Decarbonising Scotland’s Railways

[gingertom]

Exactly what I was thinking.

rinse and repeat on the west highland.

 

[snowball]

As such a length of OLE would only ever be charging batteries and operating one train it wouldn't need to be a 132kv/440kv grid fed 40MW-capable "proper" feeder station. A small SFC off the local DNO would be adequate, very much cheaper, and quicker to provide than a full-spec/capacity grid connection.

The only issue I can see is what if such a power feed goes offline? Will a train be able to get back north without picking up power?

Even if it was guaranteed never to go offline, it would need to include a large stationary battery, like the rapid charger at West Ealing in the GWR/Vivarail Greenford experiment. Once it includes a big enough battery, going offline for a short period is not a problem.

A battery train using a 10-minute turnround to charge up from flat for a 30-minute journey will draw 3 times the current from the OLE as would be drawn on average by a straight electric during the journey.

 

[HSTEd]

Given the cost of a wood pole line power line in the ~33kV range - wouldn't the cheap option just be to build, or contract with the local DNO to build, a 25kV-0 single phase power line from the railway at Ayr south to Stranraer? It doesn't even have to follow the railway boundary.

It's not as if the railway to Stranraer is really going to operate without the railway to Ayr being operable anyway. If the distance is too far you could fit a single autotransformer at each end and use 25kV-0-25kV

 

[Bald Rick]

A battery train using a 10-minute turnround to charge up from flat for a 30-minute journey will draw 3 times the current from the OLE as would be drawn on average by a straight electric during the journey.

No it wouldn’t. Because the ‘straight electric’ wouldn’t be drawing power the whole time, and at some point be regenerating, which on a battery train goes straight back into the battery.

What you mean is that a battery train and a straight electric will use the same amount of electrical energy for the same journey (ignoring the extra weight of the batteries), and that the average net power drawn would be three times higher for a battery train in a 10 minute turnaround compared to a straight electric on a 30 minute trip, all else being equal. But the words average and net are key.

 

[alf]

What you mean is that a battery train and a straight electric will use the same amount of electrical energy for the same journey (ignoring the extra weight of the batteries)

Are you saying you can push power into batteries at the same rate as a train draws power for its traction motors & hotel load?

 

[NotATrainspott]

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There's a 132kV substation at Glenluce, not far from the railway, and a 33kV in the industrial estate. 33kV would presumably only be suitable for a DC fast charging station at the terminus. If turnarounds won't be long enough for that to be worthwhile, then there's the option of traditional 25kV wiring from Stranraer to Glenluce.

 

[Carntyne]

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There's a 132kV substation at Glenluce, not far from the railway, and a 33kV in the industrial estate. 33kV would presumably only be suitable for a DC fast charging station at the terminus. If turnarounds won't be long enough for that to be worthwhile, then there's the option of traditional 25kV wiring from Stranraer to Glenluce.

There won't be 25kV wires between Girvan and Stranraer. It's pretty clear from the decarbonization strategy.

 

[Bald Rick]

Are you saying you can push power into batteries at the same rate as a train draws power for its traction motors & hotel load?

yes. In fact you can charge at a quicker rate than you discharge. That’s the whole principle of the vivarail fast charge system (and just about every electric car fast charge system)

 

[najaB]

There won't be 25kV wires between Girvan and Stranraer. It's pretty clear from the decarbonization strategy.

While there are currently no plans for 25kV between Girvan and Stranraer, it's too early to completely rule out anything.

 

[Energy]

No it wouldn’t. Because the ‘straight electric’ wouldn’t be drawing power the whole time, and at some point be regenerating, which on a battery train goes straight back into the battery.

What you mean is that a battery train and a straight electric will use the same amount of electrical energy for the same journey (ignoring the extra weight of the batteries), and that the average net power drawn would be three times higher for a battery train in a 10 minute turnaround compared to a straight electric on a 30 minute trip, all else being equal. But the words average and net are key.

With regenerative breaking you'll only need to charge up the energy used to maintain the speed + hotel power + a bit for losses.

 

[Bald Rick]

With regenerative breaking you'll only need to charge up the energy used to maintain the speed + hotel power + a bit for losses.

That depends what happens to the regenerated electricity of course.

 

[Energy]

That depends what happens to the regenerated electricity of course.

Hopefully in a battery unit it goes back to the battery.

 

[Bald Rick]

Hopefully in a battery unit it goes back to the battery.

exactly! But on a straight electric t doesn’t necessarily go back into the electricity network.

