Future of the GWR electrification

[WAO]

It was the horrific overspend on GWEP that stopped work, not Listed buildings. Note the now marooned ATS's!

Chippenham Station had a new footbridge with lifts approved in spite of the Conservation Officer's reservations. He just wanted it toned down a little.

WAO

 

[Benjwri]

A get out of jail card is a good thing, surely…..

Not when ‘jail’ is public scrutiny and building proper infrastructure.

 

[The Ham]

Car batteries can be charged overnight when there is surplus electricity. If road congestion is initially reduced, suppressed demand will cause it to recur unless there is sufficiently large road capacity expansion or road pricing (which I would support but which is almost certainly publicly unacceptable as a general policy).

Yes, you could capture some energy which otherwise would be lost, however you can't run all the electric cars from that.

The issue is more the amount of extra energy needed.

The information below indicates the sort of carbon emissions we could expect from each transport mode with each fuel source, taken from table 6

https://www.sciencedirect.com/science/article/pii/S1361920920307100

Typically cars are always 25% full (as even cars which are 100% are only that full for a very small amount of their time), therefore the carbon emissions (not a direct comparison for energy use, but close enough) are 4.5g/km, this is the same for a 25% loaded regional Hydrogen train (which are less efficient than battery trains).

However even if we lived in a world where every car had 100% of their seats in use, then electric trains would only need to be 50% full and still the cars would be at best using 10% more energy.

However with cars being at 25% full and trains 50% full then there's a need for 4.5 times as much electricity to be produced to move a given number of people. Even with both at 25% loaded it's at least double the energy requirements to move people by BEV car than OHLE trains.

Battery trains would suit somewhere between the two, as hydrogen trains (also 25% loadings) match BEV cars and hydrogen trains are less efficient than battery trains.

Although given just how bad hydrogen power is, the fact that in trains it can match the carbon emissions of BEV cars shows that car travel is also very inefficient.

Also it's worth noting that people using trains would also be more likely walk/cycle more of their short distance travel than those who use cars, so the comparison favours cars slightly more than it should.

 

[slowroad]

Yes, you could capture some energy which otherwise would be lost, however you can't run all the electric cars from that.

The issue is more the amount of extra energy needed.

The information below indicates the sort of carbon emissions we could expect from each transport mode with each fuel source, taken from table 6

https://www.sciencedirect.com/science/article/pii/S1361920920307100

Typically cars are always 25% full (as even cars which are 100% are only that full for a very small amount of their time), therefore the carbon emissions (not a direct comparison for energy use, but close enough) are 4.5g/km, this is the same for a 25% loaded regional Hydrogen train (which are less efficient than battery trains).

However even if we lived in a world where every car had 100% of their seats in use, then electric trains would only need to be 50% full and still the cars would be at best using 10% more energy.

However with cars being at 25% full and trains 50% full then there's a need for 4.5 times as much electricity to be produced to move a given number of people. Even with both at 25% loaded it's at least double the energy requirements to move people by BEV car than OHLE trains.

Battery trains would suit somewhere between the two, as hydrogen trains (also 25% loadings) match BEV cars and hydrogen trains are less efficient than battery trains.

Although given just how bad hydrogen power is, the fact that in trains it can match the carbon emissions of BEV cars shows that car travel is also very inefficient.

Also it's worth noting that people using trains would also be more likely walk/cycle more of their short distance travel than those who use cars, so the comparison favours cars slightly more than it should.

That study assumes electricity is obtained from the national grid under outdated scenarios, none of which deliver net zero. The net zero target was subsequently adopted.

National Grid's net zero commitment | National Grid

Our previous target was to deliver a 70% reduction by 2030 and an 80% reduction by 2050 for direct emissions from a 1990 baseline. We were on track to get there, having delivered a 68% reduction in emissions to date. But we know that we need to be bolder and more ambitious if we are serious...

www.nationalgrid.com

In any case, cars can already be charged overnight, when the grid is less carbon intensive, and, by choice, on the basis of electricity sourced exclusively from zero carbon sources.

Full electrification of the car fleet is a realistic proposition - for lighter used parts of the rail network it may be unaffordable, though battery developments may change that.

(I’ve no idea what average train occupancy is, but I’d be surprised if much over 25%??? The number of passengers per car is about 1.5.)

