Battery power and bi-mode vs electrification

[Sorcerer]

I apologise if such a thread already exists covering this subject, but upon seeing threads about battery powered trains it prompted me to start a discussion as to whether or not things such as battery-powered trains are worth it in the long term compared to something more simple such as more electrification schemes. I also want to consider bi-mode trains because they are a more proven technology that I still think might be worth discussing. But the general question though is whether or not battery powered and bi-mode trains are a worthy long-term investment compared to further electrification of the network to enable more electric trains? Are the costs and benefits of one worth more than the other? In the short term I would imagine electrification may be more expensive, but once they are set up they tend to pay for themselves in the long term, especially overhead lines.

Meanwhile battery powered trains need good batteries as well as other components on board which naturally means more moving parts that would make each piece of rolling stock more expensive to build and maintain. Bi-mode trains have the same issue but they at least have the benefit of being able to run on overhead line networks and could possibly be converted in future to pure electric units provided it was no less beneficial than just buying new stock. But that said, I'm no expert on the subject matter, so therefore I'd like to get some opinions here as to whether or not bi-mode and/or battery-powered trains are a worthy long-term investment compared to electrification of non-electrified routes. I look forward to hearing people's thoughts on the matter.

 

[david1212]

Bi-mode needs to be defined for this thread.

If Bi-mode can be battery and electrified line be that overhead or third rail I see a long term future. Thinking primarily of overhead discontinuous electrification saves costs where limited clearance and the approaches to stations. For termini and through stations where trains terminate there would be electrification at the platforms for charging. For through stations where no or few trains terminate just contact wires or bars. So long as room for a pantograph and contact wire / bar bridges would not have to be rebuilt or the track lowered. As an example how much less might the cost be for electrification of the north Wales coast line or GW west of Exeter. Dependant on train range for the former electrification could end at Bangor and for the latter Truro or even further from Penzance.

 

[33101]

Meanwhile battery powered trains need good batteries as well as other components on board which naturally means more moving parts that would make each piece of rolling stock more expensive to build and maintain.

I'd be inclined to think that battery powered trains would actually have less moving parts, though battery capacity and durability (along with the tech needed to channel that power to the wheels and the required recharging infrastructure) may well be more expensive & less proven, at least in the near term.

 

[snowball]

Scotland intends to decarbonise its rail network by 2035, by which date diesel on internal passenger services should be eliminated. For a few of the remotest lines the current plan is to use hydrogen trains. For much of the rest of the network the plan is partial electrification and battery trains as a stepping-stone to full electrification. The final state is supposed to be reached by 2045.

 

[Doomotron]

I apologise if such a thread already exists covering this subject, but upon seeing threads about battery powered trains it prompted me to start a discussion as to whether or not things such as battery-powered trains are worth it in the long term compared to something more simple such as more electrification schemes. I also want to consider bi-mode trains because they are a more proven technology that I still think might be worth discussing. But the general question though is whether or not battery powered and bi-mode trains are a worthy long-term investment compared to further electrification of the network to enable more electric trains? Are the costs and benefits of one worth more than the other? In the short term I would imagine electrification may be more expensive, but once they are set up they tend to pay for themselves in the long term, especially overhead lines.

Meanwhile battery powered trains need good batteries as well as other components on board which naturally means more moving parts that would make each piece of rolling stock more expensive to build and maintain. Bi-mode trains have the same issue but they at least have the benefit of being able to run on overhead line networks and could possibly be converted in future to pure electric units provided it was no less beneficial than just buying new stock. But that said, I'm no expert on the subject matter, so therefore I'd like to get some opinions here as to whether or not bi-mode and/or battery-powered trains are a worthy long-term investment compared to electrification of non-electrified routes. I look forward to hearing people's thoughts on the matter.

Batteries degrade and are expensive - it is one of the overwhelming issues with electric cars and an issue made greater by the size of trains. It is no substitute for actual electrification, which is also expensive but is much more of a worthy investment.

 

[Ken H]

When you convert power there are always losses. So you convert your input power to electricity. Losses there. You may have to convert your 'raw' elecyricity to the right voltage and frequency with inverters and transformers. More losses. You then have to convert grid voltage to the electrification voltage with a transformer. More losses. Then in the train there are transformers and inverters to make the voltage/frequency for the motors. Lastly the motors change the electricity to rotational motion to make the wheels go round.
Shoving a battery and its associated control gear adds weight (remember Newton told us that force = mass times acceleration) and you get less out of a battery than you put in.
So for me, to avoud weight and battery losses, surely full electrification is the best way forward.
I dont think hydrogen can be considered zero carbon till a viable way of making it can be designed.

