7 ms·

Caltrain's electric fleet more efficient than expected

340 points by ssuds 2y ago

skrap 2y ago
I mean, this is good news, but why was the efficiency of the system so misunderstood at the design phase? I hope someone's interested enough to find out!
- crocal 2y ago
  Ahoi! Participated to the development of a simulation tool for that purpose. Many factors need to be taken into account: - The gradients of the track - How agressively you want to drive at different time of the day - How many trains - The timing of the trains. When one train brakes, it can power another one that accelerates at the same moment - The efficiency of the power chain - The resistance model of the train With so many parameters the results can be quite volatile. However, rule of the thumb in the business is that 30% saving can be achieved with good energy management. Hope this clarifies a little. Update: bullet points
  - skrap 2y ago
    Interesting! Thanks for the great info. Do you know if anyone will have the opportunity to integrate observations into the model so it can continue to improve?
    - crocal 2y ago
      We did use actual data from existing lines to measure the gap between our models and reality. We were +/- 5% accurate.
- djaychela 2y ago
  Maybe they didn't factor in ridership on certain part of the track gradient, which would lead to more regen braking than expected?
jeffbee 2y ago
It's hilarious but sad to watch Americans learn things that agencies abroad already know. The other example of this I saw today was that in NYC the congestion pricing has "surprisingly" slashed the number of car crashes and injuries in Manhattan. Like, duh.
- readdit 2y ago
  I feel this is positive news moving in a positive direction. Do you suggest not doing anything to improve the situation? We can’t go back in time. But we can help ourselves in the future.
  - ninetyninenine 2y ago
    I feel this improvement is negligible. I doubt you'll see any meaningful change in your lifetime. At best you'll see an electric car renaissance. But the infra for trains and public transit? Doubtful.
    - readdit 2y ago
      It’s still a positive change an I’m all for it.
      - ninetyninenine 2y ago
        I'm all for positive change too. But as someone who isn't delusional, I have to account for practicality rather then dreaming about an unrealistic future.
  - dhosek 2y ago
    I think it’s more that Americans seem to be surprised by things that people in other countries have known for decades. Meanwhile, the current administration is trying to send us back to the 19th century in civil rights, healthcare and energy policy.
    - 2y ago
blintz 2y ago
The electric Caltrain is so wonderful. It’s way quieter, the cars have nicer interiors, and it is running faster and more frequently than before. Between this, the new BART cars (also much quieter!), and Muni hitting a reliability & satisfaction records, there’s really a transit renaissance going on in the Bay Area. I really hope we can keep this going!
- ninetyninenine 2y ago
  Haha. Doubtful. In your lifetime you won't see any transit system in the bay area that approaches anything remotely close to what you see in places like Tokyo or NYC. I get that there's improvement but like it's still rather pathetic compared to almost everywhere else across the pond.
  - lswainemoore 2y ago
    Why so negative? Given that the served population is conservatively a quarter of either of those areas, doesn't seem like a fair comparison. More to the point, I've been favorably impressed with the transit options since moving here, and in terms of reliability it's been better than NYC, though obviously there are fewer trains/branches. I'd love to see BART open later, like NYC, but even Tokyo trains stop at midnight.
    - astrange 2y ago
      NYC is more or less the only system in the world that runs all night like that. It makes it very hard to do maintenance.
      - frosted-flakes 2y ago
        And NYC can do that because most of it's lines have three or four tracks.
    - ninetyninenine 2y ago
      It's fair. NYC is 8.8 million, bay area is 7 million. Tokyo is about double that. Not being negative. Being realistic. It's unfortunate that being realistic often is negative. Transit here is garbage. You either luck out and live and work near transit or you're like most people and have to drive. A couple million in energy savings doesn't mean anything compared to the amount wasted by cars.
zer0zzz 2y ago
Finally some good news
deleted 2y ago
[deleted]
two_handfuls 2y ago
Another cool thing in the article that I didn't know personally: Caltrain runs on 100% renewable power!
- benatkin 2y ago
  That shouldn't be put forth as a goal. It's how Germany got rid of all its nuclear plants and has to keep burning coal and buying fuel from Russia.
  - blamazon 2y ago
    It's also how Scotland ended up harnessing their wind power, much to the consternation of one American capitalist...
whyenot 2y ago
