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Why do transit agencies keep falling for the hydrogen bus myth?

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Re: Why do transit agencies keep falling for the hydrogen bus myth?

#21

Post by bobthepanda »

rsynnott wrote: post #18
bombcar wrote: post #14

Earlier quoted context omitted.

Batteries have won this so hard (if you ignore CNG busses, which have existed forever and are "almost as good as hydrogen could be") - because even when they hadn't won it, you just needed more busses. 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 n…

> But if it can't, you just design the route so that the driver can switch busses and buy another bus 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…

This depends a lot on local climate and topography.

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.

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#22

Post by cgh »

mitthrowaway2 wrote: post #13
WalterBright wrote: post #8

The electric airplane is another myth. There is no known battery technology, or one on the horizon, that can provide a large enough power/weight to make them practical. The investors are getting bilked.

They use electric seaplanes at Harbour Air for regional flights across the Georgia Strait between Vancouver, Seattle, and Victoria. Electric makes a lot of sense for short-range flights.

No, the eBeaver has never flown a commercial flight. Harbour Air is aiming for certification in 2026. Additionally, it only holds four passengers and is more a proof of concept than anything else. It is a cool effort but battery technology needs to come a long way first.

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#23

Post by 01HNNWZ0MV43FF »

Because people are allergic to hybrids and I don't know why

"Electric is short range, fuel is expensive, guess I have to pick one"

The ideal drivetrain was invented over 20 years ago by Toyota and apparently nobody but me and Honda noticed it!

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#25

Post by mschuster91 »

01HNNWZ0MV43FF wrote: post #23

Because people are allergic to hybrids and I don't know why "Electric is short range, fuel is expensive, guess I have to pick one" The ideal drivetrain was invented over 20 years ago by Toyota and apparently nobody but me and Honda noticed it!

> The ideal drivetrain was invented over 20 years ago by Toyota and apparently nobody but me and Honda noticed it!

The problem is hybrid drivetrains are complex. You don't save anything on the complexity of a combustion engine and exhaust train (over 1000 individual parts that have to be machined at extremely low tolerances), but add a more complex transmission (it needs to be able to work with two distinct inputs) and an electric drivetrain on top of that.

It is worth it in terms of energy efficiency and acceleration stats since even a small electric motor can supply a lot of torque at low speeds until the high-horsepower combustion engine catches up (virtually all modern cars have a turbocharger that needs time to spin up), but it's technically challenging to actually build into a modern car design - unlike 90s cars with ample space available to stuff components in, in a modern car every cubic centimeter is accounted for due to crash resistance.

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#26

Post by univacky »

cgh wrote: post #22
mitthrowaway2 wrote: post #13

Earlier quoted context omitted.

They use electric seaplanes at Harbour Air for regional flights across the Georgia Strait between Vancouver, Seattle, and Victoria. Electric makes a lot of sense for short-range flights.

No, the eBeaver has never flown a commercial flight. Harbour Air is aiming for certification in 2026. Additionally, it only holds four passengers and is more a proof of concept than anything else. It is a cool effort but battery technology needs to come a long way first.

Firstly: I'm a fan of Harbour Air's work and their electrification. Have flown that airline.

Retrofitting electrical flight to a 1950s airframe will be, in the long run, not a great use of the technology.

Those planes were designed around having a single heavy powerplant up front driving the propeller, and fuel largely distributed along the center of gravity (in the wings) so as not to adversely alter flight characteristics over the trip. The electrified Beaver stores its batteries in the fuselage; of course there is no change in mass/CG over the flight with electric, but all that fuel tank space in the wings is going to waste. The fact that these are floatplanes make charging/battery replacement tasks at the dock challenging and restrict options.

A clean sheet design, with multiple distributed smaller motors and more options for battery placement, will be a significant improvement.

https://harbourair.com/going-electric/?tab=Specification

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#27

Post by ZeroGravitas »

bombcar wrote: post #14
rsynnott wrote: post #6

Huh. I kind of thought that batteries had comprehensively won in this market, tbh. 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.

Batteries have won this so hard (if you ignore CNG busses, which have existed forever and are "almost as good as hydrogen could be") - because even when they hadn't won it, you just needed more busses. 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 n…

The stop-start nature of city busses makes them a real low hanging fruit for battery electrification, benefiting from instant torque to start and regen to stop and, as you say, fixed known routes within larger fleets.

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.

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#28

Post by mschuster91 »

WalterBright wrote: post #8

The electric airplane is another myth. There is no known battery technology, or one on the horizon, that can provide a large enough power/weight to make them practical. The investors are getting bilked.

> There is no known battery technology, or one on the horizon, that can provide a large enough power/weight to make them practical.

Small aircraft are already there. I'm looking into starting my pilots license this year, the local flight school recently acquired an Elektra Trainer [1], that apparently has 2.5 hours worth of flight time [2].

Big transoceanic widebodies obviously will be fossil fuel based for a long time to come, but I think a lot of the GA market and bush pilot/island hoppers can and will be done by electric planes sooner than later - alone because the noise and lead emissions are all but gone, and I think that in a few years, when experiences on failure modes are a bit richer, electric planes will also be cheaper to maintain - similar to cars, there are less parts involved in the first place that can break down.

[1] https://de.wikipedia.org/wiki/Elektra_Trainer

[2] https://www.br.de/nachrichten/bayern/elektrisch-fliegen-in-l...

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#29

Post by comte7092 »

Why do transit agencies keep falling for hydrogen busses? From the perspective of the US, it’s pretty simple:

1. Transit agencies have no way to reasonably validate what the future holds. From the standpoint of today, a hydrogen bus can be expected to replace a diesel bus 1 to 1, while battery electric is a 2 to 1 replacement. This might not be a huge issue except:

2. FTA regulations have strict requirements on how many spare busses may be kept at any time (defined by the ratio of peak vehicle usage vs the size of the overall fleet), doubling the size of the fleet blows this ratio out of the water.

3. It doesn’t matter what BYD offers or what’s possible in China, US transit agencies are required (FTA regs again!) to buy busses made in the US. American manufacturers do have somewhat decent battery electric products, but they are clearly not at the leading edge. With the proterra banktrupcy, there are limited competent suppliers in the market. To a large degree, gillig et al do get to decide what gets pushed into the market.

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#30

Post by xattt »

bombcar wrote: post #14
rsynnott wrote: post #6

Huh. I kind of thought that batteries had comprehensively won in this market, tbh. 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.

Batteries have won this so hard (if you ignore CNG busses, which have existed forever and are "almost as good as hydrogen could be") - because even when they hadn't won it, you just needed more busses. 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 n…

CNG buses were about a 10-year experiment in Toronto. There were a number of bus terminals where CNG vehicles were prohibited, either due to clearance or because of the associated explosion risk.

A second batch of buses were converted to diesel so that the fuelling station could be decommissioned.

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