 

[Snow1964]

Battery trains are unlikely to be the way forward, realistically the batteries would probably need changing 3-5 times during a 40 year lifespan.

There is also some evidence from various European trials, that need about 40% of a route to be electrified anyway to charge them (the 40% is time under the wires, or on third rail, not distance), unless there is a separate fast charging system.

Bi-modes have advantages and disadvantages, the main advantage is ability to go beyond the electrified network and save cost of electrification, in some cases can also get trains into service faster than electrifying a route. However the disadvantages are many, including : extra cost; lots more maintenance; need to refuel with diesel; extra weight of carrying around the engine (both from energy usage, and track wear factor); lack of ability to use regeneraction in diesel mode; noisier than electric trains; harder to keep clean due to exhausts; vibration for passengers (which also lowers passengers ambience) etc.

Bi-modes have their place as a stop-gap solution, but make no sense as a long term solution. There is a much stronger case for a bit of low power alternative to allow the train to limp around a short electrification gap or breakage.

 

[100andthirty]

Battery electric bimodes will have their uses; for example, where it is disproportionately expensive to provide the OLE (a long low tunnel is an example). Some of the Cardiff Valleys electrification will have battery operated sections for this reason and a huge amount of system modelling had been applied to right size the batteries.

But the number of locations where "disproportionately expensive" is the reason have reduced significantly following work on the Great Western Electrification; two examples -
Cardiff: https://www.networkrailmediacentre....demolition-thanks-to-electric-resistant-paint, and
Steventon Bridge: https://www.railengineer.co.uk/steventon-bridge-overcoming-the-obstacle/

This learning is being applied to the Midland Main line electrification extensions.

 

[MattRat]

Bi modes are just an excuse not to invest in infrastructure. Lack of investment is precisely why the current railway is falling apart.

Electrification isn't hard, and third rail tech is getting to a point where it doesn't have to be dangerous at all. There is no excuse anymore, other than sheer laziness or malice against the railways, or both.

 

[CdBrux]

Bi modes are just an excuse not to invest in infrastructure. Lack of investment is precisely why the current railway is falling apart.

Electrification isn't hard, and third rail tech is getting to a point where it doesn't have to be dangerous at all. There is no excuse anymore, other than sheer laziness or malice against the railways, or both.

I disagree - bimodes can allow investment to be much better targeted and deliver benefits faster, ant least during an interim period which is probably at least 20 years

 

[mike57]

For the remote lines that are never going to be electrified in Scotland I do wonder at logic of doing away with diesel.

What percentage do the remote lines contribute to carbon emissions currently, very small I suspect.
I suspect there could be unforseen problems with Hydrogen, after all diesel has been refined for well over 100 years, and the technology is well understood
Hydrogen still requires electricity to be produced, so unless that is renewable or nuclear its still contributing emissions.
Battery power comes with its own set of problems, particularly surrounding life span and availability of the ingredients to make batteries.

To me the rational approach would be to electrify all the major routes, and leave the remaining 3 or 4 routes (Far North/Kyle, Fort Willliam/Mallaig, Oban and Stranraer) as diesel or Bi mode diesel electric depending upon through services to electrified sections.

 

[Trainbike46]

For the remote lines that are never going to be electrified in Scotland I do wonder at logic of doing away with diesel.

Ultimately GHG emissions need to get to zero, burning any fossil diesel is incompatible with that. Regarding the Far North, Kyle of Lochalsh and West Highland lines, the Scottish government has decided to move to zero emissions in 2035, probably (but not committed) by using hydrogen, which seems a sensible approach. If battery (or some other technology) improves to the extent to be a better option by say 2030, it could still be selected. The focus for now is on the busier routes (glasgow suburban routes, borders railway, fife circle, aberdeen etc.), as it rightly should be.

What percentage do the remote lines contribute to carbon emissions currently, very small I suspect.
I suspect there could be unforseen problems with Hydrogen, after all diesel has been refined for well over 100 years, and the technology is well understood
Hydrogen still requires electricity to be produced, so unless that is renewable or nuclear its still contributing emissions.
Battery power comes with its own set of problems, particularly surrounding life span and availability of the ingredients to make batteries.

The official government policy is for a zero carbon electricity network in 2035, so at that point all electrified rail lines, all battery trains and all hydrogen produced from electricity would also be zero carbon.

