[HN Gopher] Why do transit agencies keep falling for the hydroge...
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Why do transit agencies keep falling for the hydrogen bus myth?
Author : guerby
Score : 84 points
Date : 2025-03-14 15:03 UTC (7 hours ago)
(HTM) web link (cleantechnica.com)
(TXT) w3m dump (cleantechnica.com)
| guerby wrote:
| Linked also an interesting read :
| https://cleantechnica.com/2024/12/22/heat-pumps-for-electric...
| anenefan wrote:
| I have flagged for the 403 - Forbidden - at a site level.
| ZeroGravitas wrote:
| The obvious answer is that government incentives and policies are
| corrupted by fossil fuel interests.
|
| The article only makes this claim via a link to another article:
|
| > the Canadian Urban Transit Research and Innovation Consortium
| (CUTRIC), is riddled with conflicts of interest and bias toward
| hydrogen.
|
| In which they reveal gas pipeline companies and fuel cell
| manufacturers are members of that org and on its board.
| giantrobot wrote:
| The mechanism through which fossil fuel interests work is "grey
| hydrogen" which is hydrogen produced through processing of
| fossil sources with no eye towards carbon capture. Grey
| hydrogen is as polluting as just burning the fossil feedstock
| but works with an established hydrogen infrastructure.
|
| This lets the producers "green wash" their production pipeline
| by stating in a lies-through-omission manner that their
| hydrogen is "clean burning". See no carbon out of the tailpipe!
| It's clean! It's the same lie as EVs claiming to be "green" in
| places where fossil fuel sources dominate electricity
| production. It's just moving the tailpipe somewhere else rather
| than eliminating it entirely.
|
| There's also "blue" hydrogen that's manufactured with fossil
| fuels but claims/intends to capture the carbon produced in the
| process. It can still feed into a hydrogen infrastructure so
| fossil fuel companies love it due to the same greenwashing.
|
| The only carbon neutral hydrogen is "green" hydrogen which uses
| a renewable source and electrolysis of water to generate
| hydrogen. But even that is wildly less efficient on net than
| just using renewables to charge battery EVs. Electrons are far
| easier to move long distances than hydrogen or hydrogen
| feedstocks (including water).
| kaibee wrote:
| > It's the same lie as EVs claiming to be "green" in places
| where fossil fuel sources dominate electricity production.
|
| This is just anti-ev propaganda.
|
| First, its kind of a chicken-egg situation:
|
| 'its not worth going green for the power grid, all the cars
| are still ICE' 'oh its not worth building EV cars, the power
| grid is dirty anyway'.
|
| Second, there are lifecycle analyses that show that even if
| your powergrid is entirely fossil fuels, EVs are still a win.
| This is because powerplants are really efficient in ways that
| a car engine can't be because of scale/weight. iirc the only
| exception was if your power-grid was still like 50%+ coal?
| AnthonyMouse wrote:
| Not only that, it's completely the opposite: One of the
| biggest impediments to adding more renewables to the grid
| is aligning generation with load. EVs are rolling energy
| storage devices. Put EV chargers in workplaces with a
| setting that says "just make sure the battery has at least
| 100 miles of charge by quitting time" and you get a full
| 300 mile charge from 100% renewable energy whenever it's
| available, still enough to come back tomorrow if it's
| cloudy today, and a discount for using the charger where
| that's what happens.
|
| Then you not only charge the EVs from entirely renewable
| generation, most of them can curtail their load for about a
| week because typical EVs have around seven times the
| average commute in total range, and then when renewable
| generation is at 25% of normal, the capacity added to
| charge EVs can be directed to less flexible loads because
| the demand from EVs can be easily delayed for the right
| price.
|
| Their existence is what makes a grid with a higher
| percentage of renewables even work.
| genev wrote:
| Sadly my town of Santa Cruz is going through this right now:
| https://lookout.co/carmageddon-when-will-santa-cruz-metros-n...
| rsynnott wrote:
| 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.
| bombcar wrote:
| 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 now a money problem.
|
| Busses are also already quite heavy, so battery weight doesn't
| affect them as much as it might in a small car.
| rsynnott wrote:
| > 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 operator was late in applying for planning
| permission for the substations required to charge them. With
| the result that for about a year, there were about a hundred
| of them stored and unusable.
| bobthepanda wrote:
| 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.
| bombcar wrote:
| 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.
| KeplerBoy wrote:
| I wonder if trolley busses will make a great comeback
| now. Seems so obvious to just put the overhead lines near
| a few central bus hubs, so buses can recharge during the
| shift.
| adrian_b wrote:
| Hills should never reduce the range, because the energy
| lost during climbing up is recovered when going downhill.
|
| This is one of the great advantages of electric vehicles
| with batteries, when properly designed.
|
| Electric buses with batteries are even more suitable for
| cities with hills than for cities without hills, because
| they provide greater energy savings over buses with ICEs.