The common view that trains are a more efficient way of shifting people is based on a narrow view of efficiency - trains are very good at shifting a lot of people, but generally to places that they are not trying to get to. That’s ok in dense urban areas, but limits the scope for modal shift.

 

[The Ham]

That study assumes electricity is obtained from the national grid under outdated scenarios, none of which deliver net zero. The net zero target was subsequently adopted.

National Grid's net zero commitment | National Grid

Our previous target was to deliver a 70% reduction by 2030 and an 80% reduction by 2050 for direct emissions from a 1990 baseline. We were on track to get there, having delivered a 68% reduction in emissions to date. But we know that we need to be bolder and more ambitious if we are serious...

www.nationalgrid.com

It doesn't matter if the grid was 100% coal or 100% nuclear or 100% solar the difference in energy use would be the same.

Yes when we get to 100% renewables (and maintain it) it becomes less of an issue.

The other thing to note was that I was using the worst electric train example:

BEV car 4.5g/km
Intercity electric train 2.1g/km (63 passengers per 250 seat train)
Regional electric train 1.3g/km (112 passengers per 447 seat train)
Urban electric train 1.1g/km (117 passengers per 468 seat train)
High speed electric train 0.7g/km (188 passengers per 750 seat train)
Hydrogen train 4.9 to 4.5g/km

As such for urban and regional electric trains the energy use is around 4 times lower than BEV cars rather than the about 2 times for intercity trains.

In any case, cars can already be charged overnight, when the grid is less carbon intensive, and, by choice, on the basis of electricity sourced exclusively from zero carbon sources.

The issue is that only works up to a point, once you get too many BEV cars you won't have the spare capacity overnight.

Again, the point was more to do with the amount of energy needed not how it was produced, I was using g/km as a reasonable guide to compare actual energy use.

Full electrification of the car fleet is a realistic proposition - for lighter used parts of the rail network it may be unaffordable, though battery developments may change that.

(I’ve no idea what average train occupancy is, but I’d be surprised if much over 25%??? The number of passengers per car is about 1.5.)

The common view that trains are a more efficient way of shifting people is based on a narrow view of efficiency - trains are very good at shifting a lot of people, but generally to places that they are not trying to get to. That’s ok in dense urban areas, but limits the scope for modal shift.

Looking at the capacity data from RAI0201 they lowest city daily loading is 26.1% and that's for Cambridge. Whilst Cambridge does see significant rail use, it's hardly one of our desist city.

The highest three (London Bridge, Manchester and Leeds in no particular order) all have higher than 55% of the seats used across the day.

Across all the cities listed the daily average is 42%.

For clarification, that from first to last service, not just daytime services.

Now whilst that's only looking at cities, it's worth remembering that is where the majority of train services run to and from and so whilst other locations may not be as busy you'd need a lot of places which were a lot below 25% to drag the average to below 25%.

Yes car occupancy is 1.5 (which assuming 5 seats is 30%, yes there's 2 seats but then there's also 7 seaters so on average 5 seats would likely be fair) however you'd probably need cars to be at 30% and intercity rail to be around 20% to even get close to the energy use being close. However for other rail it would probably need to be around 13%.

However, the thing is, as long as you don't increase the number of trains you can increase the number of people travelling by train and the energy per person reduces.

If we assume that rail is about 20% then there's plenty of capacity to add more people to those services without increasing the number of trains needed.

It's also worth noting that lengthing trains doesn't increase the energy use proportionally to the number of coaches, so even if we were to start to need more capacity, the energy efficient thing to do is to lengthen the trains rather than run more and so keep the emissions per passenger km low.

 

[slowroad]

It doesn't matter if the grid was 100% coal or 100% nuclear or 100% solar the difference in energy use would be the same.

Yes when we get to 100% renewables (and maintain it) it becomes less of an issue.

The other thing to note was that I was using the worst electric train example:

BEV car 4.5g/km
Intercity electric train 2.1g/km (63 passengers per 250 seat train)
Regional electric train 1.3g/km (112 passengers per 447 seat train)
Urban electric train 1.1g/km (117 passengers per 468 seat train)
High speed electric train 0.7g/km (188 passengers per 750 seat train)
Hydrogen train 4.9 to 4.5g/km

As such for urban and regional electric trains the energy use is around 4 times lower than BEV cars rather than the about 2 times for intercity trains.



The issue is that only works up to a point, once you get too many BEV cars you won't have the spare capacity overnight.

