Rail decarbonisation: What are the solutions?

[507021]

With the early Sprinter fleets now rapidly reaching the end of their service life, I think it's imperative that the powers that be start looking at replacing them as soon as possible. But with all of the various net zero carbon emissions targets which are becoming increasingly common, is the easiest and most obvious solution to replacing them, bespoke off the shelf diesel units, necessarily the best solution?

While I think hydrogen will have a big part to play in helping the railway network become carbon neutral, at the moment I think viable, large scale deployment of HMUs is several years away at least. Dual mode units could also be a possible solution in the right application, but is ordering them to run them on diesel until there's enough wires really a sensible idea? I'm not so sure.

I think there's been some really interesting ideas shared on this subject in various topics, and I'd be interested to hear if anyone else has any thoughts.

 

[Bletchleyite]

On the other thread we touched on biodiesel. This involves planting rather a lot of rapeseed, so is not a viable replacement for all diesel consumption, i.e. cars + buses + lorries + trains. But as cars and at least urban buses are going electric, that only leaves coaches, lorries and rail that might need it, a rather smaller amount. So I think biodiesel could certainly contribute. Engines would need to be modified to run on 100% biodiesel, but that is hardly impossible.

The downside is that even though biodiesel is (in itself) carbon-neutral* it does still kick out NOx, SO2, particulates etc (the "point of use" problem), so it's still not OK to be burning it in cities or getting passengers' noses full of it in places like New St and Manchester Victoria. So I'd say that any such units built new should be bi-modes with a small battery capacity such that the engines can be turned off when in cities and enclosed stations. If there is a need to recharge and the train doesn't run under the wires, you can just run the engines a little faster when outside the cities and charge then.

This concept is not entirely pie in the sky - it is already fitted to the TfW 230s.

* To the extent anything is; even if the electricity grid was 100% renewable/nuclear you've still got the effects of making batteries.

 

[greatvoyager]

I think the biggest issue will be what replaces diesel as a fuel. There are trials with hydrogen and batteries, but is there another option?

 

[birchesgreen]

A 20+ year rolling programme of electrification.

 

[43096]

A 20+ year rolling programme of electrification.

Is the right answer.

 

[221101 Voyager]

A 20+ year rolling programme of electrification.

A good start would be to electrify all the mainlines so complete the MML and also maybe the Chiltern?

Maybe also the Cross country routes could do with electrification to get rid of the diesels on there?

Are they any plans of any kind to electrify any of these lines at present?

 

[adc82140]

I think the first priority should be to find a solution to the "diesel islands" on the network, where there is the onward effect of a large amount of under the wires (or over the conductor rail) diesel running. Whether that's bi-mode, battery or another option I don't know.

 

[anthony263]

Finish the missing bits of the Gwml inuding swansea as well as linking the gwml electrification to other electrified parts of the UK rail network.

 

[Starmill]

On the other thread we touched on biodiesel. This involves planting rather a lot of rapeseed, so is not a viable replacement for all diesel consumption, i.e. cars + buses + lorries + trains. But as cars and at least urban buses are going electric, that only leaves coaches, lorries and rail that might need it, a rather smaller amount. So I think biodiesel could certainly contribute. Engines would need to be modified to run on 100% biodiesel, but that is hardly impossible.

The downside is that even though biodiesel is (in itself) carbon-neutral* it does still kick out NOx, SO2, particulates etc (the "point of use" problem), so it's still not OK to be burning it in cities or getting passengers' noses full of it in places like New St and Manchester Victoria. So I'd say that any such units built new should be bi-modes with a small battery capacity such that the engines can be turned off when in cities and enclosed stations. If there is a need to recharge and the train doesn't run under the wires, you can just run the engines a little faster when outside the cities and charge then.

This concept is not entirely pie in the sky - it is already fitted to the TfW 230s.

* To the extent anything is; even if the electricity grid was 100% renewable/nuclear you've still got the effects of making batteries.

Biodiesel has been tried before, in the voyager fleet in a specific mixture. However, the goal is net zero, which isn't easy here because the crop will need viable land and water, plus energy used in processing and transport. Those emissions will need capturing somehow. Also, is there actually enough agricultural land around, thinking about Great Britain here, to grow ourselves a reliable supply of biofuel? Bearing in mind that we need much this land to grow food, and much of what's left we need to use to use for carbon capture or renewable energy.

