Decarbonising our railways – where are we and what do we need to do next?
David Clarke, Technical Director, Railway Industry Association
Climate change increasingly dominates our news agenda – and for the rail industry, there is much discussion about how we best decarbonise the network. So what’s the current state of play for the industry and what do we need to do next?
First, it is important to note that 72% of passenger rail journeys already use electrified railways, but it is estimated by 2024 that the diesel and bi-mode passenger fleet will still be around 4,430 passenger vehicles (28% of the total fleet) plus some 750 diesel freight locomotives. Electrification is the most efficient way to operate an intensively used railway and for high speed, high intensity routes, it is the only way to decarbonise. However, we will never conventionally electrify the whole of the network and so will need other solutions to replace diesel on some lightly used routes. So, there is a real need to get this right.
When a number of electrification projects were curtailed in July 2017 due to cost and programme overruns, there was significant concern about the long term implications for reducing rail CO2 emissions. These cost overruns set the case for electrification back, but it is vital that we do not assume future projects will see the same issues as a few past ones, such as Great Western. In RIA’s view the root cause of the issues on Great Western was ‘boom and bust’; trying to accelerate into a major electrification programme after 20 years of very low activity. As our Electrification Cost Challenge Report showed, 75% of projects in the last five or so years were delivered cost efficiently and so problem projects like Great Western should not be used to estimate future costs. Drawing on evidence from RIA members and Network Rail, the report highlights lessons and best practice and demonstrates that electrification can and is being delivered at up to 50% less cost compared to past problem projects.
Next came Decarbonisation Taskforce, which was set up in March 2018 following then Rail Minister Jo Johnson’s challenge to remove diesel-only trains off the network by 2040. The conclusion in the May 2019 report by the Committee on Climate Change that the UK could become net-zero carbon by 2050 which subsequently became law, led to the taskforce also reporting on the feasibility of rail achieving this target. The final Taskforce report confirmed that achieving both these targets was feasible provided we start immediately. As a member of the Taskforce, I was pleased that the report agreed that electrification must remain top of the hierarchy for the decarbonisation of our railways.
A key recommendation of the Decarbonisation Taskforce was the creation of a delivery plan and this has already started with the Traction Decarbonisation Network Strategy (TDNS) led by Network Rail’s System Operator. It aims to identify the funding requirements and plan for technology deployment.
What do we think should be in that Study? Firstly, we want to see a rolling programme of electrification for the intensively used parts of the network. Starting this programme now will retain the experienced staff being released as the small number of current projects come to an end. The UK should aim to follow other countries’ example and aim to keep two to three delivery teams consistently in action, which would maintain a core capability in design and delivery and support a culture of continuous improvement.
Secondly, zero-carbon self-powered trains are likely to be the solution for the less intensively used parts of the network. The rail supply chain already has at least three teams working on prototypes in the UK and we can expect the first operational trials in the coming months. Moving forward what is needed are fleet orders and renewal decisions for some of the oldest Diesel Multiple Units would create the opportunity in the next few years to stimulate a market and position the UK as a leader in zero-carbon rail.
Finally, for rail to achieve its zero-carbon goals, it will be necessary to carefully manage the transition over the next 30 years. Whilst electrification is the only credible long-term solution for long-distance InterCity Type trains, bi-modes can support the transition as a rolling programme of electrification extends the ‘frontier’ of electrification each year. In the meantime however, there are many opportunities to reduce the emissions of existing diesel trains with significant remaining life. These include stop-start, exhaust after treatment, re-traction etc. These measures may be particularly useful in locations where there are air quality concerns.
Other than electrification, there are currently no viable zero-carbon alternative technologies to replace diesel in the heaviest freight locomotives, although there are options to reduce carbon including multi-engine locomotives and bi-mode locomotives. However, even if some rail freight remains diesel-powered, there is a significant opportunity to reduce net transport emissions by shifting freight to rail. Rail freight has a key role to play in the low carbon economy as rail produces 76% less carbon dioxide emissions than the equivalent road journey, meaning rail can have a much greater impact on UK carbon emissions.
It is clear that the technology the rail industry needs to decarbonise already exists. The issue is about getting started because a ton of carbon saved in 2020 is 30 times better than a ton of carbon saved in 2050. Ultimately, this will require Government and industry to think quickly and strategically about the roll out of electrification and new forms of clean traction. We look forward to seeing Network Rail’s Decarbonisation Study, when its published in the summer. Given clear government support we expect this will give the clarity that will allow the industry to invest and meet the rail decarbonisation challenge.