance.
That doesn't contradict the point that they'll need to have larger batteries to achieve the same range on hilly terrain.
The original point was: hills do not matter, because what goes up must come down, and regen will get all the energy back.
This is categorically untrue, at the very least because regen doesn’t capture at 100% efficiency. It being “more than ICE” doesn’t mean anything.
Regen isn’t 100% efficient, for starters.
The other problem is that because battery weight is so large, that in itself becomes a limiting factor for hilly operation where it is not really relevant for trolleybuses. And trolleybuses can feed current from uphill buses to downhill buses through the wires, but there's no such connection on battery buses.
Is this deadpan sarcasm? Seattle isn't a mountain pass. The biggest hills are a couple hundred feet bottom to top. The "High Point" neighborhood, which is, uh, the highest point above sea level, is at 522 feet. Every other hill is smaller than that.
Total ascent time is measured in double-digit seconds, discounting lights/stop signs.
Alternatively, you could add charging infrastructure in more places. Eg, partially have trolley-like lines on the route to "top up". This could make sense on dedicated buslanes, especially when multiple lines use that stretch (eg near central stop).
The only nation that seems to have capitalised on this basic fact is China which bootstrapped its EV industry on busses, pulling ahead from 2010 and hitting 90% of global market share for EV busses in 2020, and now a big exporter.
A second batch of buses were converted to diesel so that the fuelling station could be decommissioned.
In short there are plenty of places to switch buses if you need to.
People through history have always considered about half an hour a reasonable daily commute. Doesn't matter if it is a hunter-gatherer going to their gathering grounds (if they follow herds they will move camp if the herd moves more than half an hour), or "modern man" going to the office, half an hour is what you get. Everything I said is based on making as many of those half hour trips possible as I can - but not all trips can be done that way and some locations will be left out.
Not only is that slower, having the first bus stop there and turn around instead of going all the way to B hasn't benefited anyone else either. The route from the first depot to the halfway point is still being covered by the same bus route. The interval is determined by how many buses cover that route and not just by its total length, and another bus that covers that section of the route might even go somewhere other than B after reaching the point you'd have had it turn around to go back, also giving a faster option than multiple transfers for people who want to go from A to C. When A, B and C are all high density areas, creating direct routes between them makes sense even if they're each more than 15 minutes apart.
This isn’t how bus routes work, and this isn’t how people ride busses, on most if not all of the…many PT systems I’ve used in multiple states / countries.
Imagine a metro area with somewhat grid-like streets (or at least common paths) that go on for an hour+ in each direction. People still generally cluster to 20-30min from the destinations they care to go to, so it doesn't break that standard. Breaking it up into four 15-minute stretches isn't making it better for anyone. All you're doing is forcing people to get off one bus at an edge and hop on another. Just run more busses on the full path so there's still ample service for the changes.
How does forcing the 15-minute max path make more destinations available?
You could also just have more lines even if they're long. The length of the lines doesn't change the number of them. It's just a question of how many busses and drivers do you really have and what service interval are you trying to hit.
If you're arguing they should have like a 15 minute hub and spoke model, you might also be forcing some really inefficient routes and once again force people to change busses more when one bus route could have better served the community.
The other aspect is the what city topology you are dealing with. In square grid cities, you can probably put a tram on every road, and with one switch over, get to where ever you need to get to.
But many organically grown cities end up using the hub-and-spoke model, where there are main stations where many different buses meet. People switch over to the next connection (and you need a buffer here). Critically, you need all the buses to meet at roughly the same clock time, say every 30 min. Now, one thing you realize immediately is that not all routes are equal. One route might be only 25 min, Either you make it longer and waste fuel, and time for everyone sitting on the bus, or you wait an extra 5 min at the main station.
Bus scheduling is very difficult problem in real cities with weird topologies and real traffic issues. Buffers are a necessary part of any reasonable solution.
(1) Better scheduling system. My opinion is that most real world systems are not too far away from the optimal trade-off curves. There is always room for improvements, or choosing better trade-offs, but it will rarely drastically improve things.
(2) More ridership: Most problems with speed just disappear if more people ride. For example, you do need a solid buffer when buses come every 30 min or more. But buses that come every 10 min or less, you can get rid of all buffer. A lot of scheduling problems are just not-enough-users problem.
Every workday I take a one-seat King County Metro bus ride that lasts about 1 hr. The bus starts at a layover facility and ends at a different layover facility.
I don’t see how this 15 minute interval maps to my actual commute?
This is such an odd insight. Most problems in the world can be described as a "money problem", and it's usually the problem that problem solvers are pushing up against.
Good article on this topic.
It's a lot of infrastructure investment but the per-mile running costs are so much lower that it should eventually pay off, especially as buses get cheaper when volume ramps up.
As someone who has witnessed EV buses in person, I think the local pollution and to a lesser extent noise benefits are really great for cities that have or want to move more toward human-friendly streetscapes. They just eliminate so much bus engine stench that just can't be good for breathing in.
It also seems to me that they have to be a lot more reliable. I have seen so many broken down buses with the engine compartment open on the side of the road in my lifetime.
And not even a horrible one. A bus that is driven half as much per day will wear out (about) half as fast. Which means, although you do have to buy twice as many buses up front, the number of buses you have to replace per year won't change.
So in the steady state, the cost of buses isn't actually that much worse.
There is still some penalty for needing more buses, though. For example, you have to pay more to store buses. Also some maintenance is more of a function of time than mileage driven. And you're tying up more capital, which may mean more bonds or opportunity costs.
In most of the US yes, in dense big cities they're still quite a bit worse (especially if they run at night too) because they're very noisy compared to electric or hydrogen.
I live in such a place where the buses were all CNG and are now shifting to electric. Unfortunately the switch isn't going too quickly, but every time an electric bus goes by the peace and quiet is blissful. I think every new bus they buy is electric, but I get that they don't want to throw out all of the existing CNG stock.
https://www.ithaca.com/news/ithaca/tcat-pulls-all-electric-b...
Established bus manufacturers make good electric buses now but we don't have the money to buy replacements.
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I hope you're using "should" as in "that's what I'm accustomed to" rather than "that's how it ought to be"... right? :-D
Personally I feel like quieting buses would be a huge step toward making day-to-day city life more pleasant.