Has electrification had its day?

[paul1609]

U.K. Grid average is much lower than that. This year it has been 167g/kWh. Last year it was 188g/kWh. Right now it’s 91g.

As I posted elsewhere (possibly upthread), you can argue three different scenarios for U.K. rail electricity carbon consumption:

1) zero (or nearly so) as Network Rail contracts with EDF for Nuclear baseload on a ‘zero’ carbon tariff

2) Grid average (167g/kWh), as electrons are agnostic

3) the carbon rate of the marginal generation necessary to power U.K. rail - ie if rail wasn’t drawing power, which power generators would be switched out, and their carbon emissions avoided. Often this is CCGT, but not always. On windy nights, or sunny breezy days, after CCGT has been reduced to a minimum, biomass is turned down, as are the imports from Europe, and often wind farms are switched out. We were in that position 4 hours ago - electricity prices were negative. In these situations, the marginal power for U.K. rail is also zero carbon. That is likely to happen more frequently as more wind comes on stream - approx 2GW a year for the next 6 years.

So your argument for the carbon free future is for the rail industry to run a boxing day passenger service every day?

 

[Bald Rick]

So your argument for the carbon free future is for the rail industry to run a boxing day passenger service every day?

No. And that wasn’t what I was suggesting, as you well know!

 

[Domh245]

U.K. Grid average is much lower than that. This year it has been 167g/kWh. Last year it was 188g/kWh. Right now it’s 91g.

That's interesting, presumably that's just CO2, as opposed to CO2e? The BEIS conversion factors has pure CO2 emissions down as 231g/kWh so it's interesting to see that it's actually even much lower than that

Then there's the emissions just getting the fuel to the train in the first place, admittedly there with some electricity generation but would imagine this is lower.

Indeed - the "well to tank" emissions which are an estimate of all the associated emissions from extraction, refining and distribution to the point of use. For diesel in the UK it's a little over 0.6kg CO2e/litre of diesel (.06kg co2e/kWh net), whereas electricity has a well to tank of 0.03kg co2e/kwh and transmission losses of around .02kg co2e/kwh, so electricity's 'indirect' emissions are about 10% less

 

[paul1609]

No. And that wasn’t what I was suggesting, as you well know!

I like this site. https://carbonintensity.org.uk
Possible rail electrification should be based on Regional Carbon Intensity.
Marshlink, Uckfield and Transpennine should be the priority.
HS2 and MML should be scrapped.
South Wales shouldn't be touched with a bargepole.

 

[Philip Phlopp]

I like this site. https://carbonintensity.org.uk
Possible rail electrification should be based on Regional Carbon Intensity.
Marshlink, Uckfield and Transpennine should be the priority.
HS2 and MML should be scrapped.
South Wales shouldn't be touched with a bargepole.

We're not doing electrification solely to reduce the carbon emissions of rail transportation - it is one positive aspect of rail electrification, but also resulting from rail electrification is reductions of energy intensity overall (the amount of energy needed to move one passenger one km) and reductions of other emissions, particuarly nitrogen oxides (NOx) and particulate emissions (PM), whilst electrification also allows lighter, more reliable rolling stock which reduces track wear and improves the overall reliability of the rail network.

When looking at where we need to electrify as a priority, it's a complex series of calculations looking at passenger numbers, service patterns, energy savings, performance enhancements, reliability improvements and existing infrastructure status.

The service intensity is why South Wales makes great sense, particularly the Valley Lines. The performance gains, energy efficiency improvements and emission reductions are why the MML should be completed, even with the impending arrival of high performance Class 810 bi-mode units.

 

[Energy]

I like this site. https://carbonintensity.org.uk
Possible rail electrification should be based on Regional Carbon Intensity.
Marshlink, Uckfield and Transpennine should be the priority.
HS2 and MML should be scrapped.
South Wales shouldn't be touched with a bargepole.

You're reply is not only very questionable but also doesn't address what Bald Rick said which you are replying to.