It's great, but it took more than 20 years to get here due to environmental reviews and shaky funding. ...and this was just re-fitting an existing, relatively short stretch of track! We (as Californians) have GOT to do better than this! There are huge infrastructure projects that we need to undertake in the coming years. We have got to cut the red tape and properly fund projects.
- sunday_serif 2y ago
  Completely agree! The hard parts seems to be figuring out (1) how to cut red tape for only certain projects and (2) figuring out what red tape to keep. Chesterton's fence and all that.
  - thereisnospork 2y ago
    If you have to cut red tape for certain projects, the tape probably shouldn't exist in the first place. edit: for instance, if you have e.g. an environmental regulation that is so onerous that exemptions must be doled out for something as sensible as train electrification, then you don't have an environmental review regulation, you have a 'build nothing except what the exemptor decrees' regulation. Which is rather antithetical to the rule of law and good governance.
    - Dalewyn 2y ago
      As a former Californian, you try saying that and you'll be labeled a crazy person railing against the machine. Bureaucracies everywhere tend to protect itself, but California's is particularly vicious. There is a reason many of us call the place Commiefornia.
  - huijzer 2y ago
    I’m getting more and more convinced that this is a main problem all over the West. In Germany, a business owner called Marco Scheel is becoming more and more popular by being very outspoken about how bureaucracy is hindering him. His company is called Nordwolle by the way. They make clothing out of sheep wool. They spend a lot of effort finding the right type of wool so they don’t need chemicals to paint it. One major example which Marco first became popular with was that he owned a barn but wasn’t allowed to use it for the factory since it was a farm on paper. The government told him to move to a designated factory area. He argued that it made no sense since he was living in a very remote area, and the barn was of high quality. What else should he do with the barn? Why would he need to build something new somewhere else? The barn was there already and stood already for hundreds of years. His most popular quote is something along the lines of “we can’t all sit with a Chai latte and a MacBook in a coworking space in Berlin and make the 5th dating app. We need some people who do that but not everyone. Some people need to make things with their hands! And for that I need space! I don’t need glass fibre. I need space!”
declan_roberts 2y ago
19 million annually. I don't think the juice is worth the squeeze here. They should focus on making Caltrain run reliably timely, and safely for the passengers. Once we get the ridership numbers up we can easily make up for the electricity efficiency.
- Prosammer 2y ago
  Caltrain runs reliably and safely for me, can you elaborate?
  - declan_roberts 2y ago
    The $19 million for regenerative breaking can be used to extend lines or add new stations. We can make up for energy efficiency later.
    - renhanxue 2y ago
      I think you completely misunderstood the article. It says that the electricity used to power these trains was estimated to cost $19m a year, but the trains are a bit more efficient than expected, so the new estimate is only $16.5m/year. Most if not all electric trains powered by overhead wires have regenerative braking that feeds back to the grid as standard, and Caltrain's new Stadler units definitely do. Nobody paid extra for regenerative braking, it's just the default way to do things on electric trains, to the point that it'd be weird not to have it. Even diesel-electrics often have a kind of regenerative braking, but they don't have anywhere to store the recovered energy so they just convert it to heat via huge resistors.
      - Symbiote 2y ago
        There's additional cost for the transformers powering the caternary above the track to allow them to receive power, not just send it. However, since this has been normal in Europe and Asia for decades, I doubt the additional expense is significant.
- 2y ago
aetherspawn 2y ago
Train technology is so behind compared to road electric vehicles. Companies that build train batteries have been trying to sell to us (car OEMs) lately, and we look at the battery specs and battery management system capabilities and go uhhhh… On the motor and control fronts as well.
- s0rce 2y ago
  Why? Just build more trains any train infrastructure is so much better than cars, they barely need improvement, they just need to be built
  - aetherspawn 2y ago
    But for example if they used PMM squirrel cage motors etc, they would be nice and smooth, cheaper to build, more energy efficient. On the battery front, using car-style or truck-style EV battery modules would be more robust and would reduce cost by somewhere in the order of 50%. Instead, most trains still use induction motors (this is the high pitch whine you hear) and many train battery designs use industrial style rack mount batteries, with screw terminals, controlled by a massive PLC cabinet. In eMobility the controls are handled by a small safety-rated microcontroller.
