Why we shouldn't electrify more of the UK

[Kneedown]

I maintain however that service improvements themselves can be more important than electrification if one is forced to choose.

Electrification alone brings service improvements despite what the sceptics say, but for environmental reasons alone it is worth pursuing. Diesel is out of favour, and rightly so due to emmisions and health concerns. Battery technology still needs frequent and lengthy recharging, and although hydrogen is being tested, there are still questions over safety, supply, storage and performance.

 

[hexagon789]

Electrification alone brings service improvements despite what the sceptics say, but for environmental reasons alone it is worth pursuing. Diesel is out of favour, and rightly so due to emmisions and health concerns. Battery technology still needs frequent and lengthy recharging, and although hydrogen is being tested, there are still questions over safety, supply, storage and performance.

Oh I'm not sceptical of its benefits - but I would still rather have no electrification and say an increase to 4tph on a route than electrification and no change in frequency. To me frequency, at least on busier routes (which are generally more ripe for electrification any way), is more important , that's what I'm driving at.

 

[GRALISTAIR]

Frequency is good but electrification helps frequency. Faster acceleration and all that good stuff.

 

[Pigeon]

Electrification as it is currently carried out has a bunch of problems...

The overall conversion efficiency from chemical energy of fuel to mechanical output from the wheels is not a lot different whether you use a remote generating plant and transmit the electricity, or a local plant and transmit the fuel. You get some benefit from remote generation using nuclear or renewable sources, but since most of our electricity still does come from fossil fuel (all this crowing about "no coal" days but they never mention that the replacement for all those closed coal power stations was gas ones...) and since railways use only a minor percentage of the fossil fuel used for transport, it's nothing like as much of a benefit as it's made out to be.

It may even be a negative benefit, since not having to carry the generator about with you removes a major limitation on the power output of the train, and people are often tempted to specify grossly overpowered traction as a result. The additional power consumption wipes out any gain you might otherwise have got from part of the supply being nuclear or renewable. This is particularly the case when the temptation to go for excessive speed also comes into it - energy consumption for a given journey varies as the square of the speed (and power consumption as the cube), but the reduction in journey time is often nugatory especially when you consider the total time end-to-end as opposed to just that part of it spent on a moving train.

It costs an absolute packet, not only for the kit itself but for the reconstruction of the whole route with increased clearances. The money would often be better spent on getting rid of speed restrictions, improving junctions and flexibility, making stations pleasant places to wait, etc. etc. In the case of reopening a closed route, to insist on electrification may make the project so expensive that instead of a non-electrified line we just don't get the line at all, and that's no use to anyone.

It's kind of daft for minor routes that see little traffic, especially those that are in remote and inhospitable places (like the Highlands) which add harsh weather and difficult access to the extra maintenance the wiring needs anyway.

Diesel haulage is still needed for trains that run over routes which are only partly electrified. Particularly awkward for freight, with the kind of twiddly bits at the ends, perhaps even on private land, that would need to be wired. Or where the wires would get in the way of loading.

It is prone to catastrophic failures which take out an entire route instead of just one track, and which cause damage extending over several miles.

It is ugly as arseholes.

I'm not sure what the current state of play is with regard to going past those endless masts all day kzhoonk kzhoonk kzhoonk doing the driver's head in, but they certainly are hypnotic and it must be of at least some significance.

Non-diesel alternatives: on-board rechargeable energy storage works for short or shortish passenger branches - flywheels for the very short ones, batteries for not so short ones, especially if someone has the sense to use separate locomotives and coaches so the coaches can be hauled by one loco while the others recharge. Though there is still a question about the sustainability of battery manufacture.

For longer distances, it helps to drop the insistence on overhead wiring. Using a 4-rail system on something like +/-1.5kV with the feed not through the rails themselves but through large-section aluminium busbars alongside the track cross-linked to the rails at frequent intervals, the losses can be brought down to the same level as with 25kV overhead. It is not a safety problem - accidents to railway staff from overhead and live rail happen at about the same rate, and the increased voltage is not increased enough to affect the danger level. Overhead clearances do not need to be increased, installation is easier, maintenance is easier, high winds don't kill it, damage usually affects only one line, and it's unobtrusive.

