Although we waited longer than expected for its arrival, when it came the Transport Decarbonisation Plan didn’t disappoint.
As with many government documents, it left more questions than answers.
However, the ‘Greenprint’, as it has been dubbed, did begin to map out where we are heading - particularly when it comes to decarbonisation of the railways.
The paper highlights five key priorities required to deliver a net-zero railway by 2050. First, an ambition to remove all diesel-only trains, both passenger and freight, by 2040. Then a pledge to support the development of battery and hydrogen trains.
There was also a need to build extra capacity on the network, and to modernise fares to encourage more people to use the railways.
But the most far-reaching priority - and the one that has got many people talking - is the pledge to deliver what the plan states is “an ambitious, sustainable and cost-effective programme of electrification”.
The programme will be guided by the work already carried out by Network Rail in its Traction Decarbonisation Network Strategy, published last summer.
The strategy made it clear that although rail contributes less than 1% of the total UK annual greenhouse gas emissions, it is in the “unique position” of being the only transport mode capable of moving both people and heavy goods using a zero-carbon solution.
The railways aren’t the only transport sector requiring radical changes to meet the net-zero target.
Virtually everything that moves will need to shift to a more environmentally friendly mode of operation.
Buses are going electric already, and more towns and cities will receive replacement fleets.
Coventry looks set to become the first, with its entire 300-strong fleet going electric as part of government efforts to improve air quality.
Some buses are also being powered by hydrogen. Aberdeen has been the trailblazer, but other cities are now catching up with Birmingham about to launch a fleet of 20 hydrogen buses, and there are already rumours that more could be coming soon.
There’s a conundrum when it comes to commercial traffic. Vans and short-haul lorries are expected to go down the electric vehicle (EV) route, but that’s not the answer for long-distance HGVs. Meanwhile, bulky and heavy batteries could reduce space for cargo, making journeys uneconomic.
Most seem to think the future for long haul is hydrogen. However, there are still issues with the manufacture of the gas - it is still very energy-intensive, and most production currently isn’t particularly green either. Alternative production methods are being developed, but so far few have been proven at scale.
But even with those issues resolved, it’s clear that demand for electricity is set to rise. We need to be prepared.
For the railways, electrification may seem the logical way forward.
After all, it’s been the mainstay of a sustainable railway for years.
However, providing that reliable green transport isn’t that simple. There are a mix of solutions, and clearly electrification is just one part of an evolving story.
In its initial report back in 2019, the Rail Industry Decarbonisation Taskforce suggested that the greatest challenge on traction was the type of journeys being made.
On some, there are real possibilities for the introduction of new technology, such as hydrogen fuel cells and the use of battery propulsion.
Other journeys, such as freight and high-speed inter-city services, have journey characteristics that demand very high energy and power delivery requirements, high acceleration, and long periods between refuelling.
And here, only more electrification can provide what’s needed.
As has been learned from the recent upgrade of the Great Western Main Line, electrification isn’t going to be quick or cheap… and there remains the issue of how you get vast amounts of additional power to the parts of the railway where it’s needed.
There have already been many stories about limited capacity for electric vehicle charging, because of issues with local distribution networks.
Could the same thing happen when it comes to the power needs of the railways?
There are also issues regarding distribution of the additional power once it reaches Network Rail’s own distribution infrastructure. And even moving the existing fleet of diesel trains that currently operate on electrified routes over to electric traction would need significant reinforcements in certain areas.
As for new electrified railways, Network Rail admits that it is only at the start of the journey.
NR Chief Mechanical & Electrical Engineer Phil Doughty says: “We have undertaken some high-level desktop analysis, which assumes we follow things as outlined in the Traction Decarbonisation Network Strategy. What do we see our power demand looking like, and what additional supply points will we need?”
Once there’s more certainly about the way forward, Network Rail will look in more detail at the regional traction demand power strategies, and then forecast what enhancements to the power supply will be needed in the future.
Says Doughty: “Routes which have the more modern autotransformer systems generally have enough spare capacity. It’s more the older conventional return conductor systems where there’s not much more headroom left. We know there are some existing pinch points on our network where we have more work to do.”
Much of the long-term planning for the energy industry is carried out by the Electricity System Operator (ESO), an arm’s length company owned by National Grid. It does both short-term energy demand modelling and long-term planning.
The National Grid Electricity Transmission business takes this work annually and then feeds into the next iteration with its own thoughts. And the Transmission business is already looking at what’s needed for the railways - particularly for traction current.
Nicola Shaw, President, UK Networks at National Grid, says: “Network Rail is one of our biggest customers, so we know what they are doing and where they are going to take electricity from the system.