    - adgjlsfhk1 2y ago
      What are you talking about? The noise you hear from trains is the wheels. Battery trains basically don't exist because of this cool invention called a wire and pantograph.
      - deleted 2y ago
        [deleted]
      - aetherspawn 2y ago
        The “nice smooth trains” that commenters are talking about use a pantograph, transformer and small on-board battery, and can go a small distance (few kms) through tunnels and between track segments with the pantograph lowered. The power system after the battery is similar to older model electric vehicles.
justinzollars 2y ago
> With the agency expecting approximately $6 million annually in energy credits from the California Air Resources Board’s Low Carbon Fuel Standard Program the first year of electric service will have lower fuel costs than the previous diesel service Thats the key. Without the subsidy its more expensive and less efficient than carbon based fuel. In the long run we are worse off, because the subsidy can't last forever.
- kibwen 2y ago
  > Without the subsidy its more expensive and less efficient than carbon based fuel. If markets actually worked for long-term decisionmaking and were therefore capable of pricing in negative externalities, then factoring in the cost of causing Earth to asymptotically approach Venus would change this calculus.
- renhanxue 2y ago
  They've significantly increased the timetable frequency though, so they're running more trains, and those trains are accelerating and running much faster than the old diesel-electrics. I don't think you're comparing like for like.
- hamandcheese 2y ago
  > Currently, Caltrain is providing that power to the grid free of charge as there is no legal requirement for the agency to be reimbursed for the energy generated. With further investment in energy storage it sounds like they could nearly cover a lost subsidy. Moreover, the improved service from electric (faster acceleration and better air quality) seem very worthwhile.
- ghouse 2y ago
  This is because PG&E retail is about 2.5x the national average. Also, worth noting in the event the conclusions are extrapolated to diesel over the road transportation: train diesel is much less expensive as it's exempt from fuel (state and federal) taxes.
- djaychela 2y ago
  >In the long run we are worse off, because the subsidy can't last forever. You're making the classic error here of not factoring the externalities involved - the pollution and other issues from fossil fuels. If they were actually being paid for then electricity would be much cheaper. Fossil fuels get a defacto subsidy by being able to pollute the environment without any cost.
lacker 2y ago
They claim that "Caltrain is running its service on 100% renewable energy", but they are connected to the same grid as everyone else. It doesn't really make sense to say, half of our electricity is green, so customer X is renewable, but customer Y is not renewable.
- skykooler 2y ago
  It doesn't physically, but it does financially. Power generation is not free after all, so any power station, be it renewable or non-renewable, will only be producing as long as people are buying electricity from it.
- pm90 2y ago
  You can generally choose what kind of power generation mix you want from a utility. eg I am on a 100% renewable plan.
  - timewizard 2y ago
    Out of the 25GW being generated right now only 3GW are renewable. There is a corner where there is more demand from "100% renewable" customers than there actually is available renewable energy. There is no point at which this gets made up.
    - vmladenov 2y ago
      I’m not sure where your figures are coming from, did you mean at the moment of posting your comment? If you look at the integral over the year, California does decently well[1] on renewables, and the people paying for it help blunt the competitive edge of the tremendous federal subsidies enjoyed by fossil fuels. [1]https://www.energy.ca.gov/data-reports/energy-almanac/california-electricity-data/2023-total-system-electric-generation https://www.energy.ca.gov/data-reports/energy-almanac/califo...
      - timewizard 2y ago
        > did you mean at the moment of posting your comment? Yes, right this moment. You can see this here: https://www.caiso.com/todays-outlook/supply https://www.caiso.com/todays-outlook/supply > does decently well[1] on renewables Technically it does decently well on combined "non greenhouse gas + renewables." This is a rather self serving categorization of generation sources and might not be what people buying "100% renewable" energy think they're actually getting. In any case, subtracting Nuclear and Hydro, if more than half the kWh purchased in the state are purchased as "100% renewable", they cannot all be possibly served by renewables even in the aggregate.
benced 2y ago
This literally doesn’t matter. The energy consumption of a train is trivial compared to displacing cars. If there was a way to trade this savings for higher speed, ridership, or frequency, it would be worth it. (If there’s not, this is a free win and yay - but it’s the wrong focus)