 

[AM9]

Electrification as it is currently carried out has a bunch of problems...

The overall conversion efficiency from chemical energy of fuel to mechanical output from the wheels is not a lot different whether you use a remote generating plant and transmit the electricity, or a local plant and transmit the fuel. You get some benefit from remote generation using nuclear or renewable sources, but since most of our electricity still does come from fossil fuel (all this crowing about "no coal" days but they never mention that the replacement for all those closed coal power stations was gas ones...) and since railways use only a minor percentage of the fossil fuel used for transport, it's nothing like as much of a benefit as it's made out to be.

The current trend for removing fossil fuels across the world will accelerate and it's not so that some difficult uses can be perpetuated. Rail will be seen as just another polluter. Added to the the particulate contamination that diesel carries into areas of mass population, it will not be tolerated so remote well controlled generation (even using a small amount of fossil fuels) will be the only option available except to the military and emergency services.

It may even be a negative benefit, since not having to carry the generator about with you removes a major limitation on the power output of the train, and people are often tempted to specify grossly overpowered traction as a result. The additional power consumption wipes out any gain you might otherwise have got from part of the supply being nuclear or renewable. This is particularly the case when the temptation to go for excessive speed also comes into it - energy consumption for a given journey varies as the square of the speed (and power consumption as the cube), but the reduction in journey time is often nugatory especially when you consider the total time end-to-end as opposed to just that part of it spent on a moving train.

The low rolling resistance, minimal air resistance, controllable and predictable speeds and the ability to feed regenerated energy back into the supply all effectively negate the impact of higher available power per se. On the subject of absolute speed, (in the UK), for over two decades, most of the rail journeys at the highest speeds (125mph) were diesel hauled (HST), - it's only recently that high speed electric services have been increased above that level. But, once again, the cruising at higher speeds uses relatively little extra power as a means to provide higher capacity transport whilst at the same time, actually drawing custom from the high polluter modes, i.e. road and air.

It costs an absolute packet, not only for the kit itself but for the reconstruction of the whole route with increased clearances. The money would often be better spent on getting rid of speed restrictions, improving junctions and flexibility, making stations pleasant places to wait, etc. etc. In the case of reopening a closed route, to insist on electrification may make the project so expensive that instead of a non-electrified line we just don't get the line at all, and that's no use to anyone.

Removing the pollution does make not only stations more pleasant, but also the immediate environment along the whole route. The capital cost of electrification is a one-time expenditure, and the associated civil engineering has a life exceeding 50 years, - often 120 years. In those periods, the extended life of rolling stock, and the running cost of the installation makes the difference much lower and sometimes actually cheaper that perpetuating the pollution (and tarting up stations as an attempt to mitigate that pollution).

It's kind of daft for minor routes that see little traffic, especially those that are in remote and inhospitable places (like the Highlands) which add harsh weather and difficult access to the extra maintenance the wiring needs anyway.

OLE appropriate for the role has a maintenance requirement that can easily be accommodated even in remote inhospitable areas. OLE railways run through the Alps, in Arctic zones in Scandinavia and across Siberia. What makes you thing that the UK is so hostile that it can't be viable.

Diesel haulage is still needed for trains that run over routes which are only partly electrified. Particularly awkward for freight, with the kind of twiddly bits at the ends, perhaps even on private land, that would need to be wired. Or where the wires would get in the way of loading.

They seem to manage on the European mainland where much more freight is carried than in the UK.

It is prone to catastrophic failures which take out an entire route instead of just one track, and which cause damage extending over several miles.

That's true for older low-cost OLE, - thankfully, the industry in the UK has at last understood that you get what you pay for and the latest schemes, getting rid of daft headspans will much reduce the damage to wiring on adjacent tracks. With a busy mainline, any breakdown can cause a long line of queueing trains so there's not that much difference anyway.

It is ugly as arseholes.

Not worth commenting on what is just a personal opinion.

I'm not sure what the current state of play is with regard to going past those endless masts all day kzhoonk kzhoonk kzhoonk doing the driver's head in, but they certainly are hypnotic and it must be of at least some significance.

I've never heard any comment at all about that. Maybe a driver here could offer an informed opinion of the visual compared with the diesel drone and pollution along the thline, througn tunnels and sitting in stations.