 

[Energy]

exactly! But on a straight electric t doesn’t necessarily go back into the electricity network.

Wonder what the energy usage of a train which is regenerative but had to carry heavy batteries vs one which doesn't but just turns the braking energy into heat.

Wonder how discontinuous electrification at both Scotrail and Wales will go, for those who aren't aware the distance for power changeover can be very long

 

[GRALISTAIR]

There won't be 25kV wires between Girvan and Stranraer. It's pretty clear from the decarbonization strategy.

No. Agree totally. More likely Fort Bill gets electrification rather than Stranraer. Ain’t going to happen. Not in my lifetime anyway.

 

[Bald Rick]

Wonder what the energy usage of a train which is regenerative but had to carry heavy batteries vs one which doesn't but just turns the braking energy into heat.

Wonder how discontinuous electrification at both Scotrail and Wales will go, for those who aren't aware the distance for power changeover can be very long

The battery train will win, by a mile. An extra few tonnes on a unit that weighs 120 or so is on the margins.

 

[NotATrainspott]

There won't be 25kV wires between Girvan and Stranraer. It's pretty clear from the decarbonization strategy.

Glenluce isn't Girvan. It'd be the equivalent of the Borders partial electrification scheme: provide a bit of 25kV at the far end of the route where there's a major grid supply point. Whether it makes sense to do this depends on the relative costs. I'm not convinced that hydrogen trains will stack up economically. If you're looking for a way to recharge a BEMU at the end of the line, then a few miles of relatively plain 25kV might be cheaper in some circumstances than a fast charge station needing static batteries or a boost to local supply capacity.

 

[Nottingham59]

If you're looking for a way to recharge a BEMU at the end of the line, then a few miles of relatively plain 25kV might be cheaper in some circumstances than a fast charge station

As such a length of OLE would only ever be charging batteries and operating one train it wouldn't need to be a 132kv/440kv grid fed 40MW-capable "proper" feeder station. A small SFC off the local DNO would be adequate, very much cheaper, and quicker to provide than a full-spec/capacity grid connection.

The one thing that needs to be decided before considering lineside equipment for discontinuous electrification, is for the Scottish Government to specify a standard for off-wire performance for new battery trains. It needs to be a national specification; these BEMUs will cascade around the country as electrification gaps are infilled and new sections of discontinuous electrification are introduced.

Looking at what's available in Europe, I'd say that a sensible specification might be 75 miles / 120km guaranteed range off the wires - measured on gentle gradients and at typical linespeeds, but in all weathers. The Stadler Flirt AKKU claims a range of 150km, but I don't know if that's guaranteed in all temperatures and headwinds: https://www.stadlerrail.com/en/flirt-akku/details/

Once you have a range specified, you can then adjust for terrain. For a particularly hilly line, that might mean that the longest gap between OHLE can only be 60-65 miles, perhaps. I don't know but you could work it out. Then you can plan the recharge strategy for that line.


For Stranraer, the sensible recharge strategy might well be a short length of OHLE, fed by a 25kV feeder cable from the Glenluce substation. Or maybe the future of Stranraer station is to have seven 50kW EV chargers in the carpark, and a 350kW EV supercharger on the platform, with switching to prioritise train recharging? Personally I would have two BEMU versions. One a pure BEMU, and one with a ~200kW "range extender" engine, powered by biodiesel. That's car sized, but should be enough with battery boost and regeneration. That combination could decarbonise the entire Scottish network. There are lots of possibilities, but they all depend on deciding now on a standard BEMU specification for Scotland.

 

[Energy]

The Stadler Flirt AKKU claims a range of 150km, but I don't know if that's guaranteed in all temperatures and headwinds: https://www.stadlerrail.com/en/flirt-akku/details/

It is. Theyve managed 224km in freezing conditions.

 

[vic-rijrode]

It is. Theyve managed 224km in freezing conditions.

I wonder if 50km of that was by sliding along the rails downhill?

 

[NotATrainspott]

The one thing that needs to be decided before considering lineside equipment for discontinuous electrification, is for the Scottish Government to specify a standard for off-wire performance for new battery trains. It needs to be a national specification; these BEMUs will cascade around the country as electrification gaps are infilled and new sections of discontinuous electrification are introduced.