- winrid 2y ago
  At least it's a win for air quality for the people that live near the tracks. You could smell and taste the old diesels, was pretty annoying.
  - rsanek 2y ago
    really? how close were you living? i lived for years just 3 houses over from the tracks and never even smelled the trains. definitely heard them tho
    - quantified 2y ago
      I'd breathe it as I biked alongside. Maybe prevailing wind helped your air quality.
    - winrid 2y ago
      I lived across the street. Just walking around you smell it when they go by. Not a huge deal but definitely an improvement!
- archagon 2y ago
  Both speed and frequency are significantly up, and I’ve heard ridership is as well. Also, noise and pollution are substantially down. A huge win all around.
acyou 2y ago
They are using less electricity than expected. The article neglects to specify whether this is due to higher than expected efficiency, or higher than expected downtime. Not that there is necessarily a problem with the technology, but energy efficiency estimates should be expected to already be quite accurate, all the technology is super old. If the efficiency is not in fact higher, I think the article is written a little disingenuously, they should really be more specific.
unit149 2y ago
[dead]
fsckboy 2y ago
>regenerative braking on the new trains is generating and sending back to the electric grid approximately 23% of the energy consumed by the system does this make sense? let's round that 23 up to 25%, and say brake energy regeneration is 100% efficient (it's not): one quarter of the energy put into the system comes back out? city driving in a car, you might have your foot on the brake 25% of the time (yes, that's not how it works, just think conceptually) but a train spends a lot of time running, and comparatively a small amount of time braking, and if you were to detach the engine from the train, one doesn't get a sense the train would roll very far unpowered, so while there's momentum to scavenge, it doesn't seem like 25% of the total I'm just thinking, how do these numbers make sense?
- mikepurvis 2y ago
  Firstly, I believe the trains are EMUs, so every bogey is powered rather than having the whole thing hailed by an engine; this is actually a huge benefit of electric as the trains can accelerate to speed much faster when they’re all wheel drive. But to address your main point, the rolling resistance of a train in motion is tiny; basically all the energy cost is at acceleration time— it probably cruises at like 5-10% power.
- Groxx 2y ago
  "rolling very far unpowered" is like the entire point of rail systems
  - RWSen 2y ago
    Exactly. There's a train route here in The Netherlands, from Den Bosch to Utrecht, where the train can coast the last 20 km. That's out of a 48 km trip, so almost half!
  - fsckboy 2y ago
    I would say that's not precisely true. the point of rail systems started out as "big power plant pulls lots of load". Once that was in place, yes, rolling very far unpowered becomes a compelling improvement. a good comparison would be the invention of the travois https://en.wikipedia.org/wiki/Travois https://en.wikipedia.org/wiki/Travois which benefitted from the addition of wheels.
Animats 2y ago
That's good to hear. Especially since the electric trains accelerate so much faster than the Diesel ones did. Have you been next to one at takeoff? They're going about 40MPH before the train has traveled its own length. Probably limited more by standing passengers than power. Most of the energy used accelerating is recovered at the next stop, so the fast acceleration does not consume much energy.
- ghouse 2y ago
  > Most of the energy used accelerating is recovered at the next stop, so the fast acceleration does not consume much energy. Not "most," but a lot. From the article: > regenerative braking on the new trains is generating and sending back to the electric grid approximately 23% of the energy consumed by the system
  - basiccalendar74 2y ago
    it is 23% of total energy. if you consider only acceleration energy, it will be much larger percentage, probably 80% (as in electric cars).
- acchow 2y ago
  > so the fast acceleration does not consume much energy Also, acceleration has no effect on the energy if you’re trying to hit the same target speed (unless there is friction, in which case you’d use less energy with higher acceleration)
apexalpha 2y ago
While this sounds like good news it's very odd to me that a project the size of Caltrain would completely forget about regenerative breaking when calculating the electricity usage.
savrajsingh 2y ago
I can’t believe the New York City subway does not have this technology. We are currently breathing brake dust in the subway.
gc9 2y ago
If the renewably sourced power is purchased from big hydroelectric dams, the institutional price might depend on how full the reservoirs are. Power costs might be higher in drier years.