Non-diesel alternatives: on-board rechargeable energy storage works for short or shortish passenger branches - flywheels for the very short ones, batteries for not so short ones, especially if someone has the sense to use separate locomotives and coaches so the coaches can be hauled by one loco while the others recharge. Though there is still a question about the sustainability of battery manufacture.

Battery manufacture is just another consumer of raw materials with some re-use. Other than for limited 'add-on' electric train operation, it's real use should be to prevent all running diesel under wires.

For longer distances, it helps to drop the insistence on overhead wiring. Using a 4-rail system on something like +/-1.5kV with the feed not through the rails themselves but through large-section aluminium busbars alongside the track cross-linked to the rails at frequent intervals, the losses can be brought down to the same level as with 25kV overhead. It is not a safety problem - accidents to railway staff from overhead and live rail happen at about the same rate, and the increased voltage is not increased enough to affect the danger level. Overhead clearances do not need to be increased, installation is easier, maintenance is easier, high winds don't kill it, damage usually affects only one line, and it's unobtrusive.

In a modern risk-aware society, accessible exposed high-voltage conductors will progressively eradicated, and no new schemes will be entertained, even as a proposal.

 

[Indigo Soup]

There is something of a national security argument, in that electrification means that the continued functioning of the rail network requires an operational power supply network. Diesel or steam haulage will still work as long as you can get fuel (and water) to the locomotives. In practice, the Ministry of Defence wasn't concerned about comprehensive electrification proposals as even in the most extravagant schemes there would remain enough diesel locomotives to work essential traffic.

 

[ijmad]

Battery trains, with 3rd rail at stations to provide a top-up charge will soon be very feasible.

Has anyone explored live running rail electrification? If the running rails were electrified and the wheels acted as the pickup shoes, it would negate many of the challenges of third rail in icy conditions.

I am not sure battery tech will be good enough to allow for stations to be the only charging sites and long distance services any time soon, you simply can't deliver that kind of energy quickly enough during a stop. A passenger train consumes around 3.5 kWh per carriage-mile, so a 12 coach London to Edinburgh service will need 16,800 kWh, or around 1200 kWh delivered at each of the 14 stops (ignoring the fact they are different distances apart). A Tesla's battery pack is 85kWh, so you'd need 15 of these at the very least for a full train journey. Not actually that impractical if perhaps, you had a couple under the floor of each coach, but to charge that in the few minutes you stop at a station is well beyond current technology. I also think doing that at a station might be a bad idea, given you want passengers as far away from electricity as is reasonably possible.

That said, I do think batteries could cut the costs of electrification significantly.

Imagine if you could ignore junctions, tunnels, level crossings, station footbridges.

The train just runs from battery over these sections. All you wire up with OHLE or install your third rail next to are the nice, simple straight sections that have plenty of room and are easy to maintain. The train runs through unwired sections off its batteries for a few hundred metres, no sweat at all. We already have trains that lower and raise their pantograph at speed, and third rail shoegear obviously has no problems dealing with gaps.

It also provides much more resiliency.

Problems with an electrified section? Turn it off, trains can still run through.
Wires down? drag them clear of the tracks and leave the maintenance until overnight, it doesn't affect services.

It is a shame NR is investing in OHLE now, at extraordinary expense, rather than investing in these sorts of technologies that might pay for themselves in a matter of years. I would like to see the billions of pounds being invested in traditional OHLE invested in these sorts of options instead, even if it means pausing new electrification for a few years, or even a decade.

 

[jopsuk]

it must be possible, for more lightly used and lower speed lines, to specify and design more "lightweight" kit. After all, if something like the West Highland Line was to be electrified, there's a good chance that service patterns and stock could be arranged such that only single units would run- so no need to worry about interactions on multiple pantographs, or with following trains. And perhaps some additional hydro power could be built as part of such a scheme- look to how Norway and Switzerland electrified for reference.

Freight terminals? a return of proper yard shunters (which may even be battery powered) picking up trains at the reception sidings is a solution.

 

[Indigo Soup]

And perhaps some additional hydro power could be built as part of such a scheme- look to how Norway and Switzerland electrified for reference.