Again, the point was more to do with the amount of energy needed not how it was produced, I was using g/km as a reasonable guide to compare actual energy use.



Looking at the capacity data from RAI0201 they lowest city daily loading is 26.1% and that's for Cambridge. Whilst Cambridge does see significant rail use, it's hardly one of our desist city.

The highest three (London Bridge, Manchester and Leeds in no particular order) all have higher than 55% of the seats used across the day.

Across all the cities listed the daily average is 42%.

For clarification, that from first to last service, not just daytime services.

Now whilst that's only looking at cities, it's worth remembering that is where the majority of train services run to and from and so whilst other locations may not be as busy you'd need a lot of places which were a lot below 25% to drag the average to below 25%.

Yes car occupancy is 1.5 (which assuming 5 seats is 30%, yes there's 2 seats but then there's also 7 seaters so on average 5 seats would likely be fair) however you'd probably need cars to be at 30% and intercity rail to be around 20% to even get close to the energy use being close. However for other rail it would probably need to be around 13%.

However, the thing is, as long as you don't increase the number of trains you can increase the number of people travelling by train and the energy per person reduces.

If we assume that rail is about 20% then there's plenty of capacity to add more people to those services without increasing the number of trains needed.

It's also worth noting that lengthing trains doesn't increase the energy use proportionally to the number of coaches, so even if we were to start to need more capacity, the energy efficient thing to do is to lengthen the trains rather than run more and so keep the emissions per passenger km low.

I’ve never seen any evidence that energy supply limitations for zero carbon electricity will inhibit the uptake of EVs. And the CCC doesn’t think so. Fundamentally, energy use doesn’t matter if you get from zero carbon sources. Cars also have the potential to return energy to the grid at times of high demand, something of high social benefit.

 

[The Ham]

I’ve never seen any evidence that energy supply limitations for zero carbon electricity will inhibit the uptake of EVs. And the CCC doesn’t think so. Fundamentally, energy use doesn’t matter if you get from zero carbon sources. Cars also have the potential to return energy to the grid at times of high demand, something of high social benefit.

Until we reach 100% zero carbon sources any extra energy needed to result in the same outcome (for example 1 person moved 1km) is more carbon emission than it's otherwise needed.

Whilst the amounts are small, a few grams per km, there's a few things to note.
1) we are a some way from all cars being BEV's
2) electric trains are more energy efficient than the most efficient cars
3) on comparable loading levels inefficient hydrogen trains compare with (or are slightly better) than the most efficient cars
4) as we're talking about billions of km's travelled for the whole of the UK, the impact would be noticeable even if the shift to rail was fairly limited

If in average every tax payer was given a grant of £1,000 and that resulted in every car (highly unlikely, as they would realistically mostly only get you a free wall charger, most scrappage schemes work on £2,000+) becoming a BEV that might be good, however for the same cost we could provide free public transport for 12 months (probably longer).

 

[Bikeman78]

I think in Poland they have a sizable DMU fleet for little used rural lines. EU legislation is making it hard to procure new diesel trains, so Poland simply said - "okay we'll just electrify the branches". And these are minor rural lines with the inefficient 3kV DC system. The only place with a more backwards approach to railway electrification is the USA.

The Belgians have been electrifying basket case lines since the 1990s. Even Mol to Hasselt has been done. Until 2002 it had a two hourly service with a short loco hauled set. It went hourly when the Alstom DMUs arrived. There's a few lines still to be done. There has been talk of battery EMUs.

 

[Class 170101]

Are any other countries using ‘discontinuous electrification’?

It is very telling that I haven’t heard of any.

Depends, I think, on what you mean by Discontinuous in context of Railway Electrification.

Does Holland (Netherlands) not have this? I'm sure I've seen river bridges where the wire stops and restarts on the other side?

 

[Class15]

Depends, I think, on what you mean by Discontinuous in context of Railway Electrification.

Does Holland (Netherlands) not have this? I'm sure I've seen river bridges where the wire stops and restarts on the other side?

Isn’t that coasting?

I more mean what is being done in Wales with batteries.

 

[Trainbike46]

Depends, I think, on what you mean by Discontinuous in context of Railway Electrification.

Does Holland (Netherlands) not have this? I'm sure I've seen river bridges where the wire stops and restarts on the other side?

Isn’t that coasting?

I more mean what is being done in Wales with batteries.