 

[Rhydgaled]

While I think hydrogen will have a big part to play in helping the railway network become carbon neutral, at the moment I think viable, large scale deployment of HMUs is several years away at least. Dual mode units could also be a possible solution in the right application, but is ordering them to run them on diesel until there's enough wires really a sensible idea? I'm not so sure.

It's a difficult one certainly. The extra weight of a bi-mode unit will hurt fuel economy so you don't really want to be using them on routes with little or no electrification. But, as others have said, a rolling programme of electrification is needed and you need a fleet that supports that. Converting a diesel mechanical unit to a bi-mode or EMU seems to be a major challange so would be a hinderance to any electrification business case - perhaps the answer is to design the new fleet as bi-mode but leave the pantograph and transformer off until they are needed.

I think the biggest issue will be what replaces diesel as a fuel. There are trials with hydrogen and batteries, but is there another option?

Network Rail has attempted to answer the question in the title with their Traction Decarbonisation Network Strategy. The solutions it presents are electrification (for the vast majority of the network), batteries and hydrogen. There is possibly a transition role to play for things like LPG (or was it natural gas - I forget exactly but I think trials were underway with a class 180?) and bio-diesel but the endpoint we need to be aiming at is probably pretty much what Network Rail have in the TDNS.

A 20+ year rolling programme of electrification.

A good start would be to electrify all the mainlines so complete the MML and also maybe the Chiltern?

Maybe also the Cross country routes could do with electrification to get rid of the diesels on there?

Are they any plans of any kind to electrify any of these lines at present?

Network Rail is recommending a widespread rolling programme of electrification in the TDNS; but the political will to decarbonise rail still seems to be lacking. That needs to change.

As for starting with the mainlines, the MML at least doesn't seem to be much help with the problem in the first post regarding Sprinter replacement. As such, I think the first priority should be TPE - releasing 185s to replace 195s which in turn can be used to get rid of the 150/1s. I think a new build of bi-mode (or DEMU with passive provision for convertion) 100mph units should be persued to replace classes 155-159 - these should have single-width doors like the units they are replacing but not necessarily at the vehicle ends (the class 444s are a good template).

Biodiesel is little more than a fudge that lets us figure out what to do longer term - it 'solves' the CO2 problem, but doesn't solve many other problems

It doesn't even solve the CO2 problem. It probably reduces the CO2 problem, but the land to grow it has to come from somewhere and ultimately that probably results in deforestation somewhere.

 

[507021]

A 20+ year rolling programme of electrification.

Is absolutely the best way forward, IMO. If only there was the ambition and competence to devise and then see through such a scheme.

I think the biggest issue will be what replaces diesel as a fuel. There are trials with hydrogen and batteries, but is there another option?

I think biodiesel would be a decent stop gap solution while a sustainable long term strategy is devised. Although again, there doesn't seem to be much ambition to actually sit down and devise a robust plan for sustainable rail decarbonisation. It's alright setting net zero targets, but there's not really been much in the way of explaining how these might actually be achieved.

It doesn't even solve the CO2 problem. It probably reduces the CO2 problem, but the land to grow it has to come from somewhere and ultimately that probably results in deforestation somewhere.

Surely a reduction is better than not doing anything at all? We've got to start somewhere.

It's a difficult one certainly. The extra weight of a bi-mode unit will hurt fuel economy so you don't really want to be using them on routes with little or no electrification. But, as others have said, a rolling programme of electrification is needed and you need a fleet that supports that. Converting a diesel mechanical unit to a bi-mode or EMU seems to be a major challange so would be a hinderance to any electrification business case - perhaps the answer is to design the new fleet as bi-mode but leave the pantograph and transformer off until they are needed.

That's why I don't think dual modes are going to be a good solution. They're expensive and the fact is Northern and GWR wouldn't get the best out of them, with many of their respective routes operated by 150s being entirely unelectrified. It just seems counter productive to me.

I still think it'd be possible to design a modular DMU/DEMU which the provision to convert it to an EMU in the future.