First of the site you link shows this as the map:


You say South Wales shouldn't be touched with a barge pole yet it is in yellow? Cancelling MML electrification is stupid. It is a very busy diesel line and would easily reduce diesel running in the UK.

I agree that Marshlink and Uckfield should be electrified but mainly because they are a diesel island. Transpennine is desperate for electrification.

Scrapping HS2 is stupid. HS2 is to release capacity on the mainlines, not much to do with electrification.

 

[Greybeard33]

This actually seems a more sensible suggestion. Attach a battery locomotive at end of electric section to run over non-electrified section and then can be removed upon return to the electrified section. Unit then not carrying tons of batteries around when on juice. Obviously locomotives would have reasonable down time whilst they charge so may be more expensive initially due to investment in said locomotives.

The devil is in the detail with that idea.

Would the battery loco supply traction power to the EMU, or would it just supply auxiliary power (for aircon etc.) and haul/propel the carriages as dead weight? With the first option the loco could have smaller traction motors, since it would only have to propel itself, and wheel/rail adhesion would be less of an issue. But the coupling would have to transmit multi-MW power levels, yet be capable of reliable and rapid mating/demating.

The weight of the loco could be an issue on some branch lines, with all the battery weight concentrated in the one vehicle.

The extra length of the train could be an issue at some stations, e.g. if a level crossing precluded the loco stopping off the end of the platform.

Loco charging sidings would have to be constructed at the start of each non-electrified section. In some cases the power supply would need the capacity to charge two locos at once, which could be challenging.

The EMUs would have to be built, or modified, to be compatible with the battery loco's multiple working system. Unless this was satisfactorily standardised between different loco and EMU suppliers, it could lead to a lack of flexibility in rolling stock procurement and in moving units around the network.

 

[Richard Scott]

The devil is in the detail with that idea.

Would the battery loco supply traction power to the EMU, or would it just supply auxiliary power (for aircon etc.) and haul/propel the carriages as dead weight? With the first option the loco could have smaller traction motors, since it would only have to propel itself, and wheel/rail adhesion would be less of an issue. But the coupling would have to transmit multi-MW power levels, yet be capable of reliable and rapid mating/demating.

The weight of the loco could be an issue on some branch lines, with all the battery weight concentrated in the one vehicle.

The extra length of the train could be an issue at some stations, e.g. if a level crossing precluded the loco stopping off the end of the platform.

Loco charging sidings would have to be constructed at the start of each non-electrified section. In some cases the power supply would need the capacity to charge two locos at once, which could be challenging.

The EMUs would have to be built, or modified, to be compatible with the battery loco's multiple working system. Unless this was satisfactorily standardised between different loco and EMU suppliers, it could lead to a lack of flexibility in rolling stock procurement and in moving units around the network.

Agree it's not a perfect solution and brings in its own issues as you point out. The benefit of it was eliminating the need to charge at a particular spot at a particular time and also took away need to carry batteries around when not needed.
The biggest problem would be overcoming this country's aversion to anything loco hauled even if it were to be the most sensible solution.

 

[Bald Rick]

That's interesting, presumably that's just CO2, as opposed to CO2e? The BEIS conversion factors has pure CO2 emissions down as 231g/kWh so it's interesting to see that it's actually even much lower than that

Look at the dates on the BEIS data tables. The 231g/kWh is the 2018 number reported, which may well have been for the 2017 calendar year. The data source I use: https://electricinsights.co.uk/#/dashboard?_k=eyhf3v has the 2017 calendar year at 235g/kWh, which is pretty close.

The decarbonisation of the grid has been remarkably quick - it’s more than halved in 5 years, and likely to halve again in another 5-6 years.

 

[Domh245]

Look at the dates on the BEIS data tables. The 231g/kWh is the 2018 number reported, which may well have been for the 2017 calendar year. The data source I use: https://electricinsights.co.uk/#/dashboard?_k=eyhf3v has the 2017 calendar year at 235g/kWh, which is pretty close.