The bridges in the Netherlands are crossed by coasting. There are some adjustments to the pantograph so it can handle a missing section of OHLE without having to lower it first, but the train is unpowered while crossing it.

 

[Class 170101]

The bridges in the Netherlands are crossed by coasting. There are some adjustments to the pantograph so it can handle a missing section of OHLE without having to lower it first, but the train is unpowered while crossing it.

But is there an electrical feed under the crossing or is it simply end fed?

 

[MarkyT]

But is there an electrical feed under the crossing or is it simply end fed?

You could do either at a cost clearly and subject to demand requirements. Batteries make coasting 'assured'!

 

[Snow1964]

It was the horrific overspend on GWEP that stopped work, not Listed buildings. Note the now marooned ATS's!

Chippenham Station had a new footbridge with lifts approved in spite of the Conservation Officer's reservations. He just wanted it toned down a little.

It was only few months ago the final lift (step free) was installed, the north side access on Chippenham station new footbridge. Roughly 6 years after work was semi-permanently paused.

The local understanding is the old bridge can be lifted up and spacers inserted, presumably on a frame on a multi-wheel transporter with jacks. Just because it is listed doesn't mean permission will never be granted to move it about half a metre. Most conservation officers take the view that anything that assists listed structures being preserved for next few decades is better than letting it rot.

 

[MarkyT]

It was only few months ago the final lift (step free) was installed, the north side access on Chippenham station new footbridge. Roughly 6 years after work was semi-permanently paused.

The local understanding is the old bridge can be lifted up and spacers inserted, presumably on a frame on a multi-wheel transporter with jacks. Just because it is listed doesn't mean permission will never be granted to move it about half a metre. Most conservation officers take the view that anything that assists listed structures being preserved for next few decades is better than letting it rot.

And that might be an economical modification if managed well.

 

[Nottingham59]

Are any other countries using ‘discontinuous electrification’?

It is very telling that I haven’t heard of any.

The Germans are doing it as they introduce battery trains on previously diesel lines.

This story from 2022. I don't know how well the projects are going.

Island Hopping for Battery Trains: DB Begins Construction of OLE Islands

Deutsche Bahn (DB) will build electrified overhead contact line islands to intermittently charge battery-powered trains in Schleswig-Holstein.

railway-news.com

Deutsche Bahn (DB) has begun construction of electrified overhead contact line islands that will charge battery-powered trains in the state of Schleswig-Holstein, Germany.

The first catenary masts are currently being erected at Kiel and Büchen stations. The first substations and overhead line islands will then be constructed in the federal state by the end of 2023.

Deutsche Bahn wants to expand this approach to further federal states too, citing Rhineland-Palatinate and the Rhine-Ruhr region as areas where preparatory plans have been completed or initiated.

 

[MarkyT]

The Germans are doing it as they introduce battery trains on previously diesel lines.

I think batteries could drive more wiring. That's their optimum charging infrastructure. More wires add off-wire range, while batteries make the solidity of each grid feeder less critical to overall system reliability, as trains might skip one or more if necessary, within reason. That then limits the capacity of the battery you need. A virtuous circle, perhaps. The feeders might have their own backup too. Storage at all levels?

 

[zwk500]

I more mean what is being done in Wales with batteries.

Trams in Birmingham are doing discontinuous electrification to avoid wires in front of the Town Hall, using batteries to bridge the sections. OpenRailwayMap shows the section to Wolverhampton station as wired but I've been shown photos that clearly don't have wires so not sure what's happening there.

I think batteries could drive more wiring. That's their optimum charging infrastructure. More wires add off-wire range, while batteries make the solidity of each grid feeder less critical to overall system reliability, as trains might skip one or more if necessary, within reason. The feeders could have their own backup too. Storage at all levels? A virtuous circle, perhaps.

Indeed.

 

[Richard Scott]

The Germans are doing it as they introduce battery trains on previously diesel lines.

This story from 2022. I don't know how well the projects are going.

Island Hopping for Battery Trains: DB Begins Construction of OLE Islands

Deutsche Bahn (DB) will build electrified overhead contact line islands to intermittently charge battery-powered trains in Schleswig-Holstein.

railway-news.com

There's only wires at extreme ends of line there for battery charging. In essence think they're really battery trains so not discontinuous electrification there.
I did see some last year when I was there and a monstrosity of a building at Heide to deal with charging. Not sure of green credentials really as constantly making a noise so something always going on and be interesting how much CO2 was emitted erecting necessary infrastructure for one train an hour! Possibly drifting off topic and maybe worth putting in as a speculative thread?