That's unlikely - most of the feasibly hydroelectric schemes in the UK have already been done. There are a few pumped storage ones still available, but that's a slightly different animal.

Supposedly the North of Scotland Hydro-Electric Board sounded out the railways about electrification of the Highland lines - the Hydro Board was responsible for finding local uses for the power it generated as well as exporting it to the south - but there doesn't seem to have been much interest.

Freight terminals? a return of proper yard shunters (which may even be battery powered) picking up trains at the reception sidings is a solution.

Or indeed shunting tractors, or clever arrangements of reception sidings so that trains are propelled in and hauled out.

 

[reddragon]

I am not sure battery tech will be good enough to allow for stations to be the only charging sites and long distance services any time soon, you simply can't deliver that kind of energy quickly enough during a stop. A passenger train consumes around 3.5 kWh per carriage-mile, so a 12 coach London to Edinburgh service will need 16,800 kWh, or around 1200 kWh delivered at each of the 14 stops (ignoring the fact they are different distances apart). A Tesla's battery pack is 85kWh, so you'd need 15 of these at the very least for a full train journey. Not actually that impractical if perhaps, you had a couple under the floor of each coach, but to charge that in the few minutes you stop at a station is well beyond current technology. I also think doing that at a station might be a bad idea, given you want passengers as far away from electricity as is reasonably possible.

That said, I do think batteries could cut the costs of electrification significantly.

Imagine if you could ignore junctions, tunnels, level crossings, station footbridges.

The train just runs from battery over these sections. All you wire up with OHLE or install your third rail next to are the nice, simple straight sections that have plenty of room and are easy to maintain. The train runs through unwired sections off its batteries for a few hundred metres, no sweat at all. We already have trains that lower and raise their pantograph at speed, and third rail shoegear obviously has no problems dealing with gaps.

It also provides much more resiliency.

Problems with an electrified section? Turn it off, trains can still run through.
Wires down? drag them clear of the tracks and leave the maintenance until overnight, it doesn't affect services.

It is a shame NR is investing in OHLE now, at extraordinary expense, rather than investing in these sorts of technologies that might pay for themselves in a matter of years. I would like to see the billions of pounds being invested in traditional OHLE invested in these sorts of options instead, even if it means pausing new electrification for a few years, or even a decade.

Battery tech is there to enable this already, but scale-ability and manufacturing capacity & cost are not. That will take a while.

Think hybrid storage of electricity on the train and mixed charging infrastructure.

On the train there will be batteries to provide the base energy source but the station stop top ups will be to the latest ultra capacitors. Capacitors can charge instantly, in seconds. In China, electric busses use older style capacitors in this way already. So on the train there will be a mixture of batteries (slower to charge, hold their power for a long time) and capacitors (instant charge, no losses, but do not hold the charge for more than a few hours). This will enable any train to be electric without continuous electrification.

Power transfer will be via a 3rd / 4 rail system or via a short OLE section turned on only when activated. This type of system is now common on European tram systems. It also allows very rapid power transfers, quicker and safer than charging cables.

Some power sources will be grid fed, hence locations of OLE where that works best whilst at station stops, battery packs will slow charge & dump the power to a train when it calls.

As with all things, this will happen where it is easiest first and some types of service may take many years to be possible to convert.

 

[Cheshire Rover]

Battery tech is there to enable this already, but scale-ability and manufacturing capacity & cost are not. That will take a while.

Think hybrid storage of electricity on the train and mixed charging infrastructure.

On the train there will be batteries to provide the base energy source but the station stop top ups will be to the latest ultra capacitors. Capacitors can charge instantly, in seconds. In China, electric busses use older style capacitors in this way already. So on the train there will be a mixture of batteries (slower to charge, hold their power for a long time) and capacitors (instant charge, no losses, but do not hold the charge for more than a few hours). This will enable any train to be electric without continuous electrification.

Power transfer will be via a 3rd / 4 rail system or via a short OLE section turned on only when activated. This type of system is now common on European tram systems. It also allows very rapid power transfers, quicker and safer than charging cables.

Some power sources will be grid fed, hence locations of OLE where that works best whilst at station stops, battery packs will slow charge & dump the power to a train when it calls.

As with all things, this will happen where it is easiest first and some types of service may take many years to be possible to convert.