340 points by ssuds 2y ago

I mean, this is good news, but why was the efficiency of the system so misunderstood at the design phase? I hope someone's interested enough to find out!

crocal 2y ago
Ahoi! Participated to the development of a simulation tool for that purpose. Many factors need to be taken into account: - The gradients of the track - How agressively you want to drive at different time of the day - How many trains - The timing of the trains. When one train brakes, it can power another one that accelerates at the same moment - The efficiency of the power chain - The resistance model of the train With so many parameters the results can be quite volatile. However, rule of the thumb in the business is that 30% saving can be achieved with good energy management. Hope this clarifies a little. Update: bullet points
- skrap 2y ago
  Interesting! Thanks for the great info. Do you know if anyone will have the opportunity to integrate observations into the model so it can continue to improve?
  - crocal 2y ago
    We did use actual data from existing lines to measure the gap between our models and reality. We were +/- 5% accurate.
djaychela 2y ago
Maybe they didn't factor in ridership on certain part of the track gradient, which would lead to more regen braking than expected?

jeffbee 2y ago

It's hilarious but sad to watch Americans learn things that agencies abroad already know. The other example of this I saw today was that in NYC the congestion pricing has "surprisingly" slashed the number of car crashes and injuries in Manhattan. Like, duh.

readdit 2y ago
I feel this is positive news moving in a positive direction. Do you suggest not doing anything to improve the situation? We can’t go back in time. But we can help ourselves in the future.
- ninetyninenine 2y ago
  I feel this improvement is negligible. I doubt you'll see any meaningful change in your lifetime. At best you'll see an electric car renaissance. But the infra for trains and public transit? Doubtful.
  - readdit 2y ago
    It’s still a positive change an I’m all for it.
    - ninetyninenine 2y ago
      I'm all for positive change too. But as someone who isn't delusional, I have to account for practicality rather then dreaming about an unrealistic future.
- dhosek 2y ago
  I think it’s more that Americans seem to be surprised by things that people in other countries have known for decades. Meanwhile, the current administration is trying to send us back to the 19th century in civil rights, healthcare and energy policy.
  - 2y ago

blintz 2y ago

The electric Caltrain is so wonderful. It’s way quieter, the cars have nicer interiors, and it is running faster and more frequently than before. Between this, the new BART cars (also much quieter!), and Muni hitting a reliability & satisfaction records, there’s really a transit renaissance going on in the Bay Area. I really hope we can keep this going!

ninetyninenine 2y ago
Haha. Doubtful. In your lifetime you won't see any transit system in the bay area that approaches anything remotely close to what you see in places like Tokyo or NYC. I get that there's improvement but like it's still rather pathetic compared to almost everywhere else across the pond.
- lswainemoore 2y ago
  Why so negative? Given that the served population is conservatively a quarter of either of those areas, doesn't seem like a fair comparison. More to the point, I've been favorably impressed with the transit options since moving here, and in terms of reliability it's been better than NYC, though obviously there are fewer trains/branches. I'd love to see BART open later, like NYC, but even Tokyo trains stop at midnight.
  - astrange 2y ago
    NYC is more or less the only system in the world that runs all night like that. It makes it very hard to do maintenance.
    - frosted-flakes 2y ago
      And NYC can do that because most of it's lines have three or four tracks.
  - ninetyninenine 2y ago
    It's fair. NYC is 8.8 million, bay area is 7 million. Tokyo is about double that. Not being negative. Being realistic. It's unfortunate that being realistic often is negative. Transit here is garbage. You either luck out and live and work near transit or you're like most people and have to drive. A couple million in energy savings doesn't mean anything compared to the amount wasted by cars.

zer0zzz 2y ago

Finally some good news

deleted 2y ago

[deleted]

two_handfuls 2y ago

Another cool thing in the article that I didn't know personally: Caltrain runs on 100% renewable power!

benatkin 2y ago
That shouldn't be put forth as a goal. It's how Germany got rid of all its nuclear plants and has to keep burning coal and buying fuel from Russia.
- blamazon 2y ago
  It's also how Scotland ended up harnessing their wind power, much to the consternation of one American capitalist...

