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How green are Trains ?

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hwl

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That's probably true because the resistance to motion of the train is lower (per passenger) than for road vehicles. However the weight per person is likely to be greater, and comes into play when the train has to be started from a stop. Regenerative braking reduces but doesn't eliminate this penalty.
Pretty much, it is all simple physics and BR had (energy) cost per stop calculations which I think ranged from £4 (4VEP) to £70 in 1980s prices.
 
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AM9

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Not directly related to the discussion, but very interesting none the less (since we're talking about data):
It's only relevant when shown as CO2 per capita for major countries (say over 50M population).
 
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Taunton

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There are such a wide range of ways to show the figures, generally distorted to present a particular point of view. Rarely taken into account, however, are :

To convey the passengers on the actual journey, the train commonly needs to do a lot of unproductive running. Morning 12-car services arriving in London full may have done empty running to the starting point, then run well under capacity until the final few stops, and then, departing again at 0900, run virtually empty back to the starting point as, unlike cars, there are few or no ways to store them in London in the day.

The Paddington to Penzance train stops at Castle Cary, and that seat is generally not sat in again all the way to Penzance.

I would be surprised if a properly calculated average occupancy came to more than 10% overall.

One that amuses me is the drivers, and thus the service, absolutely depend on them being able to drive by car to the depot for an 0500 shift start as there's no public transport for them - same for going home after a post-midnight finish. And the same for all shifts of rural signalmen.
 

najaB

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I would be surprised if a properly calculated average occupancy came to more than 10% overall.
I wouldn't. With trains over 100% of their rated capacity during the peaks there would need to be a *lot* of ECS moves to bring the average down that low.
 

Journeyman

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Eurostar has long claimed to be carbon-neutral. While it's fairly easy to quantify how much crap a diesel powered loco/vehicle spews out, calculating the environmental impact of an electric train is much trickier, as it very much depends on how the power is generated. However, in recent years there's been a big shift towards nuclear and renewables for traction current generation, which makes it pretty clean as energy goes.

I know the green lobby doesn't like nuclear, but for as long as we're restricted by current technology and demand, it's very efficient, it has an excellent safety record and, as long as the waste is handled properly, it's pretty environmentally-friendly.
 

387star

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There are such a wide range of ways to show the figures, generally distorted to present a particular point of view. Rarely taken into account, however, are :

To convey the passengers on the actual journey, the train commonly needs to do a lot of unproductive running. Morning 12-car services arriving in London full may have done empty running to the starting point, then run well under capacity until the final few stops, and then, departing again at 0900, run virtually empty back to the starting point as, unlike cars, there are few or no ways to store them in London in the day.

The Paddington to Penzance train stops at Castle Cary, and that seat is generally not sat in again all the way to Penzance.

I would be surprised if a properly calculated average occupancy came to more than 10% overall.

One that amuses me is the drivers, and thus the service, absolutely depend on them being able to drive by car to the depot for an 0500 shift start as there's no public transport for them - same for going home after a post-midnight finish. And the same for all shifts of rural signalmen.

Fair point wonder how many drivers won't mind more nights or introducing nights if it meant being able to travel by train to work for all shifts
 

GrimShady

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The following chart is from the Rail Industry Decarbonisation Task Force's report in January this year. The figures date back to DfT's 2007 White Paper, so presumably nobody has redone them since then! Since 2007 cars, planes and electric trains will have improved a bit - cars and planes through better fuel efficiency and electric trains because coal has largely gone from the generation mix and been replaced by renewables.

The notes are worth reading: Data assumes the following load factors: urban bus 20%, intercity coach 60%, intercity rail 40%, all other trains 30%, domestic airlines 70%, and cars 30%. Road, air and diesel-powered rail vehicles’ emissions have been increased to take account of refinery losses and electric powered vehicles take into account losses in the grid.

grams CO2 per passenger km
-----------------------------------------------50--------------100--------------150------------200-------------250
View attachment 61902

Interesting that Class 91 IC225 beats them all including the Pendolinos.
 

Bald Rick

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Eurostar has long claimed to be carbon-neutral. While it's fairly easy to quantify how much crap a diesel powered loco/vehicle spews out, calculating the environmental impact of an electric train is much trickier, as it very much depends on how the power is generated. However, in recent years there's been a big shift towards nuclear and renewables for traction current generation, which makes it pretty clean as energy goes.

I know the green lobby doesn't like nuclear, but for as long as we're restricted by current technology and demand, it's very efficient, it has an excellent safety record and, as long as the waste is handled properly, it's pretty environmentally-friendly.