|
| While I have never used buses with batteries, I have
| lived in cities with electric trolley buses. Even with
| the primitive technology of many decades ago, they were
| doing great in cities with hills, recovering most of the
| energy when going downhill, unlike the buses with ICEs,
| which had excessive fuel consumption because of the
| hills.
| datadrivenangel wrote:
| Regenerative breaking is not perfectly efficient, so you
| may loose a significant portion of the additional energy
| needed. Better EV systems are what, 70-80% efficient on
| the breaking efficiency?
| kittoes wrote:
| Sure, but you lose 100% in the case of combustion...
| thfuran wrote:
| Okay, but gasoline is far more energy dense than
| batteries and a gas tank is a whole lot cheaper than a
| battery pack, so vehicles can have a gas tank big enough
| that that doesn't cause range problems. I don't know
| about buses, but you can buy a pickup with a 48 gallon
| tank. Even after assuming only about 1/3 efficiency,
| that's still equivalent to some 500 KWhr, which is
| several times more than any consumer EV I'm aware of.
| AnthonyMouse wrote:
| That's efficiency, not range. Suppose hilly terrain
| reduces range by a third for electric vehicles and half
| for diesel. The diesel bus just fills up twice as often.
| The electric bus needs a 50% bigger battery in order to
| finish the same route without stopping to charge, and
| then it becomes 70% because it has to lug the bigger
| battery up the hills.
|
| You can just... do that, but that doesn't mean it's not a
| thing you have to do, and it's not free.
| adrian_b wrote:
| It is impossible for a hilly terrain to reduce the range
| by a third for well-designed electric buses.
|
| The efficiency of regenerative braking increases with the
| power of the vehicle. The electric efficiency should be
| well over 90%, perhaps even 95%. The mechanical losses
| will lower the total efficiency to much smaller values,
| but even so, the total efficiency should be over 80%.
|
| A bus with an ICE will consume 5 times more extra energy
| for climbing the hill and it will also consume energy
| while going downhill.
|
| Values like a 50% greater battery are unrealistic, and a
| heavier battery adds much less to the consumption than by
| how much it is heavier, even when going up the hill
| (because most of the extra energy consumption is also
| recovered).
|
| In a certain city, it may happen that the bus routes are
| so long that batteries are not competitive with ICEs, at
| least for now. However, the presence of hills in any city
| can only make electric buses more advantageous, not less
| advantageous, due to much greater cost savings for fuel
| and maintenance. Buses with ICEs that are operated on
| hilly routes also need extra maintenance, besides
| increased fuel costs. Well-designed electric buses do not
| care whether they are operated in conditions requiring
| higher torque.
|
| Like I have said, I have lived in cities with hills and
| with electric trolley buses and there was no doubt that
| the trolley buses were superior to buses with ICEs
| exactly on the routes that were going up and down over
| hills.
| mike-the-mikado wrote:
| If the passengers all ride up hill and walk down hill?
| smolder wrote:
| Approximately 100% but not exactly, given that engine
| braking downhill drives the accessories without any fuel.
| (Alternator, aircon, pumps, etc.)
| bolognafairy wrote:
| Do you know which conversation you're replying to?
|
| The original point was: hills do not matter, because what
| goes up must come down, and regen will get all the energy
| back.
|
| This is categorically untrue, at the very least because
| regen doesn't capture at 100% efficiency. It being "more
| than ICE" doesn't mean anything.
| smolder wrote:
| Regenerative braking is nice but as sibling pointed out
| it doesn't nearly recapture everything. Another factor is
| that the additional load whether accelerating up a hill
| or braking down one puts more current through the system.
| In fact nearly every part of the drivetrain will
| experience accelerated wear under those conditions,
| mechanical or electrical. Cooling systems, too. Properly
| spec'd, it's of course very doable, but it's true hilly
| terrain is more difficult.
| bolognafairy wrote:
| This is a weird multi-paragraph evangelical lecture
| seeing as any EV owner that's driven in a hilly climate
| will tell you that this isn't how things work.
|
| Regen isn't 100% efficient, for starters.
| bobthepanda wrote:
| The problem is that the hills in Seattle are quite large,
| so you are going up for a long period of time and
| possibly not able to regenerate before you run out of
| batteries.
|
| The other problem is that because battery weight is so
| large, that in itself becomes a limiting factor for hilly
| operation where it is not really relevant for
| trolleybuses. And trolleybuses can feed current from
| uphill buses to downhill buses through the wires, but
| there's no such connection on battery buses.
| nindalf wrote:
| My grandparents live near those hills. The funny thing
| is, they're uphill both ways.
| potato3732842 wrote:
| I think it depends more on the regulatory climate.
| ZeroGravitas wrote:
| 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.
| busthrowaway23 wrote:
| (At least in King County Metro) the newer diesel-electric
| buses are series hybrids that use electric motors for
| traction, and diesel generators to power a small battery.