“We have been modelling what might happen focused on those big routes, and those are the most obvious places for upgrades. We are pretty clear about what their capacity requirements are going to be and how many sub-stations we will have to build in the 2030s and 2040s to meet Network Rail’s additional needs.
Those forecasts, according to National Grid, are based in part on assumptions about the economics of electrification vs hydrogen and battery traction.
Already there’s an emerging picture about the CrossCountry rail network, which is likely to have a mixture of some sections where battery is the best solution and in other sections overhead lines, depending on their location.
The ideal scenario would clearly be that when connected to the catenary, batteries would be topped up to then be ready to run those sections where electrification either isn’t possible or is uneconomic.
The same scenario could be the case for freight movements as well.
When it comes to actually getting the electricity lineside, Shaw says it’s already clear that there will have to be a significant upgrade of the transmission system to meet net-zero targets.
“We are going to have double the electricity flowing through the wires by 2050, but that doesn’t mean that we have to double the network. First, demand has dropped from its peak because of moves to become more energy-efficient, particularly in urban areas. There are also new technologies that are helping us manage power flows.”
National Grid also has the ability to upgrade wiring, rather than having to build new power networks.
Shaw explains: “There are a number of things you can do before you have to build more, but we certainly will have to build more.”
It’s thought that for overhead line electrification, a sub-station is needed roughly every 30 miles. Fortunately, for the railways, most towns and cities do have sub-stations, usually on the outskirts. And many of them are close to railway corridors.
For electrifying parts of the CrossCountry network in the Midlands, Richard Mann, Rail Programme Manager at the sub-national transport body Midlands Connect, says: “There’s a sub-station relatively near the railway in Oxford, there’s one relatively near the railway in Banbury, and another one near Warwick, so you kind of leap-frog from town to town. It’s all about cost, but there are enough sub-stations in the Midlands.”
However, it’s different in the North, where the railways pass through in more constrained sites and where there are more tunnels.
Another emerging option could be to use railway corridors as an additional electricity distribution network.
Shaw maintains that the electrical network that supports the railways is one of the biggest distribution networks in the UK, but it’s only set up for rail. She suggests that to gain more resilience and to get electricity to more far-reaching places, a parallel network could be built using railway corridors.
“It’s about making better use of the existing land that’s taken for infrastructure,” she says.
“At the moment, we are set up as either a rail infrastructure or electricity infrastructure operation. I think there could be some real opportunities for saying: how do we do this differently and would regulators support that?”
According to Shaw, this is already happening on the roads. National Grid is currently in discussion with Highways England, which is planning the new East Thames Crossing. This could lead to an agreement whereby special ducting is installed as part of the build which could then be used to carry electricity cables across the river.
However, when it comes to using railway land for cabling, Shaw appreciates that nothing will happen overnight. “It’s a long burn, this one,” she says.
Network Rail’s Doughty says discussions have taken place in the past but haven’t progressed much further: “The railways are very expensive corridors and most of the demand on the network is at peak times, so we have this system that could provide an opportunity to the wider transmission and distribution system.”
So, assuming that there are sufficient sub-stations and distribution solutions, there are still two other big issues going forward: firstly, the sheer quantity of electricity required to run the railway; and secondly, the costs of upgrading the network. Finding the cash is probably the biggest constraint.
Mann explains: “Typically, our railways have been built to a smaller gauge than is the standard on the continent. As a result, we are usually using the last inches to get electrification in - and often that means rebuilding half the bridge, lowering the tracks inside tunnels, and having to redo things such as drainage.”
And that, according to some, means doubling the budget for railway improvements at a time when the Government is actively looking at ways to save money.
Late last year, after previously promising record spending on infrastructure as part of the levelling-up agenda, the Government quietly removed around a billion pounds from the railway budget instead.
That decision may need to be revisited in the light of moves to decarbonise and the costs involved, which have yet to be fully quantified.
Network Rail’s Traction Decarbonisation Network Strategy puts the bill at an estimated £18 billion in the North and Midlands alone, although, as the National Infrastructure Commission pointed out in its report last year, much more detailed work is needed on costings.
Elsewhere, the Government is investing vast sums in encouraging green energy generation.
In March, ministers announced a £92 million challenge that will enable green innovators to drive forward the next generation of technologies.
The cash will be focused on three areas, including energy storage technologies, floating offshore windfarms, and biomass production.
The Government has already been providing large subsidies for the production of energy from wind, following the introduction of Feed-in-Tariffs that help to ensure that profits can be made by those investing in wind farms.
And it seems to be working. In 2019, wind power became the UK’s second largest source of electricity, providing almost a fifth of the nation’s total generation.
