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

cleantechnica.com

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

#301

Post by jimnotgym »

Tade0 wrote: post #285
jimnotgym wrote: post #266

Earlier quoted context omitted.

> Fuel cells are presumably more expensive than battery packs. Maybe, but a tank of hydrogen burnt through an ICE is much cheaper than either For your storage and production concerns, here it is working in practice https://youtu.be/5rk1RsT64o4?si=LLmX51kT2_YeRp2g

> Maybe, but a tank of hydrogen burnt through an ICE is much cheaper than either It's really not. Most of the hydrogen bus projects were killed by the surprising cost of fueling - approximately 4x the cost of electricity. And no wonder: just the energy wasted producing hydrogen and then using it in a fuel cell is enough to build a battery pack that will last the equivalent.

Is that the cost of the fuel itself, or the high cost of providing it in a world with little infrastructure?

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

#302

Post by VBprogrammer »

jimnotgym wrote: post #296
defrost wrote: post #288

Earlier quoted context omitted.

The greatest tonnages are dug out with bench mining excavators. These work 24/7/365 round the clock to fill trucks from bench faces and empty into trains. An area such as the Pilbara region moves a billion tonne of raw material a year and ships most of that. These excavators are electric with cables that drag behind them .. they move very slowly across bench faces and then move back across the face again, it's not li…

Very interesting, but it is a niche specific case that doesn't answer the question at all. Imagine a tractor in a field. What is the solution for that?

I don't think a tractor is necessary a bad use case for batteries. They just need battery packs which can do the equivalent of a days work. Electric motors are almost better suited to the use case due to the torque. I'm sure some of the US mega farms have tractors which run all night (and the emissions of those are the least of their environmental issues) but this isn't common elsewhere.

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

#303

Post by olau »

jimnotgym wrote: post #292

How much power does it take to charge a bus in a reasonable amount of time? I heard 100kw. If I have 100 buses charging overnight at 100kw I guess I need 10Mw grid connection? Is that an easy thing to get to a city bus depot in the US. In the UK I believe that would require moving to a location with a HV line and building a sub-station.

If you charge the buses over night, then you don't need 100 kW. I think the battery sizes are something like 100-300 kWh. So with 9 hours of charging, you need only perhaps 30 kW at the most.

Anecdotally, the town I live in invested in probably around 100 buses. They did build a new depot with charging stations.

Batteries are coming down in price, so if getting a good grid connection is a problem, you can put in a buffering battery.

The comfort of the BEV buses is much better than the old diesel buses, by the way, and they are much less noisy in the city.

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

#304

Post by ajb »

D_Alex wrote: post #293
jasonkester wrote: post #284

Earlier quoted context omitted.

Can you define your hydrogen colors for us? It sounds like you have something interesting to say, but I can’t parse what it is out of your company’s jargon.

"Blue hydrogen" is commonly used for hydrogen produced from natural gas. If it is produced by steam reforming (most common), then the associated CO2 emissions are worse than if you just burn the natural gas directly. "Green hydrogen" is usually hydrogen produced from water by electrolysis, using electricity from non-CO2 source, e.g. wind or electricity.

Blue hydrogen is supposed to capture the carbon. If its just emitted, then it's grey hydrogen: https://www.nationalgrid.com/stories/energy-explained/hydrog...

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

#305

Post by D_Alex »

jimnotgym wrote: post #292

How much power does it take to charge a bus in a reasonable amount of time? I heard 100kw. If I have 100 buses charging overnight at 100kw I guess I need 10Mw grid connection? Is that an easy thing to get to a city bus depot in the US. In the UK I believe that would require moving to a location with a HV line and building a sub-station.

No, that is not right. The correct answer is "it depends", but let's run some indicative numbers on data for Boston:

On average and excluding the minority of routes with dedicated lanes (which may be best run on diesel), the Boston metro buses are in use for 6.6 hours per day, covering on average 53 miles.

A full size electric bus uses electricity at a rate of approx 2 kWhr/mile.