To me the rational approach would be to electrify all the major routes, and leave the remaining 3 or 4 routes (Far North/Kyle, Fort Willliam/Mallaig, Oban and Stranraer) as diesel or Bi mode diesel electric depending upon through services to electrified sections.

Clearly electrifying all the busy lines has priority in the short to medium term, but in the long term the railway does need to move fully zero emissions, and for lines such as the far north hydrogen, battery or some other technology will fit the bill.

== Doublepost prevention - post automatically merged: 25 Jul 2022 ==

Bi modes are just an excuse not to invest in infrastructure. Lack of investment is precisely why the current railway is falling apart.

Electrification isn't hard, and third rail tech is getting to a point where it doesn't have to be dangerous at all. There is no excuse anymore, other than sheer laziness or malice against the railways, or both.

While I mostly agree, I do think bimodes have a place in the short term: if new stock is needed for routes that haven't been electrified yet, it should be bimode to allow for easy conversion to full electric once the electrification catches up, kind of like GA did with order 755s for their (non-electrified) rural routes. The time for ordering new diesel-only trains passed a long time ago, as any new diesel delivered since about 2010 won't be able to be used for their full lifespan, unnecesarily driving up costs compared to bimode trains which do have a future

 

[mike57]

Ultimately GHG emissions need to get to zero, burning any fossil diesel is incompatible with that.

I agree GHG emissions need to be slashed, as for zero I wonder if that creates more trouble than it cures. If the electrification program reduced emissions to say 5% of their current value then to me that would be adequate, and a much more attainable target than zero. If globally GHG emissions were reduced to 5% of todays value by 2035 then my view is global warming would be halted. Hyrocarbon fuels will always have a place in very remote areas of the world, as they still offer the best kWhr per kg of any practical fuel. Developments may change that, but we cannot base decisions on unproven technology. Consider also the resources that go into building and maintaining rolling stock. Nothing is really 'zero carbon'.

 

[Mikey C]

The official government policy is for a zero carbon electricity network in 2035, so at that point all electrified rail lines, all battery trains and all hydrogen produced from electricity would also be zero carbon.

A worthy aim of course, but I'm slightly sceptical whether finances will allow this, especially with an independent Scotland having to juggle expenditure priorities.

I'm always a bit sceptical about ANY government promise with dates significantly in the future anyway.

 

[CdBrux]

Batteries degrade and are expensive - it is one of the overwhelming issues with electric cars and an issue made greater by the size of trains. It is no substitute for actual electrification, which is also expensive but is much more of a worthy investment.

I remember hearing or reading an article some years ago about electric mopeds in an Asian country. What happened to older, degraded, batteries was that they were replaced in the moped and added to battery banks that took power from the grid, especially overnight, and could then be used to charge up the mopeds in the day. It seems something vaguely similar is planned for the battery train trial on the Greenford branch. Could this be a possibility, clearly on a different scale? Ideally innovation in battery technology would eventually get to the point where this may be less needed.

 

[Domh245]

A worthy aim of course, but I'm slightly sceptical whether finances will allow this, especially with an independent Scotland having to juggle expenditure priorities.

I'm always a bit sceptical about ANY government promise with dates significantly in the future anyway.

Scotland (by and large) is a lot closer to 'net-zero' generation than anywhere else in Great Britain! Taking country carbon intensity forecast data from NationalGridESO, you can see that Scotland is consistently lower than either England or Wales, and does run at almost 0 on occasion. This snippet is only from the last week (+ next 2 days forecast) which I think has been comparatively still wind-wise



It is also worth pointing out that Shetland is running a trial producing hydrogen from it's ample renewable generation, at the moment it's locally used but could quite conceivably be shipped over to the mainland in the future (at lower cost than laying cables!)

 

[Ken H]

Scotland (by and large) is a lot closer to 'net-zero' generation than anywhere else in Great Britain! Taking country carbon intensity forecast data from NationalGridESO, you can see that Scotland is consistently lower than either England or Wales, and does run at almost 0 on occasion. This snippet is only from the last week (+ next 2 days forecast) which I think has been comparatively still wind-wise

View attachment 118209

It is also worth pointing out that Shetland is running a trial producing hydrogen from it's ample renewable generation, at the moment it's locally used but could quite conceivably be shipped over to the mainland in the future (at lower cost than laying cables!)

Is that generation or consumption? if Scotland is importing loads of electricity from the rest of the UK then a large part of scotlands consumption wont be green at all.