 

[Last Hurrah]

In Bordeaux, trams run on battery for a small stretch in front of the Place de la Bourse, as masts for wiring, were deemed not to be complimentary with the architecture

Viewing photos, one can understand why. .

 

[thecrofter]

A little tangential sorry, but when GWML was electrified in the 2010s, did they retain the grid connection at Hayes? I would assume not but the online sectional appendix (last updated in March) still lists neutral sections at Airport Junction. Is Hayes 132/25 still feeding the airport branch?

In order of your questions: Yes, No.

 

[Sir Felix Pole]

In Bordeaux, trams run on battery for a small stretch in front of the Place de la Bourse, as masts for wiring, were deemed not to be complimentary with the architecture

Viewing photos, one can understand why. .

Bordeaux has a ground power system rather than batteries in the city-centre for aesthetic purposes I think ; Zaragoza in Spain, however, uses batteries in the historic city-centre. Granada, also in Spain, has a couple of sections on battery too.

 

[GraphitProjekt]

In order of your questions: Yes, No.

So it's a classic-only standby FS for an AT line. I know there's another one of those on the MML (Grahame Park FS covering for Borehamwood ATFS), maybe this is a standard practice for AT lines - I have my suspicions about Crowlands FS on the GEML. So what are the neutral sections for? What's the situation where different supplies meet each other?

 

[59CosG95]

So it's a classic-only standby FS for an AT line. I know there's another one of those on the MML (Grahame Park FS covering for Borehamwood ATFS), maybe this is a standard practice for AT lines - I have my suspicions about Crowlands FS on the GEML. So what are the neutral sections for? What's the situation where different supplies meet each other?

Neutral Sections are to separate different phases of the power supply.
Most supplies to the railway at 132kV use 2/3 phases of the supply (e.g. red/yellow, yellow/blue, blue/red), in order to reduce imbalance in the grid.

 

[GraphitProjekt]

Neutral Sections are to separate different phases of the power supply.
Most supplies to the railway at 132kV use 2/3 phases of the supply (e.g. red/yellow, yellow/blue, blue/red), in order to reduce imbalance in the grid.

Oh Indeed,
But what I was wondering is that Kensal Green ATFS (which I believe is 1 grid connection) normally powers everything from Paddington to Maidenhead including the Heathrow Branch - yet the neutral sections Airport Junction (only on the diverging lines) still exist, meaning that the NSs are separating the same supply on each side. Now I learn that the original Hayes 132/25 is still available but not in regular use, so I'm wondering what situation arises where that neutral section would actually be separate different supplies. I think the only scenario for this would be Hayes FS feeding the airport branch to take a bit of load off Kensal Green - perhaps if Kensal Green is suppling XR (something which I've seen mentioned as a possibility).

 

[hwl]

Oh Indeed,
But what I was wondering is that Kensal Green ATFS (which I believe is 1 grid connection) normally powers everything from Paddington to Maidenhead including the Heathrow Branch - yet the neutral sections Airport Junction (only on the diverging lines) still exist, meaning that the NSs are separating the same supply on each side. Now I learn that the original Hayes 132/25 is still available but not in regular use, so I'm wondering what situation arises where that neutral section would actually be separate different supplies. I think the only scenario for this would be Hayes FS feeding the airport branch to take a bit of load off Kensal Green - perhaps if Kensal Green is suppling XR (something which I've seen mentioned as a possibility).

Kensal has two separate feeds and transformers for XR (core) and NR

 

[GraphitProjekt]

Kensal has two separate feeds and transformers for XR (core) and NR

Didn't know that thank you! That makes it just like Pudding Mill Lane on the other side. So 4x connections one of which is always off. If there was an N-2 outage at Pudding Mill Lane, would Kensal Green A be expected to extend through XR core onto the GEML (and vice-versa for a Kensal Green N-2)?

 

[hwl]

Didn't know that thank you! That makes it just like Pudding Mill Lane on the other side. So 4x connections one of which is always off. If there was an N-2 outage at Pudding Mill Lane, would Kensal Green A be expected to extend through XR core onto the GEML (and vice-versa for a Kensal Green N-2)?

Yes a mirror of Pudding Mill Lane
Core certainly, not sure about GEML