Battery power and bi-mode vs electrification

[InTheEastMids]

delivering that much charge in say 10 mins equates to up to 2.4MW.

The rate limiting step is therefore equally likely to be the power conversion system on the train - i.e. it's not likely to be able to charge at a higher power than whatever the traction systems can accomodate, which was suggested above at 1.2 MW. Also, in the real recharge rates in EVs can be a lot less than their theoretical maximum, particularly if the state of charge is below 20% or above 80%.

Assuming the same is also true of a battery train with 1.2 MW of traction power, then the peak recharge rate might get within touching distance of 1.2 MW at times, but in reality the sustained recharge rate in the real world might be more like perhaps 800 kW - 1 MW.

This might mean that converted BMUs are a bit sub-optimal as it could lead to longer dwell/turnaround times at charging locations if full charges are required.

 

[cjmillsnun]

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

Hopefully by the time the first set of batteries degrades we should be looking at the lines being electrified (one can dream). It would be a fairly simple conversion to remove the batteries and convert to non battery EMU

 

[mike57]

That's why the proposal for those lines is hydrogen, with fuel cells to turn it into electricity.

I think the main problem with Hydrogen technology is that it is still relatively unproven in large scale applications, and I suspect there could be some problems with it, thats not to say it shouldn't be developed, but it doesn't look mature enough for large scale deployment.

miniscule. rail today is only responsible for 1.6% of all UK emissions

Which brings me back to an earlier point, get on with electrification of the main routes, and leave the remote rural routes as they are using proven diesel technology, and spend the time and effort on other areas of the economy that contribute far higher emissions. If rail is 1.6% of all emissions then I would guess that the rural routes that will probably never be electrified across the UK contribute less than 10% of that 1.6% i.e. 0.16%, and eliminating that is pointless.

 

[Bald Rick]

I wonder will this mean Merseyrail consider fitting all the 777s with the batteries to allow for the simpler regen? Would also mean a homogeneous fleet, so no trains being cancelled short at Kirkby when a non-battery unit inevitably ends up on a Kirkby diagram, just like the way TfW seem to find it impossible to keep the ETCS 158s on diagram?

I think the Merseyrsil system can already accept regen, and there is a regular enough frequency on most lines for it to be useful. Where there isn’t the regen can often simply make up for the system losses in the low voltage side of the DC System.

 

[Wtloild]

The worry with bi-modes is that whilst they're a good interim solution, they end up as an excuse for never electrifying or for continually postponing planned electrifications ("Graylinged").
There are major routes and/or connecting in-fill in England & Wales that aren't even yet being considered, which in Scotland would already be electric, or at least at the planning stage - e.g. lines into Hull, lots of lines round Birmingham, Leeds, Cross-Country connections between the various spines.

 

[CdBrux]

it’s only zero emission if produced from renewable electricity

Absolutely!
If (potentially big if for a few years yet) that production could be in periods when renewables may otherwise be switched off as supply > demand (i.e. wind at night) then the energy to produce the hydrogen will be effectively close to free - same for charging a battery bank. Indeed the hydrogen production is then in effect just a different way to store and re-use energy and I sometimes have an impression those who are quick to rubbish hydrogen overlook this.

 

[paul1609]

The rate limiting step is therefore equally likely to be the power conversion system on the train - i.e. it's not likely to be able to charge at a higher power than whatever the traction systems can accomodate, which was suggested above at 1.2 MW. Also, in the real recharge rates in EVs can be a lot less than their theoretical maximum, particularly if the state of charge is below 20% or above 80%.

Assuming the same is also true of a battery train with 1.2 MW of traction power, then the peak recharge rate might get within touching distance of 1.2 MW at times, but in reality the sustained recharge rate in the real world might be more like perhaps 800 kW - 1 MW.

This might mean that converted BMUs are a bit sub-optimal as it could lead to longer dwell/turnaround times at charging locations if full charges are required.

Converted bemus would also be suboptimal for charging on the move as the total traction/ recharging power is limited by the original spec of the ac transformer and cabling or collection shoes and train bus in the case of dc. On the modelling GTR did for replacing the 171s. South Croydon to Hurst Green existing electrification couldn't support the existing Uckfield trains being straight electric let alone bemus.
On Marshlink replacement the low charge rate available on Hampden Park to Brightons electrification meant that to cover the Ore to Ashford Gap the trains had to do a Brighton to Ashford cycle followed by a Brighton to Seaford cycle, this meant that the number of BEMU diagrams required to cover the 5 171 diagrams was huge.