| So the low hanging fruit of electric traction was already
| "picked". You can look up the bus model online - New Flyer
| XDE class
| AnthonyMouse wrote:
| For the same reason the electric mail trucks are a good
| idea. You can probably expect UPS and FedEx to start
| replacing their fleets over time as the existing vehicles
| age out, now that all electric vans are starting to become
| available.
| xattt wrote:
| 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.
| abdullahkhalids wrote:
| Many bus routes have a 5-10ish min break at some point
| (usually the main station) in the route. If you can utilize
| those ten minutes to do a top-up, you can go a lot further on
| the same sized battery.
| bluGill wrote:
| No bus route should be more than 15 minutes between full
| and empty. That is you start at some station, go 15
| minutes, then turn around and go back. There are many
| systems that attempt to do more, but there is no point:
| people have places to be: on the bus is not on that list.
| That 15 minutes means an average of 7 minutes, now they
| walk to some other express bus that gets them nonstop (at
| faster speeds) to someplace, but you still only get 15
| minutes to get there before it isn't worth the bother, than
| 7 more minutes on some other bus. Add in 5 more minutes of
| walking time (and transfer time!) and we are at 45 minutes
| - this is unreasonably long for normal trips already, but
| it is the best you can do!.
|
| In short there are plenty of places to switch buses if you
| need to.
| thfuran wrote:
| Is there any bus route anywhere that never goes more than
| 15 minutes from the depot?
| bluGill wrote:
| Not that I know of - but there shouldn't be.
| AnthonyMouse wrote:
| How do you get somewhere which is 20 minutes from the
| depot, or in general between any two points that are more
| than 15 minutes apart?
| bluGill wrote:
| You put in a different depot for the 20 minute trip. With
| express buses the trip between the two depots may only be
| 5 minutes.
|
| People through history have always considered about half
| an hour a reasonable daily commute. Doesn't matter if it
| is a hunter-gatherer going to their gathering grounds (if
| they follow herds they will move camp if the herd moves
| more than half an hour), or "modern man" going to the
| office, half an hour is what you get. Everything I said
| is based on making as many of those half hour trips
| possible as I can - but not all trips can be done that
| way and some locations will be left out.
| bolognafairy wrote:
| Sorry, but, what the hell? This is Hacker News at its
| finest: completely talking out of its ass.
|
| This isn't how bus routes work, and this isn't how people
| ride busses, on most if not all of the...many PT systems
| I've used in multiple states / countries.
| bluGill wrote:
| There is a reason people complain about buses and prefer
| to drive in so many cases. Operators try to compromise on
| cheap and end up with service for those who after 5 DWIs
| can't get their friends to drive them anymore.
| busthrowaway23 wrote:
| This is highly regional - any major city with a decent
| transit system will have excellent bus routes in dense
| areas. Also, "operators" usually means bus drivers, not
| transit agencies
| abdullahkhalids wrote:
| There are two critical aspects to the bus routing
| problem. One is that no matter how well you design your
| system, there is always variance in the arrival times of
| a bus at any given stop. If you expect people to switch
| buses, then you need to account for this variance, and
| this means adding buffers. Nothing makes people stop
| using buses faster than missing your connection because
| your bus was late.
|
| The other aspect is the what city topology you are
| dealing with. In square grid cities, you can probably put
| a tram on every road, and with one switch over, get to
| where ever you need to get to.
|
| But many organically grown cities end up using the hub-
| and-spoke model, where there are main stations where many
| different buses meet. People switch over to the next
| connection (and you need a buffer here). Critically, you
| need all the buses to meet at roughly the same clock
| time, say every 30 min. Now, one thing you realize
| immediately is that not all routes are equal. One route
| might be only 25 min, Either you make it longer and waste
| fuel, and time for everyone sitting on the bus, or you
| wait an extra 5 min at the main station.
|
| Bus scheduling is very difficult problem in real cities
| with weird topologies and real traffic issues. Buffers
| are a necessary part of any reasonable solution.
| bluGill wrote:
| I'm coming from a different perspective: regardless of
| all else (all those issues you raised are very real),
| people need to get where they are going in a reasonable
| amount of time. Most bus service fails to account for
| that, but if you can't get people there in a reasonable
| amount of time there is no point in trying.
| abdullahkhalids wrote:
| I agree that a system that does not deliver is going to
| fail. Transit systems can have improved scheduling in two
| ways:
|
| (1) Better scheduling system. My opinion is that most
| real world systems are not too far away from the optimal
| trade-off curves. There is always room for improvements,
| or choosing better trade-offs, but it will rarely
| drastically improve things.
|
| (2) More ridership: Most problems with speed just
| disappear if more people ride. For example, you do need a
| solid buffer when buses come every 30 min or more. But
| buses that come every 10 min or less, you can get rid of
| all buffer. A lot of scheduling problems are just not-
| enough-users problem.