Pretty sure I have read somewhere that Merseyrail may be trialling this soon (2019/20?) between Ellesmere Port and Helsby.

 

[richieb1971]

Whatever is done, it needs to be done fast. With tech moving along at an accelerated pace any new traction/stock could be out of date in a very short space of time. Its better to build new stock based on a 30 year lifespan period than build something that can be replaced in 3 years time because we just didn't see what the future holds.

Are there any diesel builds going on at the moment or in the near future which could be obsolete in 3 years time when newer tech is mainstream running off the production lines?

 

[reddragon]

Whatever is done, it needs to be done fast. With tech moving along at an accelerated pace any new traction/stock could be out of date in a very short space of time. Its better to build new stock based on a 30 year lifespan period than build something that can be replaced in 3 years time because we just didn't see what the future holds.

Are there any diesel builds going on at the moment or in the near future which could be obsolete in 3 years time when newer tech is mainstream running off the production lines?

Any diesel electric train is easy to convert as the diesel power supply is replaceable by a battery. The class 230 is a good example. The 800 will be very easy to do.

Diesel mechanical / hydraulic systems such as sprinters are not an easy option, so all 1xx DMUs will have a limited future.

Electric trains are also easy to convert as seen with the class 319/769.

 

[apk55]

Some more points in favor of electrification

1/ Diesel engines can be quite efficient - however in railway applications there are long periods of idling and running on part load, efficiency is very considerably reduced. Often diesel engines or locomotives are sized so that the train can run at or near line speed on the most challenging part the route which means that for the rest of the route the engines are running inefficiently on part power. Also diesel trains may have bigger engines than needed just so they can accelerate quickly. The inflexible nature of torque converter transmission does not help. Diesel trans are also considerably heavier than an equivalent electric unit.
Electric trains are very efficient over the full power range particularly with high voltage AC where transmission losses are low.
2/ Battery are not that efficient when used at charge and discharge rates. Efficiency might be as high as 90% at low charge/discharge rates but could fall to 60% at high charge/discharge rates.

 

[Bletchleyite]

Any diesel electric train is easy to convert as the diesel power supply is replaceable by a battery. The class 230 is a good example. The 800 will be very easy to do.

Diesel mechanical / hydraulic systems such as sprinters are not an easy option, so all 1xx DMUs will have a limited future.

Electric trains are also easy to convert as seen with the class 319/769.

I wouldn't have thought it too hard to replace one thing that supplies a rotating shaft at a specified speed and torque range (diesel engine and mechanical transmission) with something else that does the same (batteries and an electric motor)?

Not a lot of point doing that to 15x, 16x or 17x when there are so many old EMUs going to be lying around which are much easier to convert, but 185s and 19x are probably going to be worth converting.

 

[reddragon]

Some more points in favor of electrification
2/ Battery are not that efficient when used at charge and discharge rates. Efficiency might be as high as 90% at low charge/discharge rates but could fall to 60% at high charge/discharge rates.

There is some truth in this, which is why trains will used capacitors in addition to rather than just batteries. The train will then perform just like an electric train.

 

[MarkyT]

For longer off-wire runs I present my concept of the 'Drone Locomotive', a short low bodied self powered 'slug' unit able to shunt around a station yard autonomously and attach to either end of any electric only unit that needs assistance. The low body ensures the driver can see over the unit from the normal driving cab if coupled at the front, like the old brake tenders used with early diesel locos. It could supply the majority if its power to the electric unit's traction motors through an inter-connector, or have sufficient traction motor capacity installed to haul or propel the electric unit as trailers at running speed in addition to itself.

 

[snowball]

That's true for older low-cost OLE, - thankfully, the industry in the UK has at last understood that you get what you pay for and the latest schemes, getting rid of daft headspans will much reduce the damage to wiring on adjacent tracks. With a busy mainline, any breakdown can cause a long line of queueing trains so there's not that much difference anyway.

Except that the vast increase in cost of the latest schemes is the reason why the prospects for electrification are so much lower today than 5 years ago.

 

[AM9]

Except that the vast increase in cost of the latest schemes is the reason why the prospects for electrification are so much lower today than 5 years ago.

