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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

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 https://www.actransit.org/zebta

int0x29 2y ago
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
AtlasBarfed 2y ago
I'm not going to dispute your numbers with diesel versus EV reliability, but I have to think the simplicity of an EV drivetrain will win that battle in the next version or two.
- fraserharris 2y ago
  The reliability speaks to the technology immaturity. I agree with the inevitability of the EV drivetrain + charging off the existing distribution network being more reliable than competing technologies.
  - formerly_proven 2y ago
    idk these sound like very specific problems they had. The chargers had an availability of only 23% because of a recurring issue with the power modules failing. In a later volume they also again attribute a lot of unavailability to the same chargers: > The BEB fleet operated at 66% availability with more than half of the total days related to retrofit of the charger cabling and programming by the OEM. I guess you could say this is due to immature technology but honestly I don't see 75% of HPC chargers being offline for maintenance at any given time. This is probably just bad luck with a vendor. If you look at the road calls the BEB is by far the most reliable one, causing one road call out of 45. It was also the cheapest per mile by a long stretch.
- somat 2y ago
  Based on personal experience my guess is that the unreliability would be in the battery not the drive train. Or more precisely put, batteries are a sort of black box they ether work or they don't work but either way you are not going to be able to open one up and find out why. that is, they are a high cost unrepairable item on the vehicle and this is a huge liability.
  - BirdieNZ 2y ago
    Batteries aren't unrepairable; you wouldn't open one up in the middle of the road to try fix it but at the bus depot with enough volume of battery electric vehicles, they'll have reason to hire repair technicians that can refurbish and repair batteries.
    - AtlasBarfed 2y ago
      Obviously anything has a bunch of single points of failure, or catastrophic means of failure, but a battery isn't like "one engine". It's basically hundreds of little power modules wired in parallel, so an individual battery cell loss shouldn't bring down the whole pack. So a battery pack should actually be heavily redundant ... assuming the pack has enough modules for a loss of vehicle to get to some charging station.
- rco8786 2y ago
  It’s hard to imagine it not. And also kudos and crazy respect for all the thousands of engineers that poured their work into making combustion engines as efficient and reliable as they are. A true marvel of humanity, and something to be respected even as we leave it behind.
  - psd1 2y ago
    I see your point, but at best you're getting 40% thermal efficiency with IC. It's not great.
    - rco8786 2y ago
      Relative to EVs it’s not. But relative to ICE engines from 50 years ago it’s great. EVs are obviously going to take over ICE, my only point is that we shouldn’t discount all the work and ingenuity that went into ICE engines simply because a disruptive technology came about.
    - cbmuser 2y ago
      No one cares about thermal efficiency. What matters is the economic efficiency.
  - AtlasBarfed 2y ago
    And yet, how much earlier could we have had better solar panels and EVs? Certainly wind power was viable as soon as fiberglass was invented. The mass engineering should have also been directed at that which would have saved us a billion tons of carbon.
jeffbee 2y ago
They're much quieter however.
- beAbU 2y ago
  Limerick City in Ireland has electric double decker buses. They are dead quiet and it's a total treat to be a pedestrian without the buses passing by and blowing my ears off.
manquer 2y ago
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 given our on-off approach to hydrogen infrastructure[2] for both personal and commercial vehicles but there is some progress on commercial side at least last year [1]. Hydrogen is not everyone but there are use cases for it. The uptime (i.e. the refueling time) is an key factor [4]. Battery operated vehicles need a lot of downtime for charging thus you will need more vehicles for the same coverage. Fast charging can help but impacts battery life and thus TCO. All green public transit are expensive. It is not a easy choice for administrators, should they improve coverage/ service frequency etc for their residents who need transit the the most or better air quality and less noise pollution for all of them. Remember Fuel Cells are far cleaner for the air much more than BEV also, because it needs oxygen from the air FCs purify the air to do so. Kind of like having a big vacuum on the road in addition to not emitting direct pollutants[3] [1] https://www.portofoakland.com/port-of-oakland-celebrates-hydrogen-powered-trucks-project https://www.portofoakland.com/port-of-oakland-celebrates-hyd... [2] https://www.energy.ca.gov/data-reports/energy-almanac/zero-emission-vehicle-and-infrastructure-statistics-collection/hydrogen https://www.energy.ca.gov/data-reports/energy-almanac/zero-e... [3] Ignoring tire dust, it is problem for all vehicles of course, that is independent of propulsion systems [4] Even for personal vehicles it can be a decision factor when considering going green, as an owner of a Mirai with no easy access to EV charging stations I have benefited from being to refuel like a gar car.
- jandrese 2y ago
  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 noxious pollutants, less noise, lower maintenance, there is a lot to love.
rsynnott 2y ago
I note that their electric buses are made by a different company than their diesel buses, which would make reliability comparisons a bit questionable.
tim333 2y ago
I get the impression they've had similar results in London. They've had ~20 hydrogen busses for a while but apparently are expensive like £500k per bus plus you need to find hydrogen. On the other hand battery seems to be cracking along: "over 1,600 zero-emission buses currently in service, and TfL aims to have a fully zero-emission bus fleet by 2030, accelerating plans with increased government funding."

