Electrification

The complete electrification of rail networks offers several advantages, especially with regards to the reduction of emissions. Electric railways rely significantly less on non-renewable fossil fuels and generate fewer emissions over time. Electric railways also offer improved efficiency, and decreased levels of noise pollution in the areas directly around the train tracks. When trains are connected to the network they are additionally able to take advantage of power regeneration through braking, again improving efficiency and reducing energy required.

The state of rail electrification is fairly advanced, and estimates have found that 75% of passenger rail uses electricity, the other 25% relies on diesel. 60% of the European rail network is already electrified and 80% of traffic is running on these lines. According to data from Statista, Switzerland is the only European country that has electrified its entire railway network. Other countries like Luxembourg, Montenegro, and Belgium have electrified 80-90% of their network. 

China is currently undergoing a rapid electrification push, electrified railways and double-track rail is currently 86,600 and 71,800 kilometres, accounting for 68.2 percent and 56.5 percent of the country’s total railway mileage, and the country’s electric high speed rail project continues at a punishing pace. 

Latvia invested EUR 318.5 million (USD 378 million) in 2019 through the European Union Cohesion Fund, to electrify 308 kilometres of the country’s main east-west railway network.

Batteries

In progress

Hydrogen

Hydrogen competes with powered trains as an alternative to decarbonise trains in hard-to-electrify lines. However, hydrogen cannot meet the energy demands of high-speed and freight trains. For those subsectors, electrification is the only available technology. Hydrogen-powered trains can be especially popular on less travelled lines, not worth electrification, but the implementation of this technology is still important in order to move away from cars. In general, hydrogen The change to hydrogen is ideal for very old diesel trains on the non electric tracks, and may be more cost- and time-effective than building overhead lines to electrify the network. These hydrogen fuel cell trains can be built with huge hydrogen tanks so it is possible to charge them at some charging points only, which is suitable for more rural routes. It should be noted that current hydrogen technology offers much lower levels of efficiency, and at this point is much more high maintenance than other options.

Even given the limited scope of potential application there has been significant interest in the use of Hydrogen powered trains where appropriate. Between September 2018 and May 2020 Alstom, the French transport manufacturing company, conducted a 530-day trial of its Coradia iLint hydrogen powered train on the German Weser-Elbe network. From 2022, it is intended that 14 Coradia iLint trains will begin replacing the existing diesel stock in Lower Saxony. Orders for the train have now been made in France, Italy and further tests have been conducted in Austria, the Netherlands and Germany. Alstom and British rolling stock company Eversholt Rail have also lead a UK pilot project to consider the feasibility of converting existing Class 321 trains to hydrogen (which they call the “Breeze” train).

Similarly, HydroFLEX is a UK-based hydrogen train scheme run by Birmingham Centre for Railway Research and Education (part of the University of Birmingham) and railway rolling stock company, Porterbrook. One of its goals is to retrofit existing trains with the necessary equipment to run on hydrogen. Its first successful trial test took place in September 2020, where a HydroFLEX train travelled from Quinton Rail Technology Centre to Evesham and back. HydroFLEX is now working on securing its technology to the underside of carriages, so as to increase space for passengers.

Scottish Enterprise and Transport Scotland are supporting the Zero Emission Train Project to develop the use of hydrogen trains in the Scottish rail network. It aims to operate a hydrogen train on a closed rail network for showcase at COP26. Finally, the Swiss rail manufacturer Stadler has secured a contract from the San Bernardino County Transportation Authority in California to deliver the first hydrogen powered trains in the US.  

Energy efficiency

Aside from the fuel used to power the trains, increasing their energy consumption can reduce direct or indirect emissions. In most cases electricity costs are billed on the basis train weight, mileage and average consumption, which discourages energy savings for the respective train operator. As with every mode of transport, reducing emissions and increasing efficiency is of the utmost importance. Several strategies for increasing efficiency in trains and rail systems includes:

• Optimisation of timetables to maintain balanced network loads
• Timetable-based preparation time – the heating systems are switched on only in trains that will actually be utilised ahead of time. This has resulted in reduced energy consumption by 4 GWh per year in Switzerland, where such a system has been trialed.  
• Application of more efficient cooling, e.g. dry-type transformers  
• Utilisation of RCS-Modul Adaptive Lenkung (RCS-ADL), which sends suggestions to the locomotive driver concerning the optimal speed that would result in fewer stoppages and applying optimal speed from energy saving perspective. This concerns especially railways tracks utilised by numerous actors. Application of RCS-ADL in 2000 trains in Switzerland results in energy savings of 200 MWh per day.  In addition, also wear to the rolling stock is reduced improving efficiency as the system ages. 

By ensuring efficient driving practices and network usage throughout the period of service, the energy efficiency of rail systems can be maintained or increased to ensure emissions savings.

Examples:

Switzerland is known for having an efficient rail network and is continuing to make improvements yearly. Starting in 2015, Swiss Federal Railways AG (SBB) started charging locomotives equipped with individual meters only for actual energy consumption. Additionally a project which switches off heating to full carriages during peak hours to decrease energy demand recently won the Watt d’Or prize for its innovative approach to flexible consumption management. SBB also uses an adaptive control program to ensure that trains are travelling at optimal speeds to reduce waiting time, increase efficiency, and avoid conflict between trains which would increase energy demand and reduce efficiency.

Japan is perhaps the pinnacle of high speed rail, and the East Japan Railway Company (JR East) has made significant investment when it comes to promoting energy efficiency in its network. JRR East implemented an energy saving policy which centres around four pillars: increasing regenerative energy utilisation, increase renewable energy options at stations, manage energy usage at stations, and implement battery operated trains where possible. This comprehensive plan aims to meet reduction targets of -25% energy consumption and -40% carbon emissions by 2031.