| busthrowaway23 wrote:
| Am I misunderstanding you about the 15 minutes interval?
|
| Every workday I take a one-seat King County Metro bus
| ride that lasts about 1 hr. The bus starts at a layover
| facility and ends at a different layover facility.
|
| I don't see how this 15 minute interval maps to my actual
| commute?
| zizee wrote:
| > That means the technology problem is now a money problem.
|
| This is such an odd insight. Most problems in the world can
| be described as a "money problem", and it's usually the
| problem that problem solvers are pushing up against.
| PaulHoule wrote:
| In Tompkins County we were early adopters of the electric bus,
| at least for the American market. We bought them from a startup
| which had trouble with the structural aspects and eventually
| they fell apart
|
| https://www.ithaca.com/news/ithaca/tcat-pulls-all-electric-b...
|
| Established bus manufacturers make good electric buses now but
| we don't have the money to buy replacements.
| ttttannenbaum wrote:
| Five months before the company filed for bankruptcy,
| Proterra's CEO was appointed to the President's Export
| Council (PEC), "the principal national advisory committee on
| international trade."
| Tijdreiziger wrote:
| > 451: Unavailable due to legal reasons
|
| > We recognize you are attempting to access this website from
| a country belonging to the European Economic Area (EEA)
| including the EU which enforces the General Data Protection
| Regulation (GDPR) and therefore access cannot be granted at
| this time.
| jrussino wrote:
| > 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.
| jpm_sd wrote:
| Transit agencies don't have the technical expertise to
| distinguish truth from lies in cleantech marketing. They aren't
| the only ones, see the over-inflated valuations of both Nikola
| and Tesla as two (very different) stories of companies
| successfully lying to investors and the general public about the
| magical capabilities of their novel transportation platforms.
| WalterBright wrote:
| 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.
| titzer wrote:
| > to make them practical.
|
| ..practical to replace commercial airliners, sure. There have
| been plenty of slow electric planes.
|
| In the future, net-zero air travel can only be done by
| producing jet fuel in a carbon neutral way.
| myself248 wrote:
| They're great for trainers. Short hops with immediate control,
| low maintenance and operating cost, and you can save the
| magneto/ignition/etc workload for a different lesson series.
| WalterBright wrote:
| I can see that. Although managing the engine is a major part
| of learning to fly.
| marcosdumay wrote:
| So, make electric airplanes the initial license, reduce the
| amount of hours to get it, and have an entire course on
| monomotors before pilots can deal with combustion
| airplanes.
| thijson wrote:
| I thought they might make sense for trainer aircraft that
| flight schools would use.
| thijson wrote:
| Also saw this:
|
| https://harbourair.com/going-electric/?tab=Specification
| mitthrowaway2 wrote:
| 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.
| cgh wrote:
| 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.
| univacky wrote:
| 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
| WalterBright wrote:
| 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.
| gorgoiler wrote:
| 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!
| HPsquared wrote:
| 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.
| WalterBright wrote:
| 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.
| HPsquared wrote:
| Being constrained to a ship makes things harder though.
| If it was simply very long (runway length), I reckon an
| abort would be fine. There are probably a lot of
| different ways to do it.
|
| But yeah, much harder than a regular runway. Probably not
| economical.
| onlyrealcuzzo wrote:
| You're assuming these investors actually believe it, and not
| that they can sell it to a greater fool.
|
| VC will invest in snake oil if they think they'll get out at a
| profit.
| mschuster91 wrote:
| > 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...
| WalterBright wrote:
| It appears to be an ultra-light.
| mschuster91 wrote:
| It is, because it's easier to get started with
| certification and experience in ultralights than in full-
| size planes. It won't be long until we see bush capable
| Cessnas, I think.
| xnx wrote:
| > The electric airplane is another myth.
|
| Strong disagree. Short range eVTOL craft will blow open the
| market for all kinds of use cases.
| WalterBright wrote:
| I've heard that story for 40 years. Invest in it if you like.
| I'll pass.
| mystified5016 wrote:
| The plane, of course, flies anyway becuase planes don't care
| what humans think is impossible
|
| /j
| gamegoblin wrote:
| Beta Technologies is already shuttling cargo between
| bases/depots for the US military with their eVTOL aircraft.
|
| Demonstrated range of over 300 nautical miles. Significantly
| higher reliability than helicopters previously used for the
| same task, and much cheaper.
| jillesvangurp wrote:
| Really? The Beta Alia CX300 just completed a coast to coast
| journey (Vermont - Santa Monica). Range of about 338 miles
| using 200kwh of completely unremarkable ~150wh/kg batteries.
| With 500wh/kg batteries being announced from multiple
| manufacturers now, that range should improve pretty quickly.
|
| > There is no known battery technology, or one on the horizon,
|
| The planes and batteries are getting there.
| avidiax wrote:
| I feel there is an unaddressed market for a hybrid gas/electric
| or diesel/electric powerplant.