The Government has also been investing in nuclear power. Although its share of power generation has fallen as the older Magnox power stations have closed, construction of new facilities such as Hinkley Point C will help to increase the share into the 2030s.
The company behind Hinkley is EDF Energy.
It’s building two reactors there, and at the same time marking a significant milestone in the revitalisation of the UK’s nuclear power industry.
The arrival of Hinkley Point C will also significantly boost the output from nuclear generation, at a time when many of the current UK nuclear power stations will come to the end of their lives over the next decade.
Paul Spence, Director of Strategy and Corporate Affairs at EDF, says: “We need to run even faster to get where we need to be.
And that means building onshore wind and solar at a relatively unprecedented rate. It means massive acceleration in offshore wind building, and it means pushing on with more nuclear faster than we have done so far.”
EDF has announced the closure of three of the older advanced gas-cooled reactor nuclear power stations, with more to follow.
Construction of Hinkley Point C has now reached about the halfway stage, and the opening of the new facility will add back slightly more power generation than is being lost through the announced closures.
EDF is also in negotiation with the Government on a further nuclear power station, Sizewell C in Suffolk, which would be a direct replica of Hinkley Point C.
Spence says: “We’re hoping to see legislation later this year which would be a tangible sign of whether Sizewell C can go ahead. That would add another 3GW of capacity which would help bolster the UK’s energy security. The question of whether there’s more nuclear to follow the Sizewell C project - be it smaller modular reactors or other projects at Wylfa in Wales, in Cumbria or at Bradwell - is for the Government to decide.”
Where electrification isn’t an option, then battery-operated trains could be the answer. There are already examples of battery-powered trains in countries such as Austria and Japan, mainly running on small branch lines.
However, there is always going to be a trade-off between how much the batteries weigh and how much space on the train they take up.
Solutions include having more charging points, perhaps at the end of each branch line or even at each station.
It sounds like an ideal solution, but the more chargers you have the more costly it becomes.
There is also the issue of power supply. Most branch lines are in rural areas where the distribution network might not be up to the job, particularly where a rapid charge is required.
The faster the charge, the more power that’s needed.
One solution being looked at by Warwickshire-based Vivarail is building a charging system based around a shipping container packed with batteries that can be charged up, perhaps over a 24-hour period and even from a domestic supply if that’s all that’s available.
Vivarail Chairman Adrian Shooter says: “We spent a year going through the Network Rail approval process and our ‘Fastcharge’ system is now about to start on a year’s trial.
“The plan is to test it on a very short and undemanding branch line from West Ealing to Greenford, and that’s happening during 2022.”
Vivarail has already supplied five diesel/battery hybrid trains to the Welsh Government that can run up to 40 miles on battery.
The company is also working on a prototype train for the COP26 climate change conference in Glasgow later in the year, which could be capable of up to 100 miles under battery power.
In another sustainable twist to the story, the shipping containers could be filled with old electric car batteries that would effectively be recycled once they’re no longer usable on the road.
Trials are also taking place on Merseyside, where one of the new Stadler Class 777 trains has been fitted with battery technology for use on Merseyrail’s Northern Line. There trains are travelling up to 20 miles per run without needing to be recharged.
Network Rail is also considering the use of battery-powered trains for the 24-mile Lewes-Uckfield line in East Sussex. Its reopening plans could involve either battery propulsion or an extension of the third rail DC system.
Doughty explains: “Twenty-four miles is probably on the limit of what we believe is achievable, although battery technology is improving all the time. Even a battery train solution will require enhancement to the existing traction supply to provide sufficient capacity for charging.”
Interestingly, unlike the project on Merseyside, plans for the Uckfield line could include either static charging at either end or on-the-move charging with short stretches of track being electrified.
EDF is also going into battery technology.
In 2019, it acquired a startup company called Pivot Power, which owns several well-placed sites on the electrical transmission network where it has been installing banks of batteries to store electricity - primarily to help keep the network running during times of high demand.
But the same technology can also be used for electric vehicle charging where the network isn’t strong enough to allow it.
Spence explains: “The first of these facilities that’s up and running is in Oxford, and it’s called the Energy Super-hub. We are essentially running a wire around the Oxford Ring Road, and that also means we can help with charging at park and ride sites without the local distribution operator having to put in lots of extra sub-stations, which would be much more expensive.”
Could this be the answer to bringing down the cost of getting power to the railways in hard-to-serve areas?
It’s certainly a possibility.
As far as charging trains is concerned, Network Rail is looking at two scenarios - either static charging or charging trains on the move.
But where electrification or battery-powered traction isn’t an option, there’s hydrogen.
Last year, rolling stock leasing company Porterbrook tested its HydroFLEX train on the main line for the first time. It’s a demonstrator to prove the concept of rail-based hydrogen propulsion.