The decarbonisation of the grid has been remarkably quick - it’s more than halved in 5 years, and likely to halve again in another 5-6 years.

I'd managed to completely gloss over that the data used for that is several years out of date! It's disappointing to see that this hasn't been updated despite the data being out there, but I suppose that the upside is the UK is significantly overreporting it's carbon emissions (including the ORR in their annual emissions report) and individual organisations potentially over-offsetting or aggressively reducing consumption to drag their footprint down.

The rapid decarbonisation is definitely heartening to see

 

[The Ham]

You're reply is not only very questionable but also doesn't address what Bald Rick said which you are replying to.

First of the site you link shows this as the map:

View attachment 87677
You say South Wales shouldn't be touched with a barge pole yet it is in yellow? Cancelling MML electrification is stupid. It is a very busy diesel line and would easily reduce diesel running in the UK.

I agree that Marshlink and Uckfield should be electrified but mainly because they are a diesel island. Transpennine is desperate for electrification.

Scrapping HS2 is stupid. HS2 is to release capacity on the mainlines, not much to do with electrification.

The other thing to note is that even when South Wales is orange it's still generating 29% of its electricity from wind with the rest being gas.

Over the timeframe of most electrification projects gas use is likely to fall significantly (bear in mind that in 2014 nationally about 30% of all electricity was from coal).

 

[Jozhua]

This actually seems a more sensible suggestion. Attach a battery locomotive at end of electric section to run over non-electrified section and then can be removed upon return to the electrified section. Unit then not carrying tons of batteries around when on juice. Obviously locomotives would have reasonable down time whilst they charge so may be more expensive initially due to investment in said locomotives.

Hmm, it's definitely a lot more practical than changing several tonnes of batteries, but it would probably have a number of hurdles.

By my calculation the non carbon electricity in the UK grid mix has now been allocated at least 200% of its actual capacity. You therefore have to calculate that any increased electricity consumption by the rail industry (new electrification) is generated by closed circuit gas turbine power stations. Once the transmission losses etc are taken in to account I doubt there is much reduction in CO2 by new electrification. Alternatively you could factor the cost of new nuclear power stations to power rail in to the business case.

How come they were doing electrification before climate change was even known about?

Maybe it's because it's more efficient, reduces long term costs and improves service.

So your argument for the carbon free future is for the rail industry to run a boxing day passenger service every day?

What's your argument for doing so without electrifying?

You're reply is not only very questionable but also doesn't address what Bald Rick said which you are replying to.

First of the site you link shows this as the map:

View attachment 87677
You say South Wales shouldn't be touched with a barge pole yet it is in yellow? Cancelling MML electrification is stupid. It is a very busy diesel line and would easily reduce diesel running in the UK.

I agree that Marshlink and Uckfield should be electrified but mainly because they are a diesel island. Transpennine is desperate for electrification.

Scrapping HS2 is stupid. HS2 is to release capacity on the mainlines, not much to do with electrification.

MML is one of the few mainlines out of London to be non-electrified now? Well that and GWR.

Can't believe people suggest cancelling HS2 and "improving existing routes", while also defending the cancellation of electrification on said existing routes.

Squeesing any higher speeds, or indeed much more capacity, out of the MML will require electrification. The electrification done so far seems like it will be quite lightly used, if I'm right in assuming the majority of services will still be going through to Leicester, Notts, Derby and Sheffield?

The devil is in the detail with that idea.

Would the battery loco supply traction power to the EMU, or would it just supply auxiliary power (for aircon etc.) and haul/propel the carriages as dead weight? With the first option the loco could have smaller traction motors, since it would only have to propel itself, and wheel/rail adhesion would be less of an issue. But the coupling would have to transmit multi-MW power levels, yet be capable of reliable and rapid mating/demating.

The weight of the loco could be an issue on some branch lines, with all the battery weight concentrated in the one vehicle.