|
| Size the battery for takeoff/climbing/go-around/diversion use-
| cases. Size the fossil-fuel engine for cruising power, which
| should improve efficiency. During takeoff and climbing power,
| the two motors work together. During cruise and descent, the
| electric motor regenerates the battery. I imagine that for
| general aviation, you would maintain one propshaft and not even
| bother with a clutch pack, since the gas engine is needed in
| all phases of flight, and freewheeling an electric motor is
| simple. Perhaps have the fossil-fuel engine keyed to the shaft
| with a shearing pin, so that if the engine seizes, the electric
| motor still turns the prop.
|
| This has the advantage that you now have two independent
| motors, which could eventually help with ETOPS rating, but
| would initially improve safety/reliability for general
| aviation.
|
| Yes, you are still fossil-fuel dependent, but you burn much
| less of it, first by offsetting some takeoff energy to the
| electrical grid, and secondly by reducing reserve power in the
| fossil fuel engine to improve efficiency.
| 01HNNWZ0MV43FF wrote:
| 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!
| mschuster91 wrote:
| > 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.
| jshier wrote:
| 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?
| wahern wrote:
| This was the GM Volt, predecessor to the Bolt:
| https://en.wikipedia.org/wiki/Chevrolet_Volt GM ceased
| production in 2019. The answer to your question can
| probably be found there, but IIRC [from GM's perspective]
| the consumer market preferred ICE + battery over electric +
| generator, especially after the all-electric options came
| to market and siphoned demand from the latter.
| BerislavLopac wrote:
| BMW i3 and Chevrolet Volt both had that option:
| https://en.wikipedia.org/wiki/Range_extender
|
| And of course, there are plug-in hybrids:
| https://en.wikipedia.org/wiki/Plug-in_hybrid
| jfengel wrote:
| It just turns out not to be worth it. The generator is a
| lot of weight to add, and a whole bunch of new parts to
| maintain.
|
| It's a lot easier to add enough batteries to match the
| range of an ICE car. Range anxiety is largely manufactured
| at this point. The cars know how far they can go and where
| the chargers are. A gasoline powered generator would be a
| huge extra cost with no real upside other than averting a
| non-problem.
| 00N8 wrote:
| Edison Motors is working on a system like this. They're
| looking to sell kits for retrofitting it onto pickup
| trucks, & a larger scale semi truck cab version for use
| with logging trucks. It looks great in their videos,
| although I'm not sure if they're selling to the public yet
| - probably a ways to go before it's really mass produced.
| AnthonyMouse wrote:
| That is called a series hybrid and the reason they're not
| popular is that the power split device in common hybrids is
| simply better.
|
| The power split device isn't an ordinary transmission, it's
| a set of planetary gears with a fixed gear ratio between
| three shafts. One goes to the wheels, the other two to the
| engine and the electric motor respectively. The ratio of
| the engine speed to the wheel speed is then set by the
| speed of the electric motor connected to the third shaft,
| which gives you a CVT with no belts, clutches, torque
| converters or even synchros.
|
| The transmission is "more complicated" only in the sense
| that it contains electric motors. In every other respect
| it's simpler, more efficient and _more reliable_ than an
| ordinary transmission. Meanwhile those electric motors mean
| you don 't need a starter motor or an alternator because
| the engine can be started by the electric motor through the
| transmission and an electric motor is a generator when
| operated in reverse.
|
| A series hybrid still requires you to have a gas engine
| with all that entails, but now the gas engine needs its own
| dedicated electric generator/motor _and_ you can 't deliver
| power from the gas engine directly to the wheels, so the
| traction motors have to be bigger in order to supply 100%
| of the torque used in acceleration instead of the gas
| engine and electric motors both contributing. That makes
| series hybrids heavier, slower and more expensive, so
| they're basically useless. Probably the main advantage
| would be that you could offer the generator as an option on
| what would otherwise be a full electric vehicle and then
| only people who need the extra range would pay for it.
| MostlyStable wrote:
| Wouldn't an additional advantage of series hybrids be
| that the engine can be tuned to operate solely in it's
| most efficient RPM band, since it just charging the
| battery and doesn't need to deal with changing speeds?
| This can (according to some _very_ cursory googling),
| result in efficiency gains of 20-30% relative to the
| least efficient RPMs. This should at least partially
| offset some of the size and weight considerations, since
| you don 't need to size the engine for it's energy output
| in less efficient speeds. This seems like it would be
| most important in stop-and-go conditions where the engine
| is spending considerable time at less efficient speeds,
| such as in a bus.
| AnthonyMouse wrote:
| The parallel hybrids can already do that because of the
| CVT.
|
| They also allow the engine to run at higher speeds under
| heavy acceleration because the peak efficiency RPM and
| the peak power RPM are different and the assumption is
| that if the driver is stomping on the accelerator they
| want to resolve the power/efficiency trade off in favor
| of power right now.