 

[quantinghome]

A 20+ year rolling programme of electrification.

Correct.

Hydrogen and batteries work at the margins. But they will be niche.

 

[Milo T.K]

A 20+ year rolling programme of electrification.

Whilst that may be the way forward. It may not be practical in a few places with low areas. For a measure where electrification cannot be done id say hydrogen since 1. It does not die after a few years like batteries do. 2, it's more feasible since batteries have rare earth metals which (probably) won't be economical(not counting electrification). 3, hydrogen probably will have more range.

 

[AM9]

Correct.

Hydrogen and batteries work at the margins. But they will be niche.

So in view of those being niche, mainstream requirements of all new rolling stock should have provision for the following:

final drives to the wheels should be electric motors. Contemporary electric traction motors use lightweight three-phase induction motors, (some with permanent magnets) that are suitable for regenerative operating. That energy can be re-used by the supply system or to charge on-board batteries. Even the worst use, i.e. electro-rheostatic braking has maintenance benefits.​

power collection from OLE (pantograph well) with space for a modern compact transformer, it is assumed that a DC bus and collector shoes could also be added without much disruption.​

everything else depends on non-electric prime mover choices, provided thay all have a coupled generator to feed the traction system. There really is no place for anything that compels the railway to continue emitting CO2 and SO2/NOX for 40 years after delivery.

 

[Domh245]

Whilst that may be the way forward. It may not be practical in a few places with low areas. For a measure where electrification cannot be done id say hydrogen since 1. It does not die after a few years like batteries do. 2, it's more feasible since batteries have rare earth metals which (probably) won't be economical(not counting electrification). 3, hydrogen probably will have more range.

Seeing as hydrogen units are really battery EMUs but with some battery space sacrificed for the hydrogen tanks and fuel cells, your first two points still apply to them (though by most accounts, the 'batteries lose range' argument seems to be overdone in this context). The only advantage that hydrogen has over batteries is range - and even then with the cost of hydrogen generation and distribution equipment you may still be better off with a battery EMU and some strategically placed 'quick charge' OLE

 

[Rhydgaled]

Is absolutely the best way forward, IMO. If only there was the ambition and competence to devise and then see through such a scheme.

[snip]Although again, there doesn't seem to be much ambition to actually sit down and devise a robust plan for sustainable rail decarbonisation.

There is. Network Rail have sat down and devised a plan for rail decarbonisation. I believe they are now working on the sequencing for a rolling programme, but they have already published the first stage report which specifies which routes should ultimately be battery operated, which ones hydrogen and which ones electrified. The problem is the lack of interest in Westminster.

Whilst that may be the way forward. It may not be practical in a few places with low areas. For a measure where electrification cannot be done id say hydrogen since 1. It does not die after a few years like batteries do. 2, it's more feasible since batteries have rare earth metals which (probably) won't be economical(not counting electrification). 3, hydrogen probably will have more range.

Hydrogen and batteries work at the margins. But they will be niche.

Which is exactly what the Network Rail report recommends; widespread electrification with battery operation for most of the marginal routes and hydrogen where a longer off-wire range is required. The report is called the Traction Decarbonisation Network Strategy (TDNS) and can be found here (type page 85 into your PDF reader to see the map - the page number shown on the page is 79 but the PDF presumably includes some un-numbered pages).

Surely a reduction is better than not doing anything at all? We've got to start somewhere.

Yes, it's probably better to convert existing DMUs to run on bio-diesel (or something else like whatever gas it was they are trialing in a 180) than to keep using diesel in them, but if we are to have a rolling programme of electrification we will also need to be steadily reducing the number of units we have that cannot make use of electrification. Building something that will run solely on bio-diesel for the next 35 years is not going to help the case for a rolling programme of electrification.

I still think it'd be possible to design a modular DMU/DEMU which the provision to convert it to an EMU in the future.

How would that be different from a bi-mode with the transformer and pantograph left off initially?