 

[Bletchleyite]

Converted bemus would also be suboptimal for charging on the move as the total traction/ recharging power is limited by the original spec of the ac transformer and cabling or collection shoes and train bus in the case of dc. On the modelling GTR did for replacing the 171s. South Croydon to Hurst Green existing electrification couldn't support the existing Uckfield trains being straight electric let alone bemus.
On Marshlink replacement the low charge rate available on Hampden Park to Brightons electrification meant that to cover the Ore to Ashford Gap the trains had to do a Brighton to Ashford cycle followed by a Brighton to Seaford cycle, this meant that the number of BEMU diagrams required to cover the 5 171 diagrams was huge.

Get it upgraded, then. The excuses really need to stop; diesel has to be removed.

 

[Skie]

I think the Merseyrsil system can already accept regen, and there is a regular enough frequency on most lines for it to be useful. Where there isn’t the regen can often simply make up for the system losses in the low voltage side of the DC System.

Only in the core is there the density of service to make it really useful. But they’ve also spent a lot recently to enable regen on the network and to improve the power supply in some of the more remote areas. Battery units being used en-masse could have changed both of those requirements and saved a lot of money. Not useful on Merseyside now, but it should feed into the planning for other areas.

 

[paul1609]

Get it upgraded, then. The excuses really need to stop; diesel has to be removed.

or possibly just kick ORR and Network Rail in to finally electrifying both lines rather than complicated unproven technology that in the long run will cost more anyway. Neither scheme nor the north down lines is particularly complicated or extensive.

 

[Trainbike46]

Those small diesel islands do have a lot of benefits for relatively little extra installed electrification; England, Wales and NI really need to get a move on

 

[Doomotron]

Those small diesel islands do have a lot of benefits for relatively little extra installed electrification;

Marshlink does; it is a strategic route for high speed services from London to Hastings, which are currently impossible to do. Additionally it means trains don't need to terminate at Ore, potentially allowing for most or all trains that terminate at Ore or Hastings from Brighton/London to be extended to Rye and Ashford.

Electrifying Uckfield also means less 230m diesel trains in the centre of London. The diesel islands in general are massive annoyances logistically, as particularly on Southern they require a microfleet of slow and badly maintained diesel units spread between two routes on opposite sides of the Southern network. The only way it could be more inconvenient is if Southern ran the Bletchley to Bedford line.

 

[InTheEastMids]

South Croydon to Hurst Green existing electrification couldn't support the existing Uckfield trains being straight electric let alone bemus.

This is a very good point. Constraints on BEMU charging rates could come from the train, the infrastructure, or a combination of both.

Absolutely!
If (potentially big if for a few years yet) that production could be in periods when renewables may otherwise be switched off as supply > demand (i.e. wind at night) then the energy to produce the hydrogen will be effectively close to free - same for charging a battery bank. Indeed the hydrogen production is then in effect just a different way to store and re-use energy and I sometimes have an impression those who are quick to rubbish hydrogen overlook this.

Yes, a high-renewables electricity system is also almost certainly a high-hydrogen energy system. However, you'd need to have a wind/solar farm that was constrained so often that is made the business case for hydrogen production stand up (vs alternatives of accepting the constraints or other technical solutions like batteries). I'm not sure this has happened yet.

Although just because green hydrogen can be made, doesn't automatically means that (rural) trains are a good use of it, there's other big industrial applications which are less easy to substitute with electricity.

Get it upgraded, then. The excuses really need to stop; diesel has to be removed.

I sympathise with the frustration. Distribution network capacity may be a big part of the issue, both the cost and the technical deliverability.

A small glimmer of hope is whether the significant code review for new power network connections that comes into effect in April 2023 brings down the cost and lead times of rail electrification schemes.

 

[100andthirty]

In terms of any electrification there are really only three components....1) enough electricity, 2) getting the electricity to the railway and 3) distributing the electricity along the railway (OLE or 3rd rail). Each of these has civil engineering and electrical engineering components.

Using batteries instead of OLE/3rd rail only avoids the cost of point 3). Instead there's the cost of the batteries and the extra power consumed in carrying them around.

 

[Bald Rick]

In terms of any electrification there are really only three components....1) enough electricity, 2) getting the electricity to the railway and 3) distributing the electricity along the railway (OLE or 3rd rail). Each of these has civil engineering and electrical engineering components.

Using batteries instead of OLE/3rd rail only avoids the cost of point 3). Instead there's the cost of the batteries and the extra power consumed in carrying them around.

whilst this is true, your (3) is by far the most costly part.

 

[100andthirty]

This may be true in terms of cost, but 1) and 2) can take significantly more time than 3) if not carefully planned

 

[Bald Rick]

This may be true in terms of cost, but 1) and 2) can take significantly more time than 3) if not carefully planned

of course. But thats irrelevant to the battery vs electric action equation, as it is the same for both.

 

[Nicholas Lewis]

or possibly just kick ORR and Network Rail in to finally electrifying both lines rather than complicated unproven technology that in the long run will cost more anyway. Neither scheme nor the north down lines is particularly complicated or extensive.