whyenot 2y ago

It's great, but it took more than 20 years to get here due to environmental reviews and shaky funding. ...and this was just re-fitting an existing, relatively short stretch of track! We (as Californians) have GOT to do better than this! There are huge infrastructure projects that we need to undertake in the coming years. We have got to cut the red tape and properly fund projects.

sunday_serif 2y ago
Completely agree! The hard parts seems to be figuring out (1) how to cut red tape for only certain projects and (2) figuring out what red tape to keep. Chesterton's fence and all that.
- thereisnospork 2y ago
  If you have to cut red tape for certain projects, the tape probably shouldn't exist in the first place. edit: for instance, if you have e.g. an environmental regulation that is so onerous that exemptions must be doled out for something as sensible as train electrification, then you don't have an environmental review regulation, you have a 'build nothing except what the exemptor decrees' regulation. Which is rather antithetical to the rule of law and good governance.
  - Dalewyn 2y ago
    As a former Californian, you try saying that and you'll be labeled a crazy person railing against the machine. Bureaucracies everywhere tend to protect itself, but California's is particularly vicious. There is a reason many of us call the place Commiefornia.
- huijzer 2y ago
  I’m getting more and more convinced that this is a main problem all over the West. In Germany, a business owner called Marco Scheel is becoming more and more popular by being very outspoken about how bureaucracy is hindering him. His company is called Nordwolle by the way. They make clothing out of sheep wool. They spend a lot of effort finding the right type of wool so they don’t need chemicals to paint it. One major example which Marco first became popular with was that he owned a barn but wasn’t allowed to use it for the factory since it was a farm on paper. The government told him to move to a designated factory area. He argued that it made no sense since he was living in a very remote area, and the barn was of high quality. What else should he do with the barn? Why would he need to build something new somewhere else? The barn was there already and stood already for hundreds of years. His most popular quote is something along the lines of “we can’t all sit with a Chai latte and a MacBook in a coworking space in Berlin and make the 5th dating app. We need some people who do that but not everyone. Some people need to make things with their hands! And for that I need space! I don’t need glass fibre. I need space!”

declan_roberts 2y ago

19 million annually. I don't think the juice is worth the squeeze here. They should focus on making Caltrain run reliably timely, and safely for the passengers. Once we get the ridership numbers up we can easily make up for the electricity efficiency.

Prosammer 2y ago
Caltrain runs reliably and safely for me, can you elaborate?
- declan_roberts 2y ago
  The $19 million for regenerative breaking can be used to extend lines or add new stations. We can make up for energy efficiency later.
  - renhanxue 2y ago
    I think you completely misunderstood the article. It says that the electricity used to power these trains was estimated to cost $19m a year, but the trains are a bit more efficient than expected, so the new estimate is only $16.5m/year. Most if not all electric trains powered by overhead wires have regenerative braking that feeds back to the grid as standard, and Caltrain's new Stadler units definitely do. Nobody paid extra for regenerative braking, it's just the default way to do things on electric trains, to the point that it'd be weird not to have it. Even diesel-electrics often have a kind of regenerative braking, but they don't have anywhere to store the recovered energy so they just convert it to heat via huge resistors.
    - Symbiote 2y ago
      There's additional cost for the transformers powering the caternary above the track to allow them to receive power, not just send it. However, since this has been normal in Europe and Asia for decades, I doubt the additional expense is significant.
2y ago

aetherspawn 2y ago

Train technology is so behind compared to road electric vehicles. Companies that build train batteries have been trying to sell to us (car OEMs) lately, and we look at the battery specs and battery management system capabilities and go uhhhh… On the motor and control fronts as well.