Given that well over 90% of French electricity is carbon neutral, and that (AIUI) HS1 buys UK electricity on a carbon neutral basis, it’s a fairly easy claim.
 

RT4038

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There are such a wide range of ways to show the figures, generally distorted to present a particular point of view. Rarely taken into account, however, are :

To convey the passengers on the actual journey, the train commonly needs to do a lot of unproductive running. Morning 12-car services arriving in London full may have done empty running to the starting point, then run well under capacity until the final few stops, and then, departing again at 0900, run virtually empty back to the starting point as, unlike cars, there are few or no ways to store them in London in the day.

The Paddington to Penzance train stops at Castle Cary, and that seat is generally not sat in again all the way to Penzance.

I would be surprised if a properly calculated average occupancy came to more than 10% overall.

One that amuses me is the drivers, and thus the service, absolutely depend on them being able to drive by car to the depot for an 0500 shift start as there's no public transport for them - same for going home after a post-midnight finish. And the same for all shifts of rural signalmen.

And the fleet of Network Rail vans, and track machines, and all their staff and contractors, and the delivery of parts to depots, rail and ballast etc etc etc. All adds up.
 

Bald Rick

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I wouldn't. With trains over 100% of their rated capacity during the peaks there would need to be a *lot* of ECS moves to bring the average down that low.

Agreed. You can actually work it out, as passenger km and train km are both published. The former divided by the latter will give you average passengers per train. The answer for 2017/8 is 127 passengers per train. Feels about right.

Now if we knew the average seat/km we could work out occupancy. Given that there are a lot of trains running around with 500+ seats, and not many running with less than 200, I’d say the average seats per train is around 400. 127 is just over 30%.again, this feels right.
 

adamedwards

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Interesting that we worry about empty stock and contra peak trains, but no one does the same for cars. For example I know someone who drives her kids for 45 mins to a private school, despite good local school within walking distance, then does an "ECS" journey home and then reverse for the evening collection. Journeys like this a driving the need to widen the A414! How many cars run most journeys only 25% occupied? (Yet ride a tandem bike to pick up a child and the same drivers ask you if someone fell off!)
 

The Ham

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Interesting that we worry about empty stock and contra peak trains, but no one does the same for cars. For example I know someone who drives her kids for 45 mins to a private school, despite good local school within walking distance, then does an "ECS" journey home and then reverse for the evening collection. Journeys like this a driving the need to widen the A414! How many cars run most journeys only 25% occupied? (Yet ride a tandem bike to pick up a child and the same drivers ask you if someone fell off!)

Indeed, is also point out that few people driving their small cars would be able to achieve 150g/km on a lot of journeys, especially those where there's congestion.

There's also a load of fairly unproductive journeys in cars, such as getting fuel, getting the car serviced, driving around to find a parking space, going and looking at new cars etc. Although there will be those for whom such trips are fairly small (such as only getting fuel whilst at a supermarket, live/work within a short distance of a car maintenance garage, have their own driveway, etc.) these all add up and aren't included in the general milage figures.

As such there's always going to be examples of where the CO2 emissions are going to be worse than the quoted figures.

If also point out that if I go by train on a service which is already running the amount of extra CO2 produced will be very small, whilst if I drive it's all extra. There's also scope for some of the journey to be undertaken by other modes, such as walking or cycling, which wouldn't be as easy when driving (to the extent that few do so).

Of course all this discussion so far had been looking at the use of the vehicles and not the construction in the first place. Although rail had a lot of CO2 required to build the tracks, typical payback periods are 10-30 years. Likewise with most trains only being scraped after 30 years, whilst most cars have a much shorter lifespan.

As an example a typical European car can have something like 250g/km when including lifetime emissions, whilst fairly efficient cars can be around the 170g/km. However even that doesn't account for road maintenance emissions, which as road surfacing and pairing white lines involve a lot of heat so are hardly very green.
 

al78

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They don't pay fuel duty or road tax which given the roads cost money to maintain unless road pricing or a electric car surcharge is introduced to an electricity bill the government would face a £27bn black hole in their budget for fuel duty alone if we all switched to electric cars. As fuel duty makes the government more money than it spends on transport this is another problem meaning taxes will have to rise in other areas.

Wrong. Fuel duty doesn't cover the cost of road transport when all the externalised costs are taken into account (the externalised costs are those which never appear on any balance sheet, because someone else pays them).

https://www.sciencedirect.com/science/article/pii/S0967070X16306345
 

The Ham

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Agreed. You can actually work it out, as passenger km and train km are both published. The former divided by the latter will give you average passengers per train. The answer for 2017/8 is 127 passengers per train. Feels about right.