Looking at what's available in Europe, I'd say that a sensible specification might be 75 miles / 120km guaranteed range off the wires - measured on gentle gradients and at typical linespeeds, but in all weathers. The Stadler Flirt AKKU claims a range of 150km, but I don't know if that's guaranteed in all temperatures and headwinds: https://www.stadlerrail.com/en/flirt-akku/details/

Once you have a range specified, you can then adjust for terrain. For a particularly hilly line, that might mean that the longest gap between OHLE can only be 60-65 miles, perhaps. I don't know but you could work it out. Then you can plan the recharge strategy for that line.


For Stranraer, the sensible recharge strategy might well be a short length of OHLE, fed by a 25kV feeder cable from the Glenluce substation. Or maybe the future of Stranraer station is to have seven 50kW EV chargers in the carpark, and a 350kW EV supercharger on the platform, with switching to prioritise train recharging? Personally I would have two BEMU versions. One a pure BEMU, and one with a ~200kW "range extender" engine, powered by biodiesel. That's car sized, but should be enough with battery boost and regeneration. That combination could decarbonise the entire Scottish network. There are lots of possibilities, but they all depend on deciding now on a standard BEMU specification for Scotland.

350kW isn't very much. Rail vehicles would be in the same fast charging class as trucks and aircraft, which will be getting a 2MW fast charge connector.

The move away from natural gas for heating demands means there will need to be fairly major grid upgrades in a lot of areas, including Stranraer. If the cost of these can be spread across the entire town rather than just the railway, it shouldn't be that hard to get the upgrades done.

 

[Nottingham59]

Theyve managed 224km in freezing conditions.

Yes, but that 224km was in a record attempt. I've seen elsewhere that Stadler guarantee 80km. Whatever the range is, the important thing is that it needs to be guaranteed so that you can start to plan your infrastructure around it.

350kW isn't very much.

I thought it was quite a lot, really. The Talent 3 has a total battery capacity of 360-564kWh. See https://www.railvolution.net/news/talent-3-bemu-in-passenger-service Other BEMUs have similar capacities.

So 350kW should allow full recharge in an hour or two. If that's not acceptable, you might need two 350kW superchargers, one at each end of the train - and a BEMU specification that allows you to plug them in, of course! I only suggested 350kW because these are becoming availabe for cars, so should be relatively cheaper with volume production.

there will need to be fairly major grid upgrades in a lot of areas, including Stranraer.

Agreed, this is always going to be an issue. But even without upgrades, at times of low demand, you should be able to take more current without overwhelming the local grid. So perhaps you could run a summer timetable to Stranraer with shorter turnaround times, and a winter timetable with longer layovers?

 

[Carntyne]

Glenluce isn't Girvan. It'd be the equivalent of the Borders partial electrification scheme: provide a bit of 25kV at the far end of the route where there's a major grid supply point. Whether it makes sense to do this depends on the relative costs. I'm not convinced that hydrogen trains will stack up economically. If you're looking for a way to recharge a BEMU at the end of the line, then a few miles of relatively plain 25kV might be cheaper in some circumstances than a fast charge station needing static batteries or a boost to local supply capacity.

It's between Girvan and Stranraer, which isn't going to get 25kV OLE. TS very clear that the wires will go as far as Girvan.

 

[Trainbike46]

It's between Girvan and Stranraer, which isn't going to get 25kV OLE. TS very clear that the wires will go as far as Girvan.

TS only states that Girvan-Stranraer won't be fully electrified, but instead will either be served by hydrogen trains (which in my view don't make sense as the distance really isn't that far) or battery trains (with appropriate charging solutions if needed). If the most appropriate charging solution was a short section of OHLE in Stranraer, then, in my understanding there is nothing in the documents stating that that won't be implemented. you are right that there won't be full Girvan-Stranraer OHLE, but that doesn't seem to be what @NotATrainspott was suggesting, as I understand it they were suggesting OHLE from a sensible grid connection to Stranraer over a short distance, which seems a reasonable option if a charging solution at Stranraer is deemed necessary

I do wonder why these threads always end up focusing on the relative edge cases such as Stranraer, Far North etc. They're not where the real progress is going to be made, the main network (Glasgow suburban, Fife, and mainlines to Aberdeen and Inverness) is

 

[haggishunter]

I do wonder why these threads always end up focusing on the relative edge cases such as Stranraer, Far North etc. They're not where the real progress is going to be made, the main network (Glasgow suburban, Fife, and mainlines to Aberdeen and Inverness) is

Guess these are more interesting than straight forward electrified mainlines? I had heard some chat about a potential new station for the Faslane submarine base which could include electrifying a section of the West Highland line to provide a much higher frequency of service.