So in view of those being niche, mainstream requirements of all new rolling stock should have provision for the following:

final drives to the wheels should be electric motors. Contemporary electric traction motors use lightweight three-phase induction motors, (some with permanent magnets) that are suitable for regenerative operating. That energy can be re-used by the supply system or to charge on-board batteries. Even the worst use, i.e. electro-rheostatic braking has maintenance benefits.​

power collection from OLE (pantograph well) with space for a modern compact transformer, it is assumed that a DC bus and collector shoes could also be added without much disruption.​

everything else depends on non-electric prime mover choices, provided thay all have a coupled generator to feed the traction system. There really is no place for anything that compels the railway to continue emitting CO2 and SO2/NOX for 40 years after delivery.

Exactly; the TDNS report advises against procurement of new diesel-only units (although sadly with weasel words).

 

[Purple Orange]

As far as decarbonsatuon goes, I'd say build more light rail metro in our cities. After walking and cycling, light rail trams is the most environmentally friendly mode of transport.

That also means converting current heavy rail lines where possible, given the metro frequency of the light rail lines brings with it a big increase in passenger usage compared to their heavy rail counterparts. The alternative for heavy rail is to give alternative similar frequency but there needs to be the infrastructure to terminate the trains somewhere.

 

[Mikey C]

The important thing is to electrify the routes that can remove most DMU mileage first, whether whole "systems" such as the Chiltern network up to Moor Street, then continuing through Birmingham Snow Hill, or branch lines which can eliminate a lot of diesel under wires working in urban areas like Birmingham, Manchester and Leeds.

 

[DerekC]

The important thing is to electrify the routes that can remove most DMU mileage first, whether whole "systems" such as the Chiltern network up to Moor Street, then continuing through Birmingham Snow Hill, or branch lines which can eliminate a lot of diesel under wires working in urban areas like Birmingham, Manchester and Leeds.

I think that's a good principle. Put it together with a rolling stock strategy as proposed by @Rhydgaled and @507021, where all DMU replacements have on-wire and off-wire capability (whether at this stage that's diesel/OLE or battery/OLE or (in the future) hydrogen/battery/OLE) and you have the makings of a plan. The difficult bit is making the business cases add up at current OLE cost - but if government is serious about decarbonisation it should commit to a rolling programme of X000 km/year, when the only question becomes which routes to do next. RIA's Electrification Cost Challenge has shown the way to get the costs down.

Unfortunately DfT is now obsessed with road and has shown again and again that it just doesn't do joined up! I will be interested (to say the least) to read the DfT Transport Decarbonisation Plan when that comes out "in Spring 2021".

 

[Swanley 59]

Another vote for a rolling programme of electrification.

In the meantime, given the limitations of existing hydrogen and battery technology, has the option of Compressed Natural Gas (CNG) been explored as an alternative to diesel? The bus industry has made great strides with CNG engines. The CNG buses in Sunderland are markedly quieter than their diesel counterparts, and I believe emissions are significantly reduced.

 

[quantinghome]

Another vote for a rolling programme of electrification.

In the meantime, given the limitations of existing hydrogen and battery technology, has the option of Compressed Natural Gas (CNG) been explored as an alternative to diesel? The bus industry has made great strides with CNG engines. The CNG buses in Sunderland are markedly quieter than their diesel counterparts, and I believe emissions are significantly reduced.

Somewhat reduced, but will still emit significant CO2 from the exhaust.

 

[507021]

There is. Network Rail have sat down and devised a plan for rail decarbonisation. I believe they are now working on the sequencing for a rolling programme, but they have already published the first stage report which specifies which routes should ultimately be battery operated, which ones hydrogen and which ones electrified. The problem is the lack of interest in Westminster.

Fair enough, I wasn't aware such a plan existed. Let's hope it can actually be implemented in a competent, timely and cost effective manner.

Yes, it's probably better to convert existing DMUs to run on bio-diesel (or something else like whatever gas it was they are trialing in a 180) than to keep using diesel in them, but if we are to have a rolling programme of electrification we will also need to be steadily reducing the number of units we have that cannot make use of electrification. Building something that will run solely on bio-diesel for the next 35 years is not going to help the case for a rolling programme of electrification.

