Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

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

cleantechnica.com

Post reply on HN
Print view View original

31–40 of 503 posts

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

#31

Post by bombcar »

bobthepanda wrote: post #21
rsynnott wrote: post #18

Earlier quoted context omitted.

> 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.

Seattle also has (or had) trolley busses which fixed that problem.

Everything is cost, it's all cost, not the ability to actually solve the problem.

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

#32

Post by jshier »

mschuster91 wrote: post #25
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)…

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?

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

#33

Post by xnx »

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…

> US transit agencies are required (FTA regs again!) to buy busses made in the US

BYD makes electric buses in California: https://en.wikipedia.org/wiki/BYD_K_series

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

#34

Post by xnx »

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.

> The electric airplane is another myth.

Strong disagree. Short range eVTOL craft will blow open the market for all kinds of use cases.

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

#35

Post by xnx »

mschuster91 wrote: post #25
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)…

Some hybrid drivetrains have fewer moving parts than a traditional ICE and are more reliable.

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

#36

Post by WalterBright »

univacky wrote: post #26
cgh wrote: post #22

Earlier quoted context omitted.

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 characte…

Storing the weight in the wings significantly reduces the stress in the wings over storing it in the fuselage.

Makes me wonder about their design tradeoffs.

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

#37

Post by WalterBright »

HPsquared wrote: post #20
gorgoiler wrote: post #16

Earlier quoted context omitted.

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!

The risk assessments are a teeny bit different. Edit: although maybe there's a good idea: catapult or winch launch for electric aircraft would massively reduce the power and energy storage requirements to be carried onboard.

Look at all the effort that goes into launching an airplane with a catapult on an aircraft carrier.

There are other issues - like you cannot abort a catapult in progress.

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

#38

Post by WalterBright »

xnx wrote: post #34
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.

> The electric airplane is another myth. Strong disagree. Short range eVTOL craft will blow open the market for all kinds of use cases.

I've heard that story for 40 years. Invest in it if you like. I'll pass.

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

#39

Post by cf100clunk »

Look into propane (a.k.a. LPG or Autogas).

If the goal is anything-but-diesel-or-gasoline/petrol, the use of propane (a fossil fuel that is a byproduct of oil and gas refining) is a well-understood, well-implemented practice. I am not advocating for propane as a primary solution, but rather as part of the journey towards truly clean vehicle emissions and the ramp-down of heavily polluting fossil fuel refining. Propane and the equipment to operate engines with it are available today, and we have the knowledge going back over a century to implement it successfully.

BTW, I wish I could find the article from the 1970s discussing how Ford Motor Company engineers had converted a brand-new 1960s Lincoln to propane and ran it with 100% synthetic motor oil, never changing the oil or filter. After 500,000 miles of daily use, they stripped the engine down to its parts and found it to be shiny and not exhibiting the expected amount of wear seen in usual engines of those years with much lower mileage. I'd have to pour through old magazines for that story, but life gets in the way, so let's treat my recollection as apocryphal.

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

#40

Post by WalterBright »

mschuster91 wrote: post #28
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 ti…

It appears to be an ultra-light.
Post reply on HN