Anyone have any info - did some googling but only found reference to it in minutes of hitrans such as https://hitrans.org.uk/documents/Mi...rd_Meeting_held_on_Friday_4_February_2022.pdf

More generally in terms of decarbonising in the short term could a way to reduce running diesel trains under power lines into city centres be to start more rural services away from the city centre terminals. If the diesel trains aren't traveling as far service frequencies could increase without more resources while reducing under powerline running.

Like West Highland services starting from Dumbarton or Inverness inter7city services going to/from Stirling. In the later case with specific electric connecting services to Edinburgh and Glasgow waiting, could it even be cross or same platform interchange for ease with luggage.

 

[najaB]

In the later case with specific electric connecting services to Edinburgh and Glasgow waiting, could it even be cross or same platform interchange for ease with luggage.

Every change - even cross platform - makes the journey by train take longer, less reliable and less attractive.

 

[snowball]

Press release with video. The soundtrack of the video mentions that two of the remaining five of the six new feeder stations will be at Thornton (as we expected) and Portobello. As Portobello is an existing feeder station it's perhaps surprising that they're counting the new works there as a new feeder station rather than among the nine existing sites that will see alterations.

For anyone who doesn't follow the Barrhead/EK thread, a planning application for a feeder site to be altered at Eglinton Street was mentioned there very recently (#880 and #883).

Transport Minister sees progress on feeder station upgrade programme

Scottish Government Transport Minister Jenny Gilruth visited the site of the first new feeder station to be commissioned as part of a £120m investment to boost the electricity supply into the railway network.

www.networkrailmediacentre.co.uk

Scottish Government Transport Minister Jenny Gilruth visited the site of the first new feeder station to be commissioned as part of a £120m investment to boost the electricity supply into the railway network.

The Ferguslie feeder station, which will connect to the network in October, was installed near Paisley supports the existing infrastructure as well as providing the additional electric power needed to support future decarbonisation of Scotland’s railway.

The investment will see six new feeder stations at strategic locations across the network and a further nine sites upgraded to increase the resilience and reliability of the infrastructure for the operation of electrically powered passenger and freight traffic.

As well as increasing the resilience of the existing network, the new connections to the national grid via the feeder stations will increase the overall capability of the 25kV electrified network.

This will enable future passenger and freight growth and reduce the railway’s carbon footprint by supporting the removal of diesel passenger trains from the network.

It’s all part of efforts to make Scotland’s railway greener in line with the Scottish Government’s commitment to decarbonise the passenger rail network by 2035.

 

[paul1609]

As such a length of OLE would only ever be charging batteries and operating one train it wouldn't need to be a 132kv/440kv grid fed 40MW-capable "proper" feeder station. A small SFC off the local DNO would be adequate, very much cheaper, and quicker to provide than a full-spec/capacity grid connection.

The only issue I can see is what if such a power feed goes offline? Will a train be able to get back north without picking up power?

The short section of OLE would still need to provide the power needed to power a typically 1MW train for 60miles (one way Stranraer to Ayr) in the layover time. I can't see the DNO having that sort of spare capacity to switch on and off in Stranraer, they certainly wouldn't in the majority of the South East away from the supergrid.

 

[gingertom]

The short section of OLE would still need to provide the power needed to power a typically 1MW train for 60miles (one way Stranraer to Ayr) in the layover time. I can't see the DNO having that sort of spare capacity to switch on and off in Stranraer, they certainly wouldn't in the majority of the South East away from the supergrid.

there's a wind farm just north of Glenluce. I think it would be pretty safe to assume it, or the grid it is connected to, could spare the power to charge a train's batteries for the return journey to Girvan.

 

[paul1609]

there's a wind farm just north of Glenluce. I think it would be pretty safe to assume it, or the grid it is connected to, could spare the power to charge a train's batteries for the return journey to Girvan.

The wind farms north of Glenluce are there because they can feed in to the grid connection to the Moyle Interconnector and the proposed second hvdc link to Northern Ireland. The 33kv pole route crosses the Stranraer line about a mile north of Barrhead Station. Does your “safe to assume" proposal assume that the bemus will pause for an hour at Barrhead to recharge or are you proposing that a 26 mile long 33Kv route be built (perhaps suspended above the tracks?) to allow the trains to recharge in Stranraer?