| torginus wrote:
| Most BYD PHEVs work like that - with the additional option
| of connecting the engine directly to the wheels via a
| clutch at highway speeds. I think Honda has a similar
| system.
| xnx wrote:
| Some hybrid drivetrains have fewer moving parts than a
| traditional ICE and are more reliable.
| wahern wrote:
| That undersells it. The data on hybrid drivetrains is
| pretty clear--it's definitely more reliable. Even mechanics
| will tell you that; certainly mine did, and he's not a
| masochist. Start+stop is hell on mechanical drivetrains.
| It's a no-brainer when purchasing a new car _except_ that
| there 's still a premium for hybrid, so the RoI might not
| be there given baseline reliability and depending on your
| preferences. Though the premium gap is closing, at least
| for non-plugin hybrids. Plugin hybrids are the new premium
| option in model lineups, so traditional hybrids are moving
| down market.
| bluGill wrote:
| My plugin hybrid (I just bought it 2 weeks ago) is on
| track to save me $200/month over the others similar
| vehicle it replaced (minivan with the same engine, but 10
| years difference in years, so lots of other differences).
| Tade0 wrote:
| My ROI is in how I can slam in reverse when I'm rolling
| forward or floor it whenever without concern for the
| drivetrain.
| vardump wrote:
| Sounds counterintuitive.
|
| Any references?
| floxy wrote:
| https://www.rav4world.com/threads/how-the-ecvt-operates-
| with...
| em500 wrote:
| At least for Toyota hybrids, the intuition is that the
| traditional ICE transmission system is replaced by what
| Toyota calls a "power split device" which continuously
| feeds and balances the electric and combustion power
| sources. This power split device uses a simpler gearing
| system (enabled by the high torque electric motors) and
| appears to be mechanically simpler and more reliable than
| traditional transmission systems (which probably wear out
| quicker than the engine in most ICEs).
| bell-cot wrote:
| Here in SE Michigan, one local transit authority ditched its
| new hybrid busses and returned to diesel ~15 years ago -
| because the TCO for the hybrid busses was so much higher that
| fixing the hole in their budget proved impossible.
| a1o wrote:
| What is TCO?
| bigthymer wrote:
| Total Cost of Ownership
| astura wrote:
| Total Cost of Ownership.
|
| It includes fuel & upkeep costs.
| busthrowaway23 wrote:
| (At least in King County Metro) their newer diesel-electric
| buses are series hybrids that use electric motors for traction,
| and diesel generators to power a small battery. The drivetrain
| seems smart but maybe other agencies use it less? You can look
| up the bus model online - New Flyer XDE class
| Tade0 wrote:
| I've ridden both hybrid and electric buses and I prefer the
| latter, as those huge engines still produce a lot of vibration.
|
| I drive a Toyota hybrid and while it's a step up from a purely
| combustion propelled car, I still have to do oil changes and
| its fumes still smell bad when it's running rich for whatever
| reason.
| AnthonyMouse wrote:
| The drivetrain was actually invented several decades before
| that. It wasn't until around 20 years ago that the _batteries_
| got to the point to make it practical to use.
|
| They're also made by more than Toyota and Honda. The American
| automakers have been offering vehicles with a similar hybrid
| powertrain for around two decades and the German automakers for
| only a little less than that. But they're generally not a
| separate _model_ like the Prius is, so the only exterior
| difference is a hybrid badge on what is otherwise visually
| identical to the non-hybrid car /truck of the same model.
| comte7092 wrote:
| 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.
| xnx wrote:
| > 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
| cf100clunk wrote:
| 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.
| gwbas1c wrote:
| A local airport shuttle service converted some of their vans to
| propane. They told me the benefit is that they go about 3-4x
| longer between oil changes. (I suspect they aren't brave enough
| to go 500,000 miles.)
| bolognafairy wrote:
| I tell you hwat!
| ianburrell wrote:
| There isn't any point to propane now. Electric busses got good
| enough to do the job. Propane reduces pollution, but the goal
| is to reduce CO2 emissions. Buying propane means buying
| electric in decade or two.
| javiramos wrote:
| Please also electrify garbage trucks
| drdirk wrote:
| Here in Barcelona Spain they are electric!
| hatthew wrote:
| > Fuel cell buses do produce sufficient waste heat, but here's
| the problem: it's exceptionally expensive heat. Every degree of
| warmth comes from hydrogen -- a fuel that's costly to produce,
| store, and transport. Unlike diesel, heating with hydrogen's
| waste heat is technically easy but economically painful.
|
| Isn't waste heat pretty much free by definition?
| hannob wrote:
| Within one technology, that'd be true. But not if you have the
| option to choose another technology that produces a lot less
| waste heat.
