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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?

#241

Post by rsynnott »

KeplerBoy wrote: post #148
jrussino wrote: post #131

Earlier quoted context omitted.

> A 20 tonne double-decker bus should sound like it might explode at any moment 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.

Busses are not going to be quiet. Around here we have pretty cool "Van Hool ExquiCity" trolley busses and they can glide gracefully at slow speeds, but when they are hurtling down patched up streets they are not much quieter than the traditional busses.

Most city buses spend most of their time going fairly slowly. The electric buses are absolutely a lot quieter, at least around here. Crucially, also, they don’t vibrate; I’ve never been on a diesel bus where vibration from the engine wasn’t at least somewhat noticeable.

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

#242

Post by masklinn »

newuser94303 wrote: post #234
andrepd wrote: post #207

Earlier quoted context omitted.

Plenty of this in Europe. In my country there's less km of rail now than there was in 1910.

which country?

Pretty much all of them. At least in the west, less sure about the east.

France had 70000km of rail around ww1, now it has about 30000. The main (though not only) casualty was the rural narrow gauge lines ("local interest network") which got obliterated by car and low productivity (about 20000km progressively closed from about 1930 to 1960, a handful survive as tourist attractions).

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

#243

Post by rsynnott »

fraserharris wrote: post #119

AC Transit (eg: East San Francisco Bay) performed a detailed 2 year study (July 2020 - June 2022) comparing newer Hydrogen Fuel Cell & Battery -powered buses to existing Diesel, Fuel Cell, & Hybrid -powered buses, 5 of each type. The key results are the Hydrogen Fuel Cells have significantly more expensive infrastructure, fuel, and maintenance costs than Battery. However, both technologies are still less reliable tha…

I note that their electric buses are made by a different company than their diesel buses, which would make reliability comparisons a bit questionable.

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

#244

Post by zejn »

Guthur wrote: post #240
Retric wrote: post #221

Earlier quoted context omitted.

Hydrogen is also a byproduct of some source of energy, it doesn’t just materialize. The difference is batteries are vastly more efficient at storage and doing useful work with that stored energy. There’s use cases where that’s fine like rocketry, but efficiency or energy density is usually a dealbreaker.

What the hell are you talking about, a. batteries weren't mentioned and b. hydrogen is on the periodic table and exists as an element, and can actually be found in its pure form.

While hydrogen can be found in its pure form, the reserves are not really developed.

Hydrogen is generally considered a storage, not a resource. Same as battery.

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

#245

Post by rsynnott »

comte7092 wrote: post #29

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 m…

> With the proterra banktrupcy, there are limited competent suppliers in the market.

Do the conventional bus manufacturers in the US not make electric buses? All of the electric buses here are made by the transport authority’s traditional manufacturers.

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

#246

Post by masklinn »

jandrese wrote: post #202
manquer wrote: post #191

Earlier quoted context omitted.

The maintenance costs are only marginally higher per the report at $1.33 FCEB vs $1.15 BEB , $2.37 for Hybrids and $1.28 for Diesel (with additional public health costs for respiratory illnesses), the sample size(5x5) is too small to draw any meaningful conclusion on infrastructure costs or even reliability given the limited experience in operating anything not diesel. Economics of hydrogen in CA are also complicated…

If I'm reading that right the Battery Electric busses had the lowest maintenance costs? The need to charge is a potential issue, but at the same time busses do lots of low speed stop and go where battery systems are most efficient. As long as the bus has enough capacity for an entire day and can be recharged overnight it seems like an ideal solution, minus of course the up-front cost of the bus. Lower fuel costs, no…

An other option BEV busses give is hybrid trolleys, that way once a popular line gets fixed you can add overhead lines to it and later upgrade it to tram more easily.

It also means charge is a matter of having overhead lines which can be added as hoc (as overhead docking stations) to end-of-line stops, letting the bus juice up for some time before it runs the route back.

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

#247

Post by thaumasiotes »

genev wrote: post #5

Sadly my town of Santa Cruz is going through this right now: https://lookout.co/carmageddon-when-will-santa-cruz-metros-n...

Geez.

> Metro gets about one or two buses every week or so, and that it typically takes around four months of testing before they are put into service. The lengthy testing process is necessary because the Volkswagen Environmental Mitigation Trust, one of the funders of the Metro’s initiative, requires the agency to destroy one of its existing buses before putting a new one on the road

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

#248

Post by rsynnott »

Ericson2314 wrote: post #122
manchego wrote: post #107

I'm just waiting for flywheel powered buses to make a return: https://en.m.wikipedia.org/wiki/Gyrobus

Cool :) but reminds me that all energy storage is scary and an accident waiting to happen. Flows > stocks, overhead wire for the win!

Think that’s bad? Look at this thing! https://www.en-former.com/en/mammoth-flywheel-for-irelands-g...

4GJ of stored energy, dischargeable in eight seconds.

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

#249

Post by rsynnott »

jshier wrote: post #32
mschuster91 wrote: post #25

Earlier quoted context omitted.

> 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)…

As a simple driver of cars, I've never understood why no one has mass produced an EV with a built-in generator. That would avoid the complexity of the hybrid drive train, allow easy plugin and short range electric-only travel, and could even be offered as an optional attachment. So what am I missing? Is the efficiency gained by the generator offset by losses through the EV system?

The BMW i3 had this as an option; I don’t think it was a particularly popular option.
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