But that's because the through-life cost isn't taken into consideration by politicians when sanctioning new work. Much of the GW scheme overrun has been put down to Railtrack not maintaing their records preventing the HOPS from being used as palnned.
How many times has the ECML been shut since the MKIIIb knitting was installed? Then multiply the number of services disrupted (or indeed lost) and calculate how much it would cost if the ECML was running under chargeable PPM. OLE is normally installed with a life expectancy of over 50 years, (think GEML, WCML aand Glasgow suburban schemes). The difference between a cheap job and doing it properly is a small price to pay to avoid not only the loss of a reliable service, but also the potential permanent loss of customer goodwill. I would imagine that the GWML around Hanwell will now be upgraded having had such a catastrophic failure this month.

 

[MarkyT]

Much of the GW scheme overrun has been put down to Railtrack not maintaing their records preventing the HOPS from being used as palnned.

I think it's a lot more complex than that. There was a fundemental planning error in assuming they could excavate large numbers of new stanchion footings with the old signalling still in operation. The correct sequence should have been Resignalling > Track changes, stanchion erection, bridge modifications > Wiring.

 

[B&I]

I think we are close enough in time to alternative technologies that would be cheaper than OHLE. Starting new long stretches of OHLE investment now seems about 50/50 on the silliness scale. Whilst OHLE does solve a few issues, it pushes bottlenecks elsewhere. For example, the 125mph speed limit on 90+% of our network due to signalling and bendy tracks etc. If you know capacity will rise and rise again, eventually you will start to realize that investment now just pushes us closer to the "Absolute maximum capacity" and where do you go from there.

This is why I think we should discourage people to travel.

I think we are a long way off this rather Soylent Greenish-scenario. We should be investing in rail capacity to get people off the roads

 

[B&I]

The rush for electrification of all transport, not just rail, doesn't deal with the resilience of the electricity network. In future, natural disasters or malicious events may see people and goods stranded with no prospect of sufficient and sufficiently expedient recovery in time to prevent complete societal breakdown.

Other than that, I'm fine with it.

I think you're mixing up total transport electrification with Brexit

 

[B&I]

There is something of a national security argument, in that electrification means that the continued functioning of the rail network requires an operational power supply network. Diesel or steam haulage will still work as long as you can get fuel (and water) to the locomotives. In practice, the Ministry of Defence wasn't concerned about comprehensive electrification proposals as even in the most extravagant schemes there would remain enough diesel locomotives to work essential traffic.

Fuel distribution also relies on elaborate infrastructure and computerised control systems, which are equally vulnerable to attack. During the UWC strike in Northern Ireland, fuel distribution was almost paralysed by a saboteur switching labels on the tanks at a single oil storage depot. My dad's Renault 12 was completely paralysed by a squaddie inadvertantly filling it with diesel as a result at a comandeered petrol station.

 

[LesF]

I always said that electrification didn't give us any extra miles of track or extra trains, so the money was better spent on other things. Then we had the rapid rise in oil price and I was pleased when the gov'ment announced extensive electrification including the Electric Spine (Southampton docks to Nuneaton). Now we know that gov'ment was seduced into electrification by the usual wildly optimistic figures, we have to think not whether it's justified in general but which lines are worthy of the expense and disruption. There's only one: MML, already electrified half way and crying out to be completed. Whether or not hydrogen power or another new technology eventually becomes viable for rail, it will make sense for MML to be wired in the medium term.
What we shouldn't do is to introduce another method of wiring that would fragment the network further. It's 25KV OLE or nothing. NetRail even wanted to convert the 3rd and 4th rail network to OLE because it's so much more efficient.
Re battery power, a Jaguar Land Rover engineer tells me that the battery pack costs £20,000 for each car and they have a short life. Will be megabucks for a train. And battery failure would leave trains stranded. The car industry is struggling to keep up with legislation and the rail industry lags behind. The only answer they have is that new technology may turn up. Not very reassuring!
The additional capacity we need lies in signalling - not the marginal improvements offered by ERTMS but a fully automated driverless system that allows trains to split and join on the move. We can split and join space vehicles at 18,000mph, aligning them in 3 dimensions, so we can do it in one dimension at 200mph for a train.