BEMUs aren't unproven technology they have been in use across a number of Japanese rural lines since 2015 and there are several European operators who have them on order. Not forgetting that DB had an extensive battery operated railbus fleet from the 1950's that lasted well into the 1980's. For sure whats complicated is they are more constrained than straight diesel or electric units in how they deployed each day but once the constraints are understood diagrams can easily be formulated.

That said it is plain daft that these routes should be an outlier in all DC electrification operated area. RSSB were supposed to have completed there report into how to safely extend the DC system but its still in abeyance. This was to inform a "modern day" safety case to demonstrate to ORR that it complies with todays H&S regulations.

 

[Bald Rick]

BEMUs aren't unproven technology they have been in use across a number of Japanese rural lines since 2015 and there are several European operators who have them on order. Not forgetting that DB had an extensive battery operated railbus fleet from the 1950's that lasted well into the 1980's. For sure whats complicated is they are more constrained than straight diesel or electric units in how they deployed each day but once the constraints are understood diagrams can easily be formulated.

They have been in regular passenger service in this country for nearly three years!

 

[Richard Scott]

Get it upgraded, then. The excuses really need to stop; diesel has to be removed.

For the most I'd agree but not at any cost. Decarbonisation is as much a political issue as a real environmental one. Does converting a diesel line to electric or battery operation actually achieve anything if line is sparsely used? We need to remember everything has a carbon footprint (this is an important point that is overlooked in many cases) so need to establish what is the footprint of electrification or battery trains compared to existing diesel trains? It seems that diesel is seen as a demon and electricity is the saviour and that it must prevail. This may not actually be the best option for some lines. We need to ensure there is a real benefit not just a political one.

 

[Bletchleyite]

For the most I'd agree but not at any cost. Decarbonisation is as much a political issue as a real environmental one. Does converting a diesel line to electric or battery operation actually achieve anything if line is sparsely used? We need to remember everything has a carbon footprint (this is an important point that is overlooked in many cases) so need to establish what is the footprint of electrification or battery trains compared to existing diesel trains? It seems that diesel is seen as a demon and electricity is the saviour and that it must prevail. This may not actually be the best option for some lines. We need to ensure there is a real benefit not just a political one.

The political argument is too powerful to disregard. It will be electrify/battery/hydrogen or close. Close might be a valid answer, of course, but diesel will become so deprecated the decision will be forced one way or the other.

It might be possible to buy time by converting to 100% rapeseed biodiesel and adding exhaust scrubbers to reduce particulate emissions to basically zero, but that'll only buy time.

 

[Richard Scott]

The political argument is too powerful to disregard. It will be electrify/battery/hydrogen or close. Close might be a valid answer, of course, but diesel will become so deprecated the decision will be forced one way or the other.

It might be possible to buy time by converting to 100% rapeseed biodiesel and adding exhaust scrubbers to reduce particulate emissions to basically zero, but that'll only buy time.

But that's the problem, yet again it's politics over real science/engineering. Electrification, in the real world, is the best option for majority of lines but there are a few where diesel (whether biodiesel or otherwise) actually makes the most sense.

 

[Bletchleyite]

But that's the problem, yet again it's politics over real science/engineering. Electrification, in the real world, is the best option for majority of lines but there are a few where diesel (whether biodiesel or otherwise) actually makes the most sense.

The political argument against the use of diesel cannot be ignored, however much you may want it to be.

If it is the result will be line closures.

 

[Richard Scott]

The political argument against the use of diesel cannot be ignored, however much you may want it to be.

If it is the result will be line closures.

I know that, my point is it's politics over science as usual.

 

[Doomotron]

If it is the result will be line closures.

However, this will likely be political suicide to a greater extent than not achieving net zero!

 

[Bletchleyite]

However, this will likely be political suicide to a greater extent than not achieving net zero!

I don't agree. An electric coach replacement for branch lines at a higher frequency would be fairly easy to sell.

 

[Bald Rick]

I don't agree. An electric coach replacement for branch lines at a higher frequency would be fairly easy to sell.

whilst I agree with the idea, it’s not been an easy sell anywhere yet.

 

[Bletchleyite]

whilst I agree with the idea, it’s not been an easy sell anywhere yet.

When they eventually get the hourly Conwy Valley service going with the electric buses it will be interesting to see who uses what.

 

[Bald Rick]

When they eventually get the hourly Conwy Valley service going with the electric buses it will be interesting to see who uses what.

it will be even more interesting if TfW have the stomach to close the line, and if they do, how they go about doing it.

 

[supervc-10]

I do wonder if biodiesel is the way forward with these lesser used lines. Whilst biodiesel is very questionable in terms of actual green-ness, it's something that is often touted by politicians as a zero-emission fuel (which, as I've said, is very questionable at best) but as a result it's something that's politically on the table.