Now if we knew the average seat/km we could work out occupancy. Given that there are a lot of trains running around with 500+ seats, and not many running with less than 200, I’d say the average seats per train is around 400. 127 is just over 30%.again, this feels right.

There's Government data which shows the numbers of arrival/departures and seating capacity from the country's busiest stations:
https://t.co/jHN91l7dyS?amp=1

That has Manchester with a daily average of 45% and Euston with a daily average of 60%.

Yes there's going to be a lot of stations with much lower, especially those with very tidal flows as is shown by Cambridge with a daily average of 30%.

Do I think that 30% is right? Possibly, but if it's not it'll be only be higher if it is wrong (and probably not that much higher if it is)
 

Antman

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Interesting that Class 91 IC225 beats them all including the Pendolinos.
The chart is utterly skewed by the data that went into it though. Megabus is low because it's got assumed passenger loadings at 50% MORE than intercity trains. From that, I simply take it that if inter city trains were more loaded, or to the same 60%, they'd win (and I suspect that the loading figure used is also too low for the real loadings anyway (it's rare these days to sit on an intercity train that isn't at least 2/3 full for a significant portion of its journey)
 

6Gman

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One that amuses me is the drivers, and thus the service, absolutely depend on them being able to drive by car to the depot for an 0500 shift start as there's no public transport for them - same for going home after a post-midnight finish. And the same for all shifts of rural signalmen.

Er, my father was a footplateman for 30 years. Never owned a car. He had legs. And a bicycle.
 

mikey9

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It is great to see this being discussed at this level from such a wide range of viewpoints. I was doing the same 12-15 years ago (The Story of Stuff, Age of Stupid, Without hot air, David Mackay) but I found people just closed down and turned off when you tried to even discuss the idea that we might need to change.
All power to a 16 year old girl who appears to have caught the imagination of many (including on a relatively obscure rail forum!!).

Keep up the great discussions - some interesting food for thought.
Personally int he last 15 years I have probably moved from thinking we could do something - to despair at the realisation that people just don't seem to be able to look beyond a 5-10 year horizon - unless it is ACTUALLY happening to them in a physical or (significantly) financial manner.
I suspect large scale renewables and nuclear along with massive reductions in our consumerist habits - and carbon rationing are the only way we will change the direction we are headed. How the economy changes to work in that world......well - we lived through wars - and maybe we should be treating this as the same challenge?
 

Antman

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Er, my father was a footplateman for 30 years. Never owned a car. He had legs. And a bicycle.
great. and his depot was how close to home ? And now, given the number of sheds is miniscule due to modern traction, reliability and lack of need for such intensive service and maintenance....
 

387star

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great. and his depot was how close to home ? And now, given the number of sheds is miniscule due to modern traction, reliability and lack of need for such intensive service and maintenance....
London is so expensive people do crazy commutes. Spreading employment to.the peripheries will help
 

thenorthern

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Its important to remember that trains are likely to be more efficient than electric cars as if you think about it with electric cars for me it goes

Power Station > National Grid > Distribution network > BSP substation > Primary Substation > Final Distribution Substation > My Electric meter > Rectified to DC > Stored in a battery > Powered from a Battery > Inverted to 3 phase AC > Powering the car.

Whereby each ">" represents a change and thus a loss of electrical energy.

I am not sure of the distribution systems for trains but given that nearly all trains don't require any battery storage I would assume that electric trains are somewhat more efficient than electric cars are.
 

Bald Rick

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Its important to remember that trains are likely to be more efficient than electric cars as if you think about it with electric cars for me it goes

Power Station > National Grid > Distribution network > BSP substation > Primary Substation > Final Distribution Substation > My Electric meter > Rectified to DC > Stored in a battery > Powered from a Battery > Inverted to 3 phase AC > Powering the car.

Whereby each ">" represents a change and thus a loss of electrical energy.

I am not sure of the distribution systems for trains but given that nearly all trains don't require any battery storage I would assume that electric trains are somewhat more efficient than electric cars are.

That depends on the type of electrification.

For D.C. third rail it is Grid > DNO > Railway HV > Railway traction voltage > Rectified > via a mile or two of think steel rail > traction system input > inverter > powering the train.

On AC systems, you get the same stages, but in a different order (the rectification and one of the the transforming stages moves from the line side to the train).
 

thenorthern

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That depends on the type of electrification.

