Season 5 - Biogas Train
Episode 1 - Why use it on the railways?

The terraces are full. Birkenstocks are everywhere. Your Instagram is filled with stunning beaches, accompanied with ironic comments on the difficulty of office life. Yep, that’s right: summer is very much here. But as is fast becoming the norm each year, you’ll also have noticed loads of government warnings about hydration, as well as terrifying predictions from experts about wildfires and the terrifying temperatures we might see later this year.


That means it’s never been more urgent to decarbonise the transport systems we’ll be using when on holiday. In this fifth series, we’ll be taking a closer look at biogas trains. First, it’s worth noting that the transport industry represents 15 percent of greenhouse-gas emission globally and more than 30 percent in France. Meanwhile, as we explained in a previous article, the train has an exceptionally low carbon footprint compared with the plane and car. So why bother decarbonising this champion of decarbonisation? Why are so many brilliant researchers and engineers dedicating their time and energy to it? And above all, why choose biogas over another technology? Those are some of the questions we’ll be looking at today.

First off, there’s an ethical reason. Even though it may not produce as much greenhouse gas as planes or cars, trains aren’t exactly perfect. Like all other human activities, there’s a carbon footprint that needs to be lowered as much as possible. That means we shouldn’t rest on our laurels. Carrying huge numbers of people, with the lowest environmental impact possible, is a big responsibility. And the cleaner trains get, the easier it will get to transport passengers and freight without adversely affecting the planet. “Everyone agrees that the train is the most eco-friendly solution currently available to carry passengers and freight. If you want to decarbonise transport, we should be moving towards the rails and decarbonising trains”, explains Maria Lee, an expert in trains and logistics at Sia Partners. She adds: “The eco-friendly nature of the train notably stems from the fact a good swathe of the network is powered by electricity. This will increase further when said electricity is produced using renewables. The only problem is, the electrification of our train lines is extremely expensive and we don’t necessarily have the funds to pull it off. So we’ve got to find another solution.” In fact, as an expert interviewed on the SNCF website points out, every kilometre of high-speed railway costs a million euros to electrify. It’s a little less for TER trains, which, in France, represent the majority of lines running on diesel.


In the absence of sufficient funding, there remain three solutions to decarbonise the railway industry. The first is to power trains using batteries. “The idea’s simple, you charge the train using overhead lines and power it using the energy contained in the battery. Except that with current technology, they can usually only travel for 80 kilometres. In Germany, where a very regular service has been introduced, it works quite well, though the technology hasn’t been adapted to all the lines”, says Maria Lee. “As for hydrogen, it could eventually be an excellent solution. But the current economic model doesn’t seem viable. What’s more, it’s estimated that green hydrogen will only be available in sufficient quantities from 2035. Between now and then, however, we could decarbonise our systems in other ways, and definitely shouldn’t wait so long to act.

That’s where the third solution comes in: biofuels. According to Maria Lee, they can be split into two categories in the railway sector. On the one hand, you’ve got those that require agricultural land used to produce food crops. On the other, you’ve biogases, produced by the fermentation of organic waste. “The technology is well established and has been tested out in several Eastern European countries like Lithuania, Latvia and Ukraine”, adds Lee. What’s more, she says, the transition towards biogas also has the advantage of being relatively low cost (relatively speaking, as a transport policy). You simply need to adapt trains for a cost of somewhere between 200,000 and 500,000 euros per train. That’s much, much less than the electrification of a line or the purchase of new trains. “That might not suit Alstom and Siemens but it’s an excellent, transitionary solution for the short term.”

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