| hatthew wrote:
| Yeah, I just find the framing very weird. It's talked about
| as if it's somehow worse than diesel. But then isn't the
| issue that hydrogen fuel is less economical than diesel in
| general, regardless of whether the fuel is used for
| locomotion or for passenger heating? In the context of
| passenger heating specifically, waste heat is either free for
| both diesel and hydrogen, or equally non-free for both.
|
| Also the article appears to be arguing for electric instead
| of hydrogen buses, but for some reason seems to try to frame
| "winter range" as being an issue for hydrogen buses
| specifically, and then says "electric buses face a different
| challenge" -- winter range.
|
| I feel like there are two separate points that can be made:
|
| - Hydrogen fuel is more costly than diesel or electric (not
| even sure how true this is, but it's what the article seems
| to indirectly imply).
|
| - Hydrogen fuel doesn't have winter range issues the way
| electric buses do, but regardless electric is still better
| for other reasons.
| kstrauser wrote:
| Thanks, you beat me to it. While it _is_ more expensive per
| watt, that 's a sunk cost: you've already paid it when you were
| consuming the hydrogen to make the bus move.
| egypturnash wrote:
| Opening image: ChatGPT.
|
| I'm just gonna assume the rest of the article is from the same
| source and close this tab.
| jillesvangurp wrote:
| That goes for anything hydrogen and wheels pretty much.
|
| It's actually pretty simple to figure out. Making hydrogen takes
| energy. You lose some of the energy making the hydrogen. This is
| not a fixable problem. At least not unless you break the laws of
| thermodynamics.
|
| When you have created hydrogen, you lose more energy compressing
| the energy. Then you have to transport it to wherever it's going
| to be pumped into the vehicle ... both of which take more energy.
| Then it goes into a fuel cell, which loses more energy. All these
| losses multiply. And if you know your maths, you know that
| multiplying numbers smaller than 1 means the result gets smaller
| and smaller. These losses are significant.
|
| And we're comparing it with putting the energy into a battery
| directly. It has inherently better round trip energy. Even if
| hydrolyzers, and the infrastructure to store, compress, and
| transport hydrogen were free (which they are not), using hydrogen
| would still be more expensive than that. Because it wastes more
| of the energy that goes in. So, in addition to the energy losses,
| you also need to deal with infrastructure cost. On top of regular
| energy infrastructure.
|
| Anyway, that's all theory. For practice, just look at market
| price of hydrogen. Most of that stuff is of the dirty grey
| hydrogen variety creating that wastes a lot of methane. So much,
| that it would be cleaner to just use the hydrogen in a combustion
| engine in the bus and you'd have less CO2 emissions. Expending
| more methane to make hydrogen to have less emissions makes no
| logical sense.
|
| If you are using grey hydrogen, it is more expensive per mile
| than methane. Nothing can change that. If you are using green
| hydrogen, it is more expensive per mile than battery electric.
| Nothing can change that either. That's just physics and simple
| economics. Yes there are some innovations in this space happening
| that reduce the gap a little. But it's never going to be enough.
|
| Right now it's not even close. Unless somebody is subsidizing the
| hydrogen fuel, you'd be paying way more per mile than with
| diesel. And not just a little bit. And a common reason to switch
| from diesel to BEV is that it actually costs way less per mile
| than diesel. So, instead of saving money, you are spending more
| money.
|
| Subsidies are hiding the true cost of hydrogen. That's the only
| reason there are some vehicles on the road. As soon as the
| subsidies dry up, hydrogen transport use cases evaporate. There
| are of course plenty of other use cases where hydrogen is needed
| that make much more economical sense. Using scarce and expensive
| hydrogen for transport is a poor use of resources. The utopian
| world where we have vast amounts of hydrogen surpluses does not
| exist.
| aagd wrote:
| Also this: https://en.wikipedia.org/wiki/Trolleybus
| andix wrote:
| Trolleybusses are surprisingly expensive to operate. Battery
| electric busses seem to be much cheaper to operate and often
| good enough.
| tim333 wrote:
| There are some hydrogen busses working in the UK.
|
| >34-bus expansion, jointly funded by Brighton & Hove Buses and
| Surrey County Council, bringing their total hydrogen fleet to 54
| vehicles - the largest hydrogen bus operation in the UK.
| https://drivinghydrogen.com/2025/02/04/hydrogen-buses-34-new...
|
| I'm not sure how cost effective it is compared to battery though.
| andix wrote:
| Answer to the question: political reasons and lobbying.
|
| Hydrogen is produced by the big oil and gas companies. By pushing
| hydrogen vehicle instead of battery electric vehicles they stay
| in business.
|
| They market hydrogen as a green alternative to oil, although most
| hydrogen is currently produced from fossil sources, and this
| won't change soon (next 10 years).
| m463 wrote:
| that site never loads for me - 403 forbidden
| manchego wrote:
| I'm just waiting for flywheel powered buses to make a return:
| https://en.m.wikipedia.org/wiki/Gyrobus
| Ericson2314 wrote:
| Cool :) but reminds me that all energy storage is scary and an
| accident waiting to happen.
