Bright spark: the future of rail electrification

Climate change will increase the frequency of flooded tracks Credit: bear_productions/Shutterstock

Transport decarbonisation is becoming ever more important, as both governments and commercial enterprises focus on reaching their sustainability goals. Rail electrification will play a key role in achieving this, and analysts forecast significant growth in this area in the coming years.

Not only does electrification help decarbonise the rail network through the removal of diesel services, but it also has the potential to enable a modal shift of freight from road to rail.

“This is where some of the most significant opportunities for transport network decarbonisation lie,” says Jonathan Ridley, Arup’s UK head of electrification.

However, the benefits of electrification go far beyond a reduction in carbon emissions. Other advantages include improved train performance through higher capacity and lower journey times, better service reliability, and reduced whole-life vehicle and maintenance costs for both rolling stock and track infrastructure. 

Governments are supporting rail electrification in several different ways. The UK, for example, has – according to the Department for Transport (DfT) – invested in the electrification of more than 1,250 miles of track since 2010, with current projects including the Transpennine Route Upgrade (TRU) – the largest undertaken by Network Rail to date – the Midland Main Line and the Severn Tunnel. In addition, £1bn of Network North funding was recently announced for electrification of the North Wales Mainline.

Across the Atlantic, there has been a step change in support for transport projects demonstrated by the passing of the Bipartisan Infrastructure Bill, which includes investing $66bn in additional passenger rail funding – the biggest investment of its kind since the creation of Amtrak.

This is supporting projects like the $2.4bn Caltrain modernisation programme (CalMod), which is one of the first US transit agencies to electrify a diesel corridor.

“Historically we’ve never seen this kind of investment in infrastructure from a federal government,” says CalMod chief officer Pranaya Shrestha.

Investments in rail electrification can be seen from China to India, and in Europe, there are many projects, many driven or supported by the EU. One example is the electrification of the 363km-long Vilnius–Klaipėda railway line in Lithuania, which is one of the more complex electrification projects of the IXB corridor of the Trans-European Transport Network.

“This was initiated to meet the objectives of the EU Green Deal and is a strategically important project for the country,” says Vytis Žalimas, CEO of LTG Infra, Lithuanian Railways’ subsidiary responsible for the country's railway infrastructure.

“Currently the line is not electrified, but this project will enable trains to run on electric traction not only in this sector but also the entire IXB corridor.”

The benefits of rail electrification are numerous, but to achieve these gains you have to overcome many challenges. From a technical point of view, these are often focused around the interface with, and impact on, existing infrastructure.

For example, CalMod is dealing with a 160-year-old railway, and the TRU is working on existing Victorian infrastructure. A common challenge is that of clearances to existing bridges and tunnels, as electrification requires more space than some of the existing infrastructure allows, particularly in smaller gauge railways like those seen in the UK.

Significant civil and structural interventions are often required, says Ridley, with associated costs and programme implications.

“Increasingly we’re seeing the use of partial or discontinuous electrification, or implementation of voltage-controlled clearance techniques to help solve these challenges,” he says.

“Secondly are the challenges of managing the electromagnetic interference risk with not only existing rail systems, requiring immunisation works for the signalling and telecoms networks but also with external sensitive receptors, including hospitals and universities.”

Finally, there’s the issue of availability and capacity in terms of bulk power supply to the rail network. “High voltage grid supply points are expensive and can take many years to plan and deliver,” Ridley adds.

Emerging technologies, such as static frequency converters (SFCs), are helping with this, allowing grid connections at more readily available lower network voltages than previously possible. These are being used by LTG Infra for the Vilnius–Klaipėda project.

“SFCs are being used on several 50Hz railways around the world. The primary drivers for switching from traditional feeder technology vary from project to project, but are generally related to feeder compliance, demand reduction, loss reduction, project capital costs, and timing of new transmission infrastructure,” says Žalimas.

“SFCs allow multiple feeder stations to be synchronised, providing financial and system reliability benefits. However, synchronised operation can introduce some technical issues not previously encountered. These include management of system resonances, implementation of control curves to optimise power flow and reduce costs, reduction of circulating power, and system congestion/failure level strategies.”

When it comes to social challenges relating to rail electrification, the main aim is to ensure local communities are onboard with what will potentially be disruptive projects.

“One of the challenges the TRU programme faces is the 70-mile route spans both rural areas and major towns and cities. Carefully managing the impact of the work on communities along the route is a significant factor in any plans that are developed,” says Ross Ashton, TRU senior sponsor.

“Overcoming issues such as this is vital, and strategic communications planning is key in doing so. For TRU, we want to embed ourselves within these communities so that they are part of the journey. To do this, we developed a sustainability strategy, referred to as ‘our guiding compass’, which focuses on local employment, apprenticeship opportunities, and community engagement.”

Community backing can also be the factor that enables a project to go ahead, as shown by the CalMod project. As a small agency, Caltrain needed the support of multiple communities in order to get the financial backing it needed from regional and national partners. These included the San Francisco County Transportation Authority, San Mateo Transportation Authority, and California High Speed Rail.

“It took a lot of effort by a lot of people. Without the support and a firm commitment from entire communities along the corridor, we wouldn’t have had access to the funds for this project,” says Shrestha.

“It takes entire communities and elected agency officials to really work collaboratively to deliver something of this magnitude on time, on budget and on schedule. Commitment from the community is really critical to successfully delivering an electrification programme.”

While support for rail electrification has grown and we continue to hear of new investments, many believe that it’s not moving fast enough.

The Railway Industry Association (RIA), for example, says work needs to be dramatically accelerated if the UK Government wants to achieve its goal of net-zero by 2050.

According to 2023 statistics from the Office of Rail and Road (ORR), only 2.2km of electrified track was added to the UK network between 2021 and 2022. This report cited that the UK’s ‘stop-start’ electrification was leading to higher costs, something that could be resolved with the introduction of a rolling programme of electrification.

“A steady, deliverable volume of electrification over the long term allows retention and development of the skills needed to deliver and enables investment in innovation and new technologies to bring down the unit rate costs and drive up efficiency,” Ridley explains.

“Without this commitment we’re likely to see those skills and investment being diverted to the emerging global opportunities.”

Clearly there’s much work to be done, but a lot of positivity can be taken in the fact that interest in, and support for rail electrification continues to grow. Hopefully the lessons learnt from each new project will lead to improved outcomes and help the rail sector get ever closer to its decarbonisation goals.

Australia could be one of the main beneficiaries of this dramatic increase in demand, where private companies and local governments alike are eager to expand the country’s nascent rare earths production. In 2021, Australia produced the fourth-most rare earths in the world. It’s total annual production of 19,958 tonnes remains significantly less than the mammoth 152,407 tonnes produced by China, but a dramatic improvement over the 1,995 tonnes produced domestically in 2011.

The dominance of China in the rare earths space has also encouraged other countries, notably the US, to look further afield for rare earth deposits to diversify their supply of the increasingly vital minerals. With the US eager to ringfence rare earth production within its allies as part of the Inflation Reduction Act, including potentially allowing the Department of Defense to invest in Australian rare earths, there could be an unexpected windfall for Australian rare earths producers.