The fact is, there will be a large number of routes which simply aren't going to justify the cost of electrification for various reasons. It's very probable we'll need the 158s/159s for at least another ten to fifteen years, the Turbostars for another twenty and the 185s, 195s, 196s and 197s for the full length of their designed service life. To state a specific timeframe for the latter, I expect it'll be the mid-to-late 2050s before the Civity diesel units are withdrawn. However, by then I'll be in my 60s and would like to think we'll have sufficient electrification and know whether hydrogen or another alternative fuel source is a viable and sustainable alternative for routes which can't be electrified.

How would that be different from a bi-mode with the transformer and pantograph left off initially?

That wouldn't be a dual mode unit though, it'd be a DEMU with provision to convert to dual mode or EMU built into the design. That's exactly what TfW Rail's 769s are.

 

[Mikey C]

Fair enough, I wasn't aware such a plan existed. Let's hope it can actually be implemented in a competent, timely and cost effective manner.



The fact is, there will be a large number of routes which simply aren't going to justify the cost of electrification for various reasons. It's very probable we'll need the 158s/159s for at least another ten to fifteen years, the Turbostars for another twenty and the 185s, 195s, 196s and 197s for the full length of their designed service life. To state a specific timeframe for the latter, I expect it'll be the mid-to-late 2050s before the Civity diesel units are withdrawn. However, by then I'll be in my 60s and would like to think we'll have sufficient electrification and know whether hydrogen or another alternative fuel source is a viable and sustainable alternative for routes which can't be electrified.



That wouldn't be a dual mode unit though, it'd be a DEMU with provision to convert to dual mode or EMU built into the design. That's exactly what TfW Rail's 769s are.

By 2050 the CAFs will have fallen apart anyway, thus forcing more electrification

 

[Ianno87]

Was thinking about the earlier.

A small improvement would be minimising "diesel under the wires" unless there isn't a practical alternative.

For example:
-CrossCountry Birmingham-Stansted cut back to Cambridge (onward service provided by Greater Anglia)
-CrossCountry not North of Leeds/York (covered by TPE/LNER bi-modes instead)
-Northern Barrow/Windermere as shuttles only (or bi-mode stock)

That sort of thing.

(For example, I would keep XC to/from Manchester as Voyagers or future bi-modes due to the complexity of splitting the paths at Birmingham)

 

[AverageTD]

The important thing is to electrify the routes that can remove most DMU mileage first, whether whole "systems" such as the Chiltern network up to Moor Street, then continuing through Birmingham Snow Hill, or branch lines which can eliminate a lot of diesel under wires working in urban areas like Birmingham, Manchester and Leeds.

Absolutely, I also think common routes which are majority electric with diesel sections at either end, to alleviate the need for bi-mode trains or diesels under the wires. Chester to Crewe, Newark to Lincoln etc

 

[zwk500]

The important thing is to electrify the routes that can remove most DMU mileage first, whether whole "systems" such as the Chiltern network up to Moor Street, then continuing through Birmingham Snow Hill, or branch lines which can eliminate a lot of diesel under wires working in urban areas like Birmingham, Manchester and Leeds.

The biggest gains for decarbonisation would be frequent stop-start routes, so the Moor St/Snow Hill lines would be a fantastic place to start.

 

[507021]

By 2050 the CAFs will have fallen apart anyway, thus forcing more electrification

That could also end up being a possibility!

 

[Mordac]

By 2050 the CAFs will have fallen apart anyway, thus forcing more electrification

They're falling apart already!

 

[xotGD]

Using "drop in" biofuels means that you can operate existing train fleets without modifications.

Biomass gasification followed by Fischer Tropsch Synthesis. Gives you diesel fuel with very high cetane and essentially zero sulphur. Incorporate carbon capture and you have carbon negative fuel.

This is what the aviation sector is looking at to produce 'green' Jet-A1.

 

[AM9]

Using "drop in" biofuels means that you can operate existing train fleets without modifications.

Biomass gasification followed by Fischer Tropsch Synthesis. Gives you diesel fuel with very high cetane and essentially zero sulphur. Incorporate carbon capture and you have carbon negative fuel.

This is what the aviation sector is looking at to produce 'green' Jet-A1.

It sounds like a lot of hardware and subsequent processing just to be able to continue running what are now diesel vehicles. That would only be justifiable if they were used on diagrams where there was no running under the wires. Just how much primary energy is required to produce the fuel?