|
| Flows > stocks, overhead wire for the win!
| NikkiA wrote:
| I personally think Battery buses with SAE J3105 'docking'
| points at key stops (basically, the stops that are used to
| loiter to set timing, rather than leaving as soon as
| possible) is a better solution than the cost of stringing OHL
| through every major road in a city.
|
| https://en.m.wikipedia.org/wiki/Battery_electric_bus#Chargin.
| ..
|
| https://en.m.wikipedia.org/wiki/SAE_J3105
| askvictor wrote:
| I'm currently reading "The Windup Girl" set in a mostly-post-
| fossil-fuel future, where most energy storage is springs.
| why_at wrote:
| Wow I had no idea this existed
|
| >Disadvantages
|
| >Weight: a bus which can carry 20 persons and has a range of 2
| km (1.2 mi) requires a flywheel weighing about 3 tons.
|
| >The flywheel, which turns at 3000 revolutions per minute,
| requires special attachment and security--because the external
| speed of the disk is 900 km/h (560 mph).
|
| It's truly a mystery why they never caught on
| adamanonymous wrote:
| You missed the last and most funny one
|
| >Driving a gyrobus has the added complexity that the flywheel
| acts as a gyroscope that will resist changes in orientation,
| for example when a bus tilts while making a turn, assuming
| that the flywheel has a horizontal rotation axis.
|
| So you have a giant blender than can travel one mile in a
| straight line before needing to be recharged
| calibas wrote:
| Back in 2003, President George W. Bush announced the Hydrogen
| Fuel Initiative. At the time, people criticized the effort as an
| attempt by the oil industry to shift attention away from electric
| cars. The oil industry knew that hydrogen power wasn't going to
| be viable anytime soon, while electric cars were already a direct
| threat to their profits, so they pushed the US government towards
| hydrogen power.
|
| Not to disparage the talented scientists and engineers working on
| hydrogen power, but now that 20 years have passed I believe it
| was designed to fail.
| yummypaint wrote:
| It absolutely was. In the event that breakthroughs happened and
| it became viable faster than expected, the backup plan was to
| get the hydrogen from fossil fuels to make sure the industry
| would still get its cut.
| analog31 wrote:
| Isn't that the only plan right now? Is commercially viable
| hydrogen being made from any process other than the shift
| reaction?
| yummypaint wrote:
| Back when the Bush admin was hyping this stuff they managed
| to get the media to talk mostly about electrolysis of water
| using solar power. They would talk about how only water
| comes out the tailpipe, and the symmetry of being able to
| reuse water to make more fuel was extremely appealing to
| the credulous minds of the public.
|
| Nothing has really changed either, 20 years later and
| laypeople still don't have better information about this
| technology...
| ninalanyon wrote:
| Because the US is in thrall to the oil companies.
| fraserharris wrote:
| 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 than Diesel.
|
| The results are broken down into 4 volumes, each covering 6
| months. You can read them here: https://www.actransit.org/zebta
| int0x29 wrote:
| Only two years? They operated hydrogen buses from 2006 to 2010
| and then got some more in 2011 and 2019. There are budget line
| items for new buses in 2023 and 2024 that I assume got bought
| gblargg wrote:
| https://archive.is/G6I98 (for those not wanting to enable
| JavaScript)
| neves wrote:
| 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 benefit. By diverting badly needed clean power, green
| hydrogen vanity projects may even slow down the energy
| transition. And the subsidy regimes that are being put in place
| could become self-perpetuating. As Gernot Wagner and Danny
| Cullenward recently warned, "hydrogen could become the next corn
| ethanol", a ruinously inefficient and environmentally damaging
| creature of subsidies that are too big to kill.
| askvictor wrote:
| Not just to delay, but they're hope is that they'll be able to
| control it when it happens. Oil companies move fluids, using
| pipes and tankers. Hydrogen is a fluid. They want to keep doing
| what they've been doing. Electricity doesn't fit into their
| M.O.
| pjscott wrote:
| Do you have actual knowledge of their motives? Or is this
| speculation, confidently stated as fact?
|
| Another possible motive, mentioned in the the paragraph you
| quote, is that the oil companies see an energy transition
| coming and are trying to get aboard the hydrogen train to
| diversify their future revenue sources. And that sounds like a
| reasonable motive; the sort of thing that people who don't see
| themselves as evil villains - i.e. the supermajority of people
| - could embrace.
| londons_explore wrote:
| If hydrogen busses really were going to have a lower operational
| cost per mile in 2050, then some company would be offering to
| lease busses for $X per mile to transit operators, fuel included,
| for a 25 year lease. They'd make a loss initially, but big
| profits later.
|
| That approach turns this technology maturation and cost risk into
| a market, and those with most expertise can then put their own
| money on the line to help everyone make the right decision.
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