 

[Requeststop]

The problem with all transport is that to use energy you must create the energy, and the problem with our planet is that we humans are using more and more power inefficiently. What is needed is some genius to find the solution of producing more efficient uses of energy and something that in the end is cost effective. We are even now being told that eating meat is destroying our planet due to global warming. To produce electricity to must use energy. Be it from burning fuel in a power station, using wind, solar, or tidal power. The end product when using electricity is heat. The Law of Conservation of Energy. " Energy can neither be created nor destroyed; rather, it can only be transformed or transferred from one form to another." The problem is that the energy we use becomes heat energy, and we are slowly by the inefficient use of energy slowing heating up our planet". So lets get rid of all forms of transport, trains, motor vehicles, aircraft, shipping, and stay at home and fester - until a genius finds us that super-efficient and cheap power source.

 

[B&I]

I always said that electrification didn't give us any extra miles of track or extra trains, so the money was better spent on other things. Then we had the rapid rise in oil price and I was pleased when the gov'ment announced extensive electrification including the Electric Spine (Southampton docks to Nuneaton). Now we know that gov'ment was seduced into electrification by the usual wildly optimistic figures, we have to think not whether it's justified in general but which lines are worthy of the expense and disruption. There's only one: MML, already electrified half way and crying out to be completed. Whether or not hydrogen power or another new technology eventually becomes viable for rail, it will make sense for MML to be wired in the medium term.
What we shouldn't do is to introduce another method of wiring that would fragment the network further. It's 25KV OLE or nothing. NetRail even wanted to convert the 3rd and 4th rail network to OLE because it's so much more efficient.
Re battery power, a Jaguar Land Rover engineer tells me that the battery pack costs £20,000 for each car and they have a short life. Will be megabucks for a train. And battery failure would leave trains stranded. The car industry is struggling to keep up with legislation and the rail industry lags behind. The only answer they have is that new technology may turn up. Not very reassuring!

Sounds like a fairly comprehensive argument for electrification to me.

 

[reddragon]

Re battery power, a Jaguar Land Rover engineer tells me that the battery pack costs £20,000 for each car and they have a short life. Will be megabucks for a train. And battery failure would leave trains stranded. The car industry is struggling to keep up with legislation and the rail industry lags behind. The only answer they have is that new technology may turn up. Not very reassuring!
.

That is not true.

In cars a Petrol engine has a life of just over 100,000 miles; a diesel 150,000 miles before costly rebuilds. In that time its performance drops around 50%. A rail diesel engine is de-rated to extend its life but still requires regular expensive rebuilds.

An EV battery has a life known to be around 500,000 miles, with around a 10-15% capacity reduction but no performance reduction. Cells can be replaced to extend that life.

The whole drive-train cost of battery trains is currently higher than that of diesel, but the whole life cost is now similar. Diesel costs are going up rapidly, whilst the battery drive train is following Moore's Law, with cost halving every 18 months and the Kw/kg doubling every 18 months.

Rail born batteries are also lower tech than cars, hence more robust and longer life.

The Tesla Powerwall battery storage is lightweight car based tech, but the Powervault system costs twice as much per Kw stored & weights twice as much per Kw stored but has a degradation rate 25% of Tesla's batteries. Trains follow a different principle as weight is less important. Consequently, the Powervault system has half the cost in its life for energy stored & used compared to the Tesla system because although it stores less / weights more it is able to store & discharge much more over its life.

 

[swaldman]

While I don't wholly disagree with all of this post, let's add a bit of physics. Background: I'm not a railways expert, but I do understand energy.

Electrification as it is currently carried out has a bunch of problems...

The overall conversion efficiency from chemical energy of fuel to mechanical output from the wheels is not a lot different whether you use a remote generating plant and transmit the electricity, or a local plant and transmit the fuel. You get some benefit from remote generation using nuclear or renewable sources, but since most of our electricity still does come from fossil fuel (all this crowing about "no coal" days but they never mention that the replacement for all those closed coal power stations was gas ones...) and since railways use only a minor percentage of the fossil fuel used for transport, it's nothing like as much of a benefit as it's made out to be.