The extra length of the train could be an issue at some stations, e.g. if a level crossing precluded the loco stopping off the end of the platform.

Loco charging sidings would have to be constructed at the start of each non-electrified section. In some cases the power supply would need the capacity to charge two locos at once, which could be challenging.

The EMUs would have to be built, or modified, to be compatible with the battery loco's multiple working system. Unless this was satisfactorily standardised between different loco and EMU suppliers, it could lead to a lack of flexibility in rolling stock procurement and in moving units around the network.

I feel like a battery trailer may be more practical than a loco? Although it would need some motive power to move itself about.

Obviously adding a number of labour/time costs there too as well. So not massively practical for small branch lines.

Agree it's not a perfect solution and brings in its own issues as you point out. The benefit of it was eliminating the need to charge at a particular spot at a particular time and also took away need to carry batteries around when not needed.
The biggest problem would be overcoming this country's aversion to anything loco hauled even if it were to be the most sensible solution.

Loco hauled has it's pitfalls vs MU's. MU's can accelerate faster with distributed traction and have some level of redundancy.

Loco hauled seems like it would be a bit cheaper for longer trains. But then again, the only trains at that length (8 cars +) are either 3rd rail commuter services or express services out of London.

I think because our network tries to squeeze so much out, there isn't really much space for what loco-hauled provides.

Plus, we have fairly short turnaround times compared to some of our larger European neighbours, so DVTs are a must.

 

[Domh245]

Squeesing any higher speeds, or indeed much more capacity, out of the MML will require electrification.

It won't, at least not practically. The 222s (and 'similarly performing on diesel' 810s) have such high acceleration in the first place that going to full electric really doesn't have much benefit, you'd only gain a handful of minutes by running as EMUs. It certainly isn't enough to squeeze more capacity out, particularly as it is the southern end of the line with the Thameslink services that is the main capacity constraint. The main reason for electrifying the rest of the MML are the environmental benefits and associated operational benefits from removing diesel (weight, reliability)

 

[Irascible]

Didn't we have the same argument about discrete modal power vs onboard bi-mode when the IET was being specced? staff needed to make shunting moves, availability of the addon power, etc. There is another point I don't think was raised yet, and that's that batteries would actually be quite useful even under wires - in much the same way a true hybrid works, if you draw from the battery while accelerating & charge it while you're cruising & coasting, you reduce your draw from the OHLE a fair bit. Probably not something to spec every EMU for because you're still expending energy hauling batteries around, but in places with patchy wires ( 3rd rail too ) and/or perhaps a less robust power supply, it might help reduce service constraints.

 

[Richard Scott]

Didn't we have the same argument about discrete modal power vs onboard bi-mode when the IET was being specced? staff needed to make shunting moves, availability of the addon power, etc. There is another point I don't think was raised yet, and that's that batteries would actually be quite useful even under wires - in much the same way a true hybrid works, if you draw from the battery while accelerating & charge it while you're cruising & coasting, you reduce your draw from the OHLE a fair bit. Probably not something to spec every EMU for because you're still expending energy hauling batteries around, but in places with patchy wires ( 3rd rail too ) and/or perhaps a less robust power supply, it might help reduce service constraints.

Almost the principle behind the 71 and its booster set? I know that was to prevent the loco becoming stuck on a gap in 3rd rail but certainly a similar idea?

 

[Irascible]

Almost the principle behind the 71 and its booster set? I know that was to prevent the loco becoming stuck on a gap in 3rd rail but certainly a similar idea?

More like a hybrid car - you can drive it short distances on the battery obviously but that's not the main point - you can certainly accelerate faster than it's IC engine would suggest. In this case the power the IC engine provides is coming from an external source. Ideally you'd want the batteries at the power source rather than on the train, but if the distribution infrastructure is poor ( or deliberately lower specced ) then onboard storage of some sort could certainly help flatten demand.

Equally you could try making the train use less energy, of course... but noi matter how light it is you'll always get a peak draw under acceleration.