s0rce 2y ago
Why? Just build more trains any train infrastructure is so much better than cars, they barely need improvement, they just need to be built
- aetherspawn 2y ago
  But for example if they used PMM squirrel cage motors etc, they would be nice and smooth, cheaper to build, more energy efficient. On the battery front, using car-style or truck-style EV battery modules would be more robust and would reduce cost by somewhere in the order of 50%. Instead, most trains still use induction motors (this is the high pitch whine you hear) and many train battery designs use industrial style rack mount batteries, with screw terminals, controlled by a massive PLC cabinet. In eMobility the controls are handled by a small safety-rated microcontroller.
  - adgjlsfhk1 2y ago
    What are you talking about? The noise you hear from trains is the wheels. Battery trains basically don't exist because of this cool invention called a wire and pantograph.
    - deleted 2y ago
      [deleted]
    - aetherspawn 2y ago
      The “nice smooth trains” that commenters are talking about use a pantograph, transformer and small on-board battery, and can go a small distance (few kms) through tunnels and between track segments with the pantograph lowered. The power system after the battery is similar to older model electric vehicles.

justinzollars 2y ago

> With the agency expecting approximately $6 million annually in energy credits from the California Air Resources Board’s Low Carbon Fuel Standard Program the first year of electric service will have lower fuel costs than the previous diesel service Thats the key. Without the subsidy its more expensive and less efficient than carbon based fuel. In the long run we are worse off, because the subsidy can't last forever.

kibwen 2y ago
> Without the subsidy its more expensive and less efficient than carbon based fuel. If markets actually worked for long-term decisionmaking and were therefore capable of pricing in negative externalities, then factoring in the cost of causing Earth to asymptotically approach Venus would change this calculus.
renhanxue 2y ago
They've significantly increased the timetable frequency though, so they're running more trains, and those trains are accelerating and running much faster than the old diesel-electrics. I don't think you're comparing like for like.
hamandcheese 2y ago
> Currently, Caltrain is providing that power to the grid free of charge as there is no legal requirement for the agency to be reimbursed for the energy generated. With further investment in energy storage it sounds like they could nearly cover a lost subsidy. Moreover, the improved service from electric (faster acceleration and better air quality) seem very worthwhile.
ghouse 2y ago
This is because PG&E retail is about 2.5x the national average. Also, worth noting in the event the conclusions are extrapolated to diesel over the road transportation: train diesel is much less expensive as it's exempt from fuel (state and federal) taxes.
djaychela 2y ago
>In the long run we are worse off, because the subsidy can't last forever. You're making the classic error here of not factoring the externalities involved - the pollution and other issues from fossil fuels. If they were actually being paid for then electricity would be much cheaper. Fossil fuels get a defacto subsidy by being able to pollute the environment without any cost.

lacker 2y ago

They claim that "Caltrain is running its service on 100% renewable energy", but they are connected to the same grid as everyone else. It doesn't really make sense to say, half of our electricity is green, so customer X is renewable, but customer Y is not renewable.

skykooler 2y ago
It doesn't physically, but it does financially. Power generation is not free after all, so any power station, be it renewable or non-renewable, will only be producing as long as people are buying electricity from it.
pm90 2y ago
You can generally choose what kind of power generation mix you want from a utility. eg I am on a 100% renewable plan.
- timewizard 2y ago
  Out of the 25GW being generated right now only 3GW are renewable. There is a corner where there is more demand from "100% renewable" customers than there actually is available renewable energy. There is no point at which this gets made up.
  - vmladenov 2y ago
    I’m not sure where your figures are coming from, did you mean at the moment of posting your comment? If you look at the integral over the year, California does decently well[1] on renewables, and the people paying for it help blunt the competitive edge of the tremendous federal subsidies enjoyed by fossil fuels. [1]https://www.energy.ca.gov/data-reports/energy-almanac/california-electricity-data/2023-total-system-electric-generation https://www.energy.ca.gov/data-reports/energy-almanac/califo...
    - timewizard 2y ago
      > did you mean at the moment of posting your comment? Yes, right this moment. You can see this here: https://www.caiso.com/todays-outlook/supply https://www.caiso.com/todays-outlook/supply > does decently well[1] on renewables Technically it does decently well on combined "non greenhouse gas + renewables." This is a rather self serving categorization of generation sources and might not be what people buying "100% renewable" energy think they're actually getting. In any case, subtracting Nuclear and Hydro, if more than half the kWh purchased in the state are purchased as "100% renewable", they cannot all be possibly served by renewables even in the aggregate.