For D.C. third rail it is Grid > DNO > Railway HV > Railway traction voltage > Rectified > via a mile or two of think steel rail > traction system input > inverter > powering the train.

On AC systems, you get the same stages, but in a different order (the rectification and one of the the transforming stages moves from the line side to the train).

Yes about overhead lines, with third rail though I think I read of the train goes above 80 mph something like 25% of the energy is lost through heat.

Rectifiers and Inverters are in my opinion are often a giant unnecessary waste of energy, a few weeks ago I was at my friends house which has solar panels on the roof and and a storage battery meaning he takes very little electricity off the grid. Looking at the appliances in his house I noticed many of them used DC utilising a power brick rectifier on the cable. Given that all his sockets are BS1363 (standard UK sockets) it means the electricity from the battery and solar panels are DC then inverted then rectified.
 

AM9

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Yes about overhead lines, with third rail though I think I read of the train goes above 80 mph something like 25% of the energy is lost through heat.

Rectifiers and Inverters are in my opinion are often a giant unnecessary waste of energy, a few weeks ago I was at my friends house which has solar panels on the roof and and a storage battery meaning he takes very little electricity off the grid. Looking at the appliances in his house I noticed many of them used DC utilising a power brick rectifier on the cable. Given that all his sockets are BS1363 (standard UK sockets) it means the electricity from the battery and solar panels are DC then inverted then rectified.
Modern power transformers have efficiencies in excess of 90 or even 95%. Anything less than that on a train of say 1.5Mw would be an embarrassment, i.e. 150Kw of heat beneath one car on a four-car EMU would be difficult to handle in the restricted space available. Similarly, rectifiers have near to 100% efficiency. Current designs of semicondictor inverters also have efficiencies approaching 100%. The electrical efficiency of an ac-fed train traction system is pretty good, with quite low resistive losses on the OLE. Low voltage DC trains, despite having no on-board transformer/rectifier are considerably less power efficient from the DC distribution point as they have considerable resistive losses on steel conductor rails because for a given power delivered to the motors, somewhere between 15 and 25% of the power is converted to heating the conductor (and to a lesser amount the DC return in the running rails). That is because the current at 750VDC is 33 times higher than that which flows through the pantograph.
 

Dougal2345

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I've read (on here somewhere I think) that when the roofs of coaches are painted white, there's a considerable saving in air conditioning, so perhaps that should be mandated across the network (assuming that it more than balances out the negative effect of increased heating in winter)
 

edwin_m

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Painting the roof white would if anything slightly reduce heat loss in winter.

London buses got white roofs some years ago and Networkers started off with white roofs (which rapidly became sooty on the diesel variants). GWR's dark green trains actually aren't green at all in that respect!
 

DerekC

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The chart is utterly skewed by the data that went into it though. Megabus is low because it's got assumed passenger loadings at 50% MORE than intercity trains. From that, I simply take it that if inter city trains were more loaded, or to the same 60%, they'd win (and I suspect that the loading figure used is also too low for the real loadings anyway (it's rare these days to sit on an intercity train that isn't at least 2/3 full for a significant portion of its journey)

Loadings may have gone up a bit - but the message that rail is only green if it has high levels of loading is really important. A nearly empty DMU on a rural service is probably as bad as it gets - so a transport policy based on carbon efficiency might very well close rural railways fairly rapidly.
 

6Gman

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Loadings may have gone up a bit - but the message that rail is only green if it has high levels of loading is really important. A nearly empty DMU on a rural service is probably as bad as it gets - so a transport policy based on carbon efficiency might very well close rural railways fairly rapidly.

A thought which has often crossed my mind watching a 153 carrying 6 or 8 passengers ...
 

6Gman

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great. and his depot was how close to home ? And now, given the number of sheds is miniscule due to modern traction, reliability and lack of need for such intensive service and maintenance....

Within walking/ cycling distance.
 

najaB

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A nearly empty DMU on a rural service is probably as bad as it gets - so a transport policy based on carbon efficiency might very well close rural railways fairly rapidly.
Or, alternatively, replace the old diesel mover with something more efficient.
 

squizzler

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Interesting article in the guardian discusses the ongoing modal shift from plane to rail travel including a very compelling comparison of the carbon emissions:

Greta Thunberg's train journey through Europe highlights no-fly movement

With train travel generating 15g of CO2 per kilometre compared with about 100g for flying, environmentally conscious Swedes such as Greta are stopping flying, or at least reducing the number of flights they take. The World Wildlife Foundation released a survey indicating that nearly one in five people in Sweden had opted to travel by train rather than plane for environmental reasons.
 
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