 

[cjmillsnun]

I apologise if such a thread already exists covering this subject, but upon seeing threads about battery powered trains it prompted me to start a discussion as to whether or not things such as battery-powered trains are worth it in the long term compared to something more simple such as more electrification schemes. I also want to consider bi-mode trains because they are a more proven technology that I still think might be worth discussing. But the general question though is whether or not battery powered and bi-mode trains are a worthy long-term investment compared to further electrification of the network to enable more electric trains? Are the costs and benefits of one worth more than the other? In the short term I would imagine electrification may be more expensive, but once they are set up they tend to pay for themselves in the long term, especially overhead lines.

Meanwhile battery powered trains need good batteries as well as other components on board which naturally means more moving parts that would make each piece of rolling stock more expensive to build and maintain. Bi-mode trains have the same issue but they at least have the benefit of being able to run on overhead line networks and could possibly be converted in future to pure electric units provided it was no less beneficial than just buying new stock. But that said, I'm no expert on the subject matter, so therefore I'd like to get some opinions here as to whether or not bi-mode and/or battery-powered trains are a worthy long-term investment compared to electrification of non-electrified routes. I look forward to hearing people's thoughts on the matter.

Not sure why more moving parts are needed in battery trains? They are basically electric trains. The traction motor would be the same. You’re adding a static converter and an inverter to the mix to allow charging and motor control. They are generally solid state. Battery technology has moved on a lot from the cell in your mobile phone.

== Doublepost prevention - post automatically merged: 25 Jul 2022 ==

Batteries degrade and are expensive - it is one of the overwhelming issues with electric cars and an issue made greater by the size of trains. It is no substitute for actual electrification, which is also expensive but is much more of a worthy investment.

EV batteries don’t degrade that much. There are EVs with plenty of miles on the clock that are on their original batteries that are just fine.

 

[Class83]

I agree GHG emissions need to be slashed, as for zero I wonder if that creates more trouble than it cures. If the electrification program reduced emissions to say 5% of their current value then to me that would be adequate, and a much more attainable target than zero. If globally GHG emissions were reduced to 5% of todays value by 2035 then my view is global warming would be halted. Hyrocarbon fuels will always have a place in very remote areas of the world, as they still offer the best kWhr per kg of any practical fuel. Developments may change that, but we cannot base decisions on unproven technology. Consider also the resources that go into building and maintaining rolling stock. Nothing is really 'zero carbon'.

Net zero is slightly different, planting enough trees to offset Diesel the West Highland, Kyle and Far North Lines is probably realistic given the low number of trains on the lines. Batteries make sense for short 'difficult' sections such as the Forth Bridge.

 

[Ken H]

Net zero is slightly different, planting enough trees to offset Diesel the West Highland, Kyle and Far North Lines is probably realistic given the low number of trains on the lines. Batteries make sense for short 'difficult' sections such as the Forth Bridge.

A couple of AA batteries is all you need to get over the Forth bridge. It isnt exactly far.
Seriously tho, maybe a flywheel or capacitors would be better for 'difficult' bits than batteries.

 

[Skie]

Stadler have put out some details of the battery 777’s:

While an IPEMU is driving on the electrified network, the batteries are charged via the third rail or by regenerative braking. The charging time is less than 15 minutes, and one battery is designed for more than 10,000 charge and discharge cycles. The transition from all-electric to IPEMU drive is smooth and not noticeable to passengers during the journey.

 

[Doomotron]

I remember hearing or reading an article some years ago about electric mopeds in an Asian country. What happened to older, degraded, batteries was that they were replaced in the moped and added to battery banks that took power from the grid, especially overnight, and could then be used to charge up the mopeds in the day. It seems something vaguely similar is planned for the battery train trial on the Greenford branch. Could this be a possibility, clearly on a different scale? Ideally innovation in battery technology would eventually get to the point where this may be less needed.

Maybe, but it doesn't solve the problem of changing the batteries once they're degraded. In an ideal world it wouldn't be an issue at all.

EV batteries don’t degrade that much. There are EVs with plenty of miles on the clock that are on their original batteries that are just fine.

However, trains are designed to last 30-40 years. There is no way they'll do that on a single set of batteries.

 

[SynthD]

I disagree - bimodes can allow investment to be much better targeted and deliver benefits faster, ant least during an interim period which is probably at least 20 years

I agree, but that’s a period far longer than election or funding cycles.

 

[Domh245]

Is that generation or consumption? if Scotland is importing loads of electricity from the rest of the UK then a large part of scotlands consumption wont be green at all.