With most of the main inter-city routes likely to be electrified, hydrogen trains are likely to be deployed elsewhere - including intensive commuter routes where there are no overhead wires.
The HydroFLEX has been developed in conjunction with the University of Birmingham’s Centre of Railway Research and Education. Dr Stuart Hillmansen, who was involved in the research, says: “As part of that project, the university also worked with a number of companies developing the logistics and infrastructure around supplying hydrogen to the train.”
The ultimate aim is to use renewable electricity to produce the hydrogen through a process called electrolysis, where hydrogen is extracted from water. Although the technology has been around for some time, it’s yet to be proven at scale.
There’s also the issue of how much electricity it takes to produce the gas with an electrolyser. There are some small-scale projects ongoing, and Hillmansen says: “We’re expecting to see electrolysers all over the place eventually, but now they are just operating in a few locations. The best example is the electrolyser in Aberdeen, which has been running the buses up there for a number of years.”
Ultimately, all that’s needed is a supply of three-phase electricity and a supply of water. Hillmansen says: “Then you just bring in a containerised solution which will have an electrolyser and the compressor and hydrogen storage that’s required to fuel trains. Trains need ten times as much hydrogen as a typical bus. So, it is about increasing that capability and the scale of the operation as well.”
Hillmansen maintains that advances in hydrogen refuelling infrastructure and the capability of trains could make some electrification projects that might be planned over the next 30 years obsolete before shovels are in the ground.
He adds: “A number of railways around the world are looking at this. Many railways don’t have a high proportion of electrification. They are also looking towards decarbonisation, so it’s a global problem, even for very heavy haul railways such as you have in North America or mining operations.”
In the UK, proving the concept means first reducing the cost of making hydrogen. It’s thought that around two-thirds of the power that goes in is lost during the manufacturing process. So, is it really worth it? Wouldn’t it be better just to put up wires and send the energy directly to the trains in the first place?
Hillmansen: “It isn’t really a problem if the energy is coming from renewable sources, because then it’s just an economic argument. And if you can produce the hydrogen fuel to make the train economic to run, then you don’t really need to worry about the fact that you use more electricity than you would have if you sent it there directly.”
Using that comparison, it’s expected that when all costs are considered, some lightly used railways may well come in at a lower cost than an electrified railway, even though you’ll use more electricity.
It’s not just vehicles moving on rails that need updating to meet the 2050 target. Companies such as Network Rail have a road fleet of more than 8,000 vehicles, including cars, light goods and heavy goods vehicles.
The company has started moving away from an owned fleet to a leasing arrangement. It means that its fleet potentially will need renewing more frequently, giving an ideal opportunity to go green.
Network Rail signed the Clean Van Commitment in 2018 and is now developing a strategy to transition its road vehicle fleet to electric. It’s been working in collaboration with the Transport Systems Catapult.
A spokesman for Network Rail said: “Our sourcing team is leading on activity to support the Decarbonisation Programme, and late last year rolled out a dedicated programme across the Network Rail regions.
“There are 11 initiatives that together will significantly contribute to our carbon reduction. This includes transitioning our road fleet to electric vehicles, creating electric vehicle charging points, identifying opportunities to generate our own renewable electricity on our land, and making sure that future utility contracts are as sustainable and efficient as possible.”
And installing charge points is where companies such as Liberty Charge come in. Its business model concentrates on residential charging, particularly in areas where most houses don’t have driveways and homeowners are unable to install their own charge points.
Some companies rely on staff taking vehicles home overnight and Liberty Charge, which is using its sister company Virgin Media to deploy infrastructure, is poised to help in that respect. The company is already working with several fleet operators to identify where the charging hotspots might be.
CEO Neil Isaacson says: “What we are trying to do is get the fleet operators to work together collaboratively, to share that information. That enables companies like us to work hand in hand with local authorities.”
Liberty Charge and fleet operators all own data sets, which can help identify where EV uptake is going to be strongest. Says Isaacson: “The fleet is going to electrify first, and if we work with operators to unblock that market and understand where their drivers are going to be, and therefore where they want chargers located, then that kind of works for everyone.”
The building blocks for road and rail are now being put in place. And although progress has been slow, the pace of change is gathering.
As far as power sources are concerned, there clearly isn’t going to be a ‘one size fits all’ scenario and more development will be needed for some favoured options. It’s also not going to be cheap, with billions of pounds needing to be spent to get the railways to net zero.
And will it happen by 2050?
Perhaps, but a lot of work needs doing if that deadline is to be met.
As recent climate change reports have shown, decarbonisation must happen. And despite already being one of the most environmentally friendly ways of travelling, the railways still have a big part to play.