benced 2y ago

This literally doesn’t matter. The energy consumption of a train is trivial compared to displacing cars. If there was a way to trade this savings for higher speed, ridership, or frequency, it would be worth it. (If there’s not, this is a free win and yay - but it’s the wrong focus)

winrid 2y ago
At least it's a win for air quality for the people that live near the tracks. You could smell and taste the old diesels, was pretty annoying.
- rsanek 2y ago
  really? how close were you living? i lived for years just 3 houses over from the tracks and never even smelled the trains. definitely heard them tho
  - quantified 2y ago
    I'd breathe it as I biked alongside. Maybe prevailing wind helped your air quality.
  - winrid 2y ago
    I lived across the street. Just walking around you smell it when they go by. Not a huge deal but definitely an improvement!
archagon 2y ago
Both speed and frequency are significantly up, and I’ve heard ridership is as well. Also, noise and pollution are substantially down. A huge win all around.

acyou 2y ago

They are using less electricity than expected. The article neglects to specify whether this is due to higher than expected efficiency, or higher than expected downtime. Not that there is necessarily a problem with the technology, but energy efficiency estimates should be expected to already be quite accurate, all the technology is super old. If the efficiency is not in fact higher, I think the article is written a little disingenuously, they should really be more specific.

unit149 2y ago

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fsckboy 2y ago

>regenerative braking on the new trains is generating and sending back to the electric grid approximately 23% of the energy consumed by the system does this make sense? let's round that 23 up to 25%, and say brake energy regeneration is 100% efficient (it's not): one quarter of the energy put into the system comes back out? city driving in a car, you might have your foot on the brake 25% of the time (yes, that's not how it works, just think conceptually) but a train spends a lot of time running, and comparatively a small amount of time braking, and if you were to detach the engine from the train, one doesn't get a sense the train would roll very far unpowered, so while there's momentum to scavenge, it doesn't seem like 25% of the total I'm just thinking, how do these numbers make sense?

mikepurvis 2y ago
Firstly, I believe the trains are EMUs, so every bogey is powered rather than having the whole thing hailed by an engine; this is actually a huge benefit of electric as the trains can accelerate to speed much faster when they’re all wheel drive. But to address your main point, the rolling resistance of a train in motion is tiny; basically all the energy cost is at acceleration time— it probably cruises at like 5-10% power.
Groxx 2y ago
"rolling very far unpowered" is like the entire point of rail systems
- RWSen 2y ago
  Exactly. There's a train route here in The Netherlands, from Den Bosch to Utrecht, where the train can coast the last 20 km. That's out of a 48 km trip, so almost half!
- fsckboy 2y ago
  I would say that's not precisely true. the point of rail systems started out as "big power plant pulls lots of load". Once that was in place, yes, rolling very far unpowered becomes a compelling improvement. a good comparison would be the invention of the travois https://en.wikipedia.org/wiki/Travois https://en.wikipedia.org/wiki/Travois which benefitted from the addition of wheels.

Animats 2y ago

That's good to hear. Especially since the electric trains accelerate so much faster than the Diesel ones did. Have you been next to one at takeoff? They're going about 40MPH before the train has traveled its own length. Probably limited more by standing passengers than power. Most of the energy used accelerating is recovered at the next stop, so the fast acceleration does not consume much energy.

ghouse 2y ago
> Most of the energy used accelerating is recovered at the next stop, so the fast acceleration does not consume much energy. Not "most," but a lot. From the article: > regenerative braking on the new trains is generating and sending back to the electric grid approximately 23% of the energy consumed by the system
- basiccalendar74 2y ago
  it is 23% of total energy. if you consider only acceleration energy, it will be much larger percentage, probably 80% (as in electric cars).
acchow 2y ago
> so the fast acceleration does not consume much energy Also, acceleration has no effect on the energy if you’re trying to hit the same target speed (unless there is friction, in which case you’d use less energy with higher acceleration)

apexalpha 2y ago

While this sounds like good news it's very odd to me that a project the size of Caltrain would completely forget about regenerative breaking when calculating the electricity usage.

savrajsingh 2y ago

I can’t believe the New York City subway does not have this technology. We are currently breathing brake dust in the subway.

gc9 2y ago

If the renewably sourced power is purchased from big hydroelectric dams, the institutional price might depend on how full the reservoirs are. Power costs might be higher in drier years.