So, on average the bus would have around 17 hours to charge up with 106 kWhrs of juice, and this averages out to about 6.2 kW. On average.

However, the smart thing to do would be to charge the buses when the power costs the least, say between 10 pm and 8 am, so you'd need ~10 kW/bus, maybe ~1MW for the 100 bus fleet. Not difficult.

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

#306

Post by im3w1l »

tonyhart7 wrote: post #216
tonyhart7 wrote: post #215

Earlier quoted context omitted.

" Because Oil Companies are lobbying for inefficient hydrogen to delay a green revolution" well NO, contrary to popular belief. there is no such things because 1. Oil is scarce resource that not every country have 2. since not every country has, they must import it with expensive trade deficit meaning that Oil alternative or replacement is very much needed since country like china,south korea and japan that has massi…

that's why china is leading an EV revolution, government seeing that as very much important geopolitic and economic wise if hydrogen is feasible in mass scale, trust me someone in Asia would already make it

Toyota bet big on hydrogen.

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

#307

Post by fifilura »

ZeroGravitas wrote: post #290
fifilura wrote: post #236

I am surprised there is no mention of CNG/biogas buses. They are very common here in Sweden. The engine is more or less the same as a gasoline/diesel engine. The biogas can be (and is) locally produced by food/farming waste or similar but can also run on fossile gas. And for the buses it is no problem to carry the somewhat bulky cylinders on the roof.

There's also biofuels. In Norway until recently the biofuel mixing requiremnts were doing as much to avoid CO2 in passenger cars as EVs, though EVs grew so they're about twice as effective now. Still a powerful complementary strategy. https://robbieandrew.github.io/EV/img/avoided_emissions.svg

The mix the Swedish populist government removed for lower gas prices.

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

#308

Post by VBprogrammer »

alvah wrote: post #252
semi-extrinsic wrote: post #235

Earlier quoted context omitted.

Oil pipelines, no. Gas pipelines, yes. The effort to requalify existing gas pipelines for hydrogen use is well underway in Europe. There might be a need to run at lower pressure, depending on the type of steel, but leaks are not an issue.

Hydrogen embrittlement is a massive issue, I’d be interested to hear how this can be engineered around. My understanding is it requires more exotic materials than those used in any existing NG or oil pipelines. Everything I’ve seen claiming it’s viable to use existing infrastructure seems reasonable at first glance, but invariably contains a massive hand-wave or 2.

I think the obfuscation is that they are generally talking about stuffing small quantities of hydrogen into natural gas pipelines. Similar to alcohol in gasoline.

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

#309

Post by jimnotgym »

olau wrote: post #303
jimnotgym wrote: post #292

How much power does it take to charge a bus in a reasonable amount of time? I heard 100kw. If I have 100 buses charging overnight at 100kw I guess I need 10Mw grid connection? Is that an easy thing to get to a city bus depot in the US. In the UK I believe that would require moving to a location with a HV line and building a sub-station.

If you charge the buses over night, then you don't need 100 kW. I think the battery sizes are something like 100-300 kWh. So with 9 hours of charging, you need only perhaps 30 kW at the most. Anecdotally, the town I live in invested in probably around 100 buses. They did build a new depot with charging stations. Batteries are coming down in price, so if getting a good grid connection is a problem, you can put in a bu…

Ok so you still need 3MW or with a buffering battery as big as your fleet you could spend half the day charging the batteries. So you still need what, 1.5MW? Or is it half that. It is still a grid connection that is larger than you could easily find in an old inner city bus depot, I would have thought?

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

#310

Post by VBprogrammer »

im3w1l wrote: post #306
tonyhart7 wrote: post #216

Earlier quoted context omitted.

that's why china is leading an EV revolution, government seeing that as very much important geopolitic and economic wise if hydrogen is feasible in mass scale, trust me someone in Asia would already make it

Toyota bet big on hydrogen.

Bet in the past tense? It seems they are moving further away from that position. There are also some domestic market issues for Toyota - Japan having the lowest voltage mains electricity in the world for example.
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