int0x29 2y ago

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

AtlasBarfed 2y ago

I'm not going to dispute your numbers with diesel versus EV reliability, but I have to think the simplicity of an EV drivetrain will win that battle in the next version or two.

fraserharris 2y ago
The reliability speaks to the technology immaturity. I agree with the inevitability of the EV drivetrain + charging off the existing distribution network being more reliable than competing technologies.
- formerly_proven 2y ago
  idk these sound like very specific problems they had. The chargers had an availability of only 23% because of a recurring issue with the power modules failing. In a later volume they also again attribute a lot of unavailability to the same chargers: > The BEB fleet operated at 66% availability with more than half of the total days related to retrofit of the charger cabling and programming by the OEM. I guess you could say this is due to immature technology but honestly I don't see 75% of HPC chargers being offline for maintenance at any given time. This is probably just bad luck with a vendor. If you look at the road calls the BEB is by far the most reliable one, causing one road call out of 45. It was also the cheapest per mile by a long stretch.
somat 2y ago
Based on personal experience my guess is that the unreliability would be in the battery not the drive train. Or more precisely put, batteries are a sort of black box they ether work or they don't work but either way you are not going to be able to open one up and find out why. that is, they are a high cost unrepairable item on the vehicle and this is a huge liability.
- BirdieNZ 2y ago
  Batteries aren't unrepairable; you wouldn't open one up in the middle of the road to try fix it but at the bus depot with enough volume of battery electric vehicles, they'll have reason to hire repair technicians that can refurbish and repair batteries.
  - AtlasBarfed 2y ago
    Obviously anything has a bunch of single points of failure, or catastrophic means of failure, but a battery isn't like "one engine". It's basically hundreds of little power modules wired in parallel, so an individual battery cell loss shouldn't bring down the whole pack. So a battery pack should actually be heavily redundant ... assuming the pack has enough modules for a loss of vehicle to get to some charging station.
rco8786 2y ago
It’s hard to imagine it not. And also kudos and crazy respect for all the thousands of engineers that poured their work into making combustion engines as efficient and reliable as they are. A true marvel of humanity, and something to be respected even as we leave it behind.
- psd1 2y ago
  I see your point, but at best you're getting 40% thermal efficiency with IC. It's not great.
  - rco8786 2y ago
    Relative to EVs it’s not. But relative to ICE engines from 50 years ago it’s great. EVs are obviously going to take over ICE, my only point is that we shouldn’t discount all the work and ingenuity that went into ICE engines simply because a disruptive technology came about.
  - cbmuser 2y ago
    No one cares about thermal efficiency. What matters is the economic efficiency.
- AtlasBarfed 2y ago
  And yet, how much earlier could we have had better solar panels and EVs? Certainly wind power was viable as soon as fiberglass was invented. The mass engineering should have also been directed at that which would have saved us a billion tons of carbon.

jeffbee 2y ago

They're much quieter however.

beAbU 2y ago
Limerick City in Ireland has electric double decker buses. They are dead quiet and it's a total treat to be a pedestrian without the buses passing by and blowing my ears off.

manquer 2y ago

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 given our on-off approach to hydrogen infrastructure[2] for both personal and commercial vehicles but there is some progress on commercial side at least last year [1]. Hydrogen is not everyone but there are use cases for it. The uptime (i.e. the refueling time) is an key factor [4]. Battery operated vehicles need a lot of downtime for charging thus you will need more vehicles for the same coverage. Fast charging can help but impacts battery life and thus TCO. All green public transit are expensive. It is not a easy choice for administrators, should they improve coverage/ service frequency etc for their residents who need transit the the most or better air quality and less noise pollution for all of them. Remember Fuel Cells are far cleaner for the air much more than BEV also, because it needs oxygen from the air FCs purify the air to do so. Kind of like having a big vacuum on the road in addition to not emitting direct pollutants[3] [1] https://www.portofoakland.com/port-of-oakland-celebrates-hydrogen-powered-trucks-project https://www.portofoakland.com/port-of-oakland-celebrates-hyd... [2] https://www.energy.ca.gov/data-reports/energy-almanac/zero-emission-vehicle-and-infrastructure-statistics-collection/hydrogen https://www.energy.ca.gov/data-reports/energy-almanac/zero-e... [3] Ignoring tire dust, it is problem for all vehicles of course, that is independent of propulsion systems [4] Even for personal vehicles it can be a decision factor when considering going green, as an owner of a Mirai with no easy access to EV charging stations I have benefited from being to refuel like a gar car.

jandrese 2y ago
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 noxious pollutants, less noise, lower maintenance, there is a lot to love.

rsynnott 2y ago

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

tim333 2y ago

I get the impression they've had similar results in London. They've had ~20 hydrogen busses for a while but apparently are expensive like £500k per bus plus you need to find hydrogen. On the other hand battery seems to be cracking along: "over 1,600 zero-emission buses currently in service, and TfL aims to have a fully zero-emission bus fleet by 2030, accelerating plans with increased government funding."