The last part is irrelevant, as it is energy use by railways that we're talking about here.
There were some good studies done back in about 2010-12ish showing that with the UK generation mix at the time (which then involved more coal, and less wind and solar, than it does now), electric cars were still about 40% more efficient than petrol or diesel ones, because large power stations are much more efficient than small internal combustion engines. Compared to cars that difference is probably decreased a little for a modern locomotive, as larger engines tend to be more efficient, but it won't be very different for DMUs that use truck engines, and the difference is probably greater for all those 50+ year-old diesels that we have running around. Additionally, you're not carrying around the weight of diesel engines and fuel....

The grid's carbon footprint has only decreased since then. Yes, there's a lot of gas, but we've had months recently where 20% of the UK's electricity has come from wind (not at a single moment, but averaged over the whole period). And it's only going to get better. It'll vary a bit according to the transmissions, but I'd be quite surprised if there's any diesel train that gets more tonne-km or passenger-km per megajoule of primary energy than an electric one of similar performance.

So there is an efficiency benefit for trains of similar performance.

It may even be a negative benefit, since not having to carry the generator about with you removes a major limitation on the power output of the train, and people are often tempted to specify grossly overpowered traction as a result. The additional power consumption wipes out any gain you might otherwise have got from part of the supply being nuclear or renewable. This is particularly the case when the temptation to go for excessive speed also comes into it - energy consumption for a given journey varies as the square of the speed (and power consumption as the cube), but the reduction in journey time is often nugatory especially when you consider the total time end-to-end as opposed to just that part of it spent on a moving train.

Speed is certainly expensive, and I agree that a faster train uses more energy to make the same journey. Starting and stopping a lot is also obviously wasteful, so accelerating hard only to then have to slow is something to be avoided, and fast running interspersed with time stopped should also be avoided (I imagine these are avoided where forseeable?) - although the impact of this is less with electrics if they can use regenerative braking.

But speed is a different benefit of electrification. Once you electrify you can potentially choose whether you want to go faster, or use less energy. I can't think of any reason that the amount of power that the train available has should make much difference to the amount of energy used, given the same average speed and an avoidance of unnecessary fast/slow or start/stop operation.

It's kind of daft for minor routes that see little traffic, especially those that are in remote and inhospitable places (like the Highlands) which add harsh weather and difficult access to the extra maintenance the wiring needs anyway.

I agree with this. At some point, for low-traffic routes, electrification must just be silly. If you're making the big investment in infrastructure, you need to run a certain number of journeys within its lifetime to make it worthwhile!

It is ugly as arseholes.

Fair

 

[reddragon]

There were some good studies done back in about 2010-12ish showing that with the UK generation mix at the time (which then involved more coal, and less wind and solar, than it does now), electric cars were still about 40% more efficient than petrol or diesel ones, because large power stations are much more efficient than small internal combustion engines. Compared to cars that difference is probably decreased a little for a modern locomotive, as larger engines tend to be more efficient, but it won't be very different for DMUs that use truck engines, and the difference is probably greater for all those 50+ year-old diesels that we have running around. Additionally, you're not carrying around the weight of diesel engines and fuel....

The grid's carbon footprint has only decreased since then. Yes, there's a lot of gas, but we've had months recently where 20% of the UK's electricity has come from wind (not at a single moment, but averaged over the whole period). It'll vary a bit according to the transmissions, but I'd be quite surprised if there's any diesel train that gets more tonne-km or passenger-km per megajoule of primary energy than an electric one of similar performance.

The most efficient diesel engines can now (once warmed up and in perfect conditions) can convert ~40% of the fuel energy into power.
Once you include losses in the power train, production and transportation energy the well to power output to wheel is actually about 15% efficient.
Unfortunately, braking energy is wasted and much time is spend idling so the full well to rail / road efficiency is only about 5%

With electric cars / trains using regen power via OLE or batteries efficiency is around 90%.
Losses on the Power Station to vehicle are around 25% (source to power station is tiny now most is gas / renewable)
So the total efficiency from energy source to rail / road efficiency is about 70%

I understand that with today's grid mix an electric vehicle / train emits around 20% of the gases of a diesel powered vehicle

 

[najaB]

Diesel haulage is still needed for trains that run over routes which are only partly electrified. Particularly awkward for freight, with the kind of twiddly bits at the ends, perhaps even on private land, that would need to be wired. Or where the wires would get in the way of loading.

Class 88.