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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?

#491

Post by numpad0 »

VBprogrammer wrote: post #273
numpad0 wrote: post #265

Earlier quoted context omitted.

Hydrogen vehicles are EVs too. They don't run H2 through a piston engine, it goes through a catalytic converter that generates electricity, aka Fuel Cell. Toyota FC stack costs ~$11k, about the same if not cheaper than a 100kWh worth of Li-ion cells.

And the number of hydrogen powered vehicles sold year on year is currently decreasing. As are the number of places to fill them up in the UK at least.

Because only Toyota makes them and mostly for publicity, yes. But my points are 1) hydrogen cars are pure EVs too, just not lithium, and 2) hydrogen primary battery thing isn't that expensive, or finicky for that matter.

I'm not like a hydrogen believer, I just loathe incorrect technical understandings on the Internet, like any techy person would.

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

#492

Post by GuB-42 »

gorgoiler wrote: post #16
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.

Silly idea, but if the power is needed for takeoff then the aircraft could be plugged in with a cable up until it reaches cruising altitude. It sounds ridiculous but I’ve been in aircraft that take off while attached to a cable thousands of feet in length — a winch launched glider!

Considering how thick fast charging cables for cars are, I don't think it will fly, literally. We could make the cables thinner with high enough voltage I guess. But then we would actually need two wires with proper separation, because unlike with trains, you obviously can't use the ground for the return path. Loose high voltage wires may be a safety problem too.

By comparison glider launch wires are quite thin and light.

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

#493

Post by D_Alex »

thaumasiotes wrote: post #490
D_Alex wrote: post #489

Earlier quoted context omitted.

"Molar" refers to a number of elementary entities, which could be atoms or molecules or w/e. So yes, if you are counting moles of H2 gas, but not if you are counting atoms...

But hydrogen gas is the only thing you can get from that reaction. There is a theoretical construct of monatomic hydrogen, also a gas, but you're guaranteed to get molecular hydrogen instead. And there will only be 40 moles of it. There isn't a way for you to end up with 80 moles of hydrogen product.

Ooh, I love pedantry contests!

Let's go back to your opening comment which was something like "I thought methane was 80% hydrogen on a molar basis". Methane does not contain H2 molecules, it contains 4 atoms of hydrogen. Plus one atom of carbon, which would indeed make it 80% hydrogen on a molar basis.

If that does not convince you: note also that atomic carbon is also a very unstable, and will auto polymerize into one of its allotropes (eg. C60 - buckyballs). And yet we count carbon by the atom.

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

#494

Post by cjbenedikt »

AlexandrB wrote: post #373
MayeulC wrote: post #312

Earlier quoted context omitted.

These are common terms. A random link: https://www.weforum.org/stories/2021/07/clean-energy-green-h... * Green: produced from surplus renewable capacity (electrolysis) * Black, brown, grey: convert various fossil fuels to hydrogen via steam reforming. Basically strip carbon from hydrocarbons, emitting a lot of CO2. * Blue: same as black/brown/Greg but with carbon capture. There are other (less common) shades as well.

And Green is a huge efficiency loss. I suppose if the energy used to do it truly "green" and "surplus"... > As of 2022, commercial electrolysis requires around 53 kWh of electricity to produce one kg of hydrogen, which holds 39.4 kWh (HHV) of energy. https://en.m.wikipedia.org/wiki/Electrolysis_of_water

Frequently the green energy used to split water is "surplus" energy. For example the bulk of offshore wind energy happens between 10pm and 2am when energy demand is at its lowest. That energy goes to waste if not stored in hydrogen. Hence, efficiency is irrelevant.

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

#495

Post by frollogaston »

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?

I know people have already said that PHEVs do this, but the other comments made it seem more niche than it really is... About 35% of EVs are like this: https://en.wikipedia.org/wiki/Plug-in_hybrid#/media/File:Rat...

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

#496

Post by frollogaston »

Beijinger wrote: post #397

This is propaganda. I can find you a dozen websites and statements from University professors, why gas, electricity or hydrogen is doomed from the beginning. And I can find another dozen, why they are the future. "stuck with 19 buses that they have to drive a long way to refuel at great overall expense, something I wrote about this week." This seems like a problem that can be solved, but it is a hen and egg problem.…

This isn't comparable to the EV charging station problem, because at least there's already electricity everywhere and you don't need to convert to hydrogen on top of that.

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

#497

Post by culi »

adamsb6 wrote: post #426
culi wrote: post #416

Earlier quoted context omitted.

Tesla succeeded because heavy and intense government subsidies and investment into making electric cars a thing The fact that an EV failed without that kind of publicly funded support is only evidence that furthers the point GP was making

They succeeded where others failed because they are fun to drive. There were no fun EVs prior to the Roadster. And the Roadster was a small production precursor to Model S, which transitioned from boutique-ish to mass production, and which led to the Model 3, and then the Model Y, the number one selling car in the world. Until the past five years or so almost every other EV was still an oddball whose design language…

No they succeeded because of carbon credits. To this day, 42% of Tesla's revenue is just carbon credits.

That means that everyone who is buying a gas guzzler is helping fund Tesla. Tesla was one of the first to have an EV-only lineup which means they could sell 100% of their carbon credits. Every company that wants to sell a gas guzzler has to pay Tesla for carbon credits in order to do so

Also the massive government bailouts and subsidies helped ofc https://subsidytracker.goodjobsfirst.org/parent/tesla-inc

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

#498

Post by culi »

chrisco255 wrote: post #441
culi wrote: post #416

Earlier quoted context omitted.

Tesla succeeded because heavy and intense government subsidies and investment into making electric cars a thing The fact that an EV failed without that kind of publicly funded support is only evidence that furthers the point GP was making

Tesla succeeded because it focused on the luxury market first by building the Roadster (and then later the model S). It succeeded because they showed that electric cars can be cool and not associated with lame-looking and performing Priuses and Leafs. It succeeded because people bought billions of laptops and cell phones powered by lithium ion batteries, which finally produced the economies of scale and had the right…

It succeeded because it was the only company to only sell EVs. That means everyone who wants to buy a gas guzzler is funding Tesla. In the past decade, over 40% of all of Tesla's revenue is carbon credits

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

#500

Post by hulitu »

neves wrote: post #125

Why? Because Oil Companies are lobbying for inefficient hydrogen to delay a green revolution: https://adamtooze.substack.com/p/carbon-notes-5-green-hydrog... > The members of the hydrogen coalition are all obviously incumbent fossil fuel and petrochemical interests looking for a bridge to the new era. If realized, their ambitious hydrogen projects may overload the available supply of green power, for little real bene…

> delay a green revolution:

Batteries are pretty messy for the environment. And carrying a ton (1000 kg) with your car, just to be able to move, is a bit too much.

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