Consumption! They also have figures for North & South Scotland (along with subnational regions for England and Wales) under the "regional" intensity forecasts. The info is also all available on the Carbon Intensity website. Currently Scotland is exporting it's electricity as well!

Maybe, but it doesn't solve the problem of changing the batteries once they're degraded. In an ideal world it wouldn't be an issue at all.

However, trains are designed to last 30-40 years. There is no way they'll do that on a single set of batteries.

Nor do most diesel trains end their life with the engines(/prime movers) they started with!!

 

[Bletchleyite]

Net zero is slightly different, planting enough trees to offset Diesel the West Highland, Kyle and Far North Lines is probably realistic given the low number of trains on the lines. Batteries make sense for short 'difficult' sections such as the Forth Bridge.

The answer here is more political than practical, i.e. it will be hard to justify keeping the rural railway open when Stagecoach start waving electric coaches around. The railway will be seen as a polluting anachronism and will be closed.

 

[Energy]

I remember hearing or reading an article some years ago about electric mopeds in an Asian country. What happened to older, degraded, batteries was that they were replaced in the moped and added to battery banks that took power from the grid, especially overnight, and could then be used to charge up the mopeds in the day. It seems something vaguely similar is planned for the battery train trial on the Greenford branch. Could this be a possibility, clearly on a different scale? Ideally innovation in battery technology would eventually get to the point where this may be less needed.

Its not uncommon, Gridserve are using it on some of their EV chargers and Vivarail are proposing it. Effectively a container full of batteries charges from the grid and can then fast charge a train or car, usually used due to grid constraints.

Nor do most diesel trains end their life with the engines(/prime movers) they started with!!

Indeed, the 168s are going a new engine trial right now.

Engines also require much more maintenance than a battery.

Net zero is slightly different, planting enough trees to offset Diesel the West Highland, Kyle and Far North Lines is probably realistic given the low number of trains on the lines. Batteries make sense for short 'difficult' sections such as the Forth Bridge.

Its not impossible, by road Inverness to Thurso is 110 miles, Trainline claims is 81 miles by rail though I don't believe it.

Stadler currently sell the Flirt Akku on their website with a 150km (93 miles) range, though they've achieved 224km (139 miles) with it in freezing conditions. In a few years, especially with part of the lower end being electrified at some point, it could be done with a recharge at Thurso/Wick.

 

[paul1609]

Its not uncommon, Gridserve are using it on some of their EV chargers and Vivarail are proposing it. Effectively a container full of batteries charges from the grid and can then fast charge a train or car, usually used due to grid constraints.

Indeed, the 168s are going a new engine trial right now.

Engines also require much more maintenance than a battery.

Its not impossible, by road Inverness to Thurso is 110 miles, Trainline claims is 81 miles by rail though I don't believe it.

Stadler currently sell the Flirt Akku on their website with a 150km (93 miles) range, though they've achieved 224km (139 miles) with it in freezing conditions. In a few years, especially with part of the lower end being electrified at some point, it could be done with a recharge at Thurso/Wick.

Inverness to Thurso by rail is 153 miles 68 chains

 

[Bald Rick]

whether or not things such as battery-powered trains are worth it in the long term compared to something more simple such as more electrification schemes.

I think you are starting off the argument with a potentially flawed statement. Some electrification schemes are anything but simple, whereas a battery train can be (indeed is) relatively simple.

Are the costs and benefits of one worth more than the other?

well that’s the big question, and the answer is “it depends”.

for high intensity, high speed or high tonnage routes, electrification is the most cost effective answer.

for low intensity / low speed / low tonnage routes battery trains will be the most cost effective answer


It is going to be interesting to see where the crossover point is.

 

[Wyrleybart]

For the remote lines that are never going to be electrified in Scotland I do wonder at logic of doing away with diesel.

I believe it is law that diesel has to be binned, just like coal has been

What percentage do the remote lines contribute to carbon emissions currently, very small I suspect.
I suspect there could be unforseen problems with Hydrogen, after all diesel has been refined for well over 100 years, and the technology is well understood
Hydrogen still requires electricity to be produced, so unless that is renewable or nuclear its still contributing emissions.
Battery power comes with its own set of problems, particularly surrounding life span and availability of the ingredients to make batteries.

To me the rational approach would be to electrify all the major routes, and leave the remaining 3 or 4 routes (Far North/Kyle, Fort Willliam/Mallaig, Oban and Stranraer) as diesel or Bi mode diesel electric depending upon through services to electrified sections.

 

[Bald Rick]

I believe it is law that diesel has to be binned, just like coal has been

neither are law.