I've talked about these trains before, here and here, but they were previously still in test mode. Now, passenger services have started. GWR is testing them on this short stretch of track under real operating conditions, and if they work here, they will be rolled out to other branch lines where the traction is currently diesel. The discussion of the battery chemistry is interesting.
This way of reducing CO2 and diesel emissions from rail is one that could be copied by other countries, including those with bigger distances between towns, like Australia and Canada.
I talked about this before. This new video gives more useful detail.
GWR has been investigating battery-electric trains to replace diesel on branch lines.
Straight-out electrification is expensive. The overhead wires and the catenary posts are costly. On high-volume routes, this cost is worth it. But on less-used lines it is not.
On this route, the diesel train produces 960 kg of carbon dioxide vs 235 kg per day for the battery units (a 75% reduction) With renewable energy sources for the electricity, this could be reduced to 26 kg/day (a 97% reduction)
The charging rail is on the ground, but is only activated when the train is over it (much safer!)
It reaches full charge in 4 minutes (for 5 miles of travel). The charger is connected to a bank of batteries (on the ground) which is connected to the national grid. This stops the massive drain of power from tripping the local grid.
So, unlike an overhead-wire electrification, it's just one charging station, which means there is no need for catenary posts and adjacent electrical infrastructure. It's all off-the-shelf equipment, and can be installed with ease, even while services are running.
Even with current battery technology, the batteries only need to be swapped out once in the unit's operating life, and can then be recycled.
It's been tested under all sorts of conditions: rain, ice, leaves on the line, snow and baking heat, with full heating on, and it's worked without problems.
It's far more efficient than diesels in terms of power usage, with 79% efficiency, with an electricity consumption of 2.4 kW per carriage per mile, and is obviously much quieter than a diesel.
Diesels are more expensive on fuel and maintenance, but were cheapest on infrastructure. Overhead electrification was most expensive on infrastructure, but on a par with battery-trains on other costs. Costs per train-mile: £5/ train-mile, diesels £4/train-mile, battery-trains £2.52/train-mile.
The batteries have a possible range of at least 80 miles (130 km). [Though, by my calculations, that would take an hour to charge]. It is possible, though less efficient, to charge the batteries via the overhead cable, i.e., this battery-electric train could run along mixed electrified and unelectrified track.
Land transport contributes +-20% to CO2 emissions, and more to NOx, which are much more potent greenhouse gases. Cars and light trucks make up most of this, but diesel for rail is not insignificant. And it's horribly polluting.
I've talked before about bi-mode trains. Most 'diesel' trains are actually diesel-electric. A diesel generator charges batteries (in the old days, lead-acid batteries, and for all I know, that may still be the case) which then drive the electric motors which turn the wheels. Why such an apparently complicated arrangement? It's because electric motors have a higher torque than diesel motors, and can therefore accelerate away from stations more quickly. A bi-mode train is one that can, when it's possible, directly use electricity from an overhead wire or third rail to drive the engines, obviating the need for diesel; or can use the diesel engine when there is no electricity source.
There is also a battery-electric train, which is not quite the same thing. This charges up its batteries whenever there is external electricity, then uses the stored power in its batteries when the wire ends. This option, won't work, however, in places where the distance between population centres is large, such as Australia, because batteries are not yet energy-dense enough to cover long distances.
Electric traction is the "best" for trains in terms of operating cost. But the capital and maintenance costs are high, and so expanding electrification to the routes where there are only a few trains a day is not cost-effective.
In NSW, which is between California and Texas is size, the rail network within a couple of hundred kilometres around Sydney is electrified, but the majority (in terms of track, not population) of the state is served by diesel. The NSW State government has started replacing aging diesel trains with bi-mode trains, which can switch between diesel(-electric) in the countryside to electric in the city. Despite a minority of the network being electrified, the reduction in emissions is still significant.
For long routes, bi-mode traction makes sense. For shorter non-electrified routes, battery-electric makes sense. It shows you that we can cut rail emissions, if only we put our minds to it.
A “UK-first” intercity battery trial train proved that single battery technology can outperform diesel engines cost-effectively.
Hitachi Rail, Angel Trains, and TransPennine Express just wrapped up the trial, which took place in the north of England. It proved that powerful batteries offer significant benefits for emissions, fuel savings, and air quality.
Hitachi has already rolled out passenger battery trains in Japan and Europe, like the Masaccio hybrid in Italy. The intercity battery trial train in the UK demonstrated that the 700 kW battery could push the train past 75 mph and power it for over 70 km. The battery matches the weight of a diesel engine and is installed in the same undercarriage space, ensuring no risk of track degradation and no impact on the passenger environment.
The battery trial train delivered better-than-expected results in fuel savings, cutting fuel costs by 35-50%. One key way it achieved this was with an “Eco-mode” where the battery fully powered sections of the route, showing that the technology is more than ready for real-world use.
This success gives Hitachi the green light to move on to a full intercity battery-electric train, with an estimated range of 100-150 km. That would allow significant stretches of non-electrified routes to go battery-powered, avoiding the need for expensive infrastructure like overhead wires in tunnels or stations.
I put this article here because it's interesting, and suggests ways forward to cut emissions from land transport, which, including cars and light trucks, contributes roughly 20% to total greenhouse gas emissions (CO2 and nitrous oxides). But it's not very clear, and further research didn't help. For example, the writer talks about a 700 kW battery. Did they mean 700 kWh, which is the measure of stored power (for example, a typical EV has 50–70 kWh of stored electricity) or what they said, 700 kW, which is a measure of output at any moment? Also, the article gives the impression that the train was run completely on battery, than says, "“Eco-mode” where the battery fully powered sections of the route". Does this mean that some parts of the route were not fully powered by the battery, but also used diesel? Is this new train a hybrid?
Never mind. The sharp drop in fuel costs (35-50%) shows that not only is the battery technology environmentally better, but it will also save money. I've talked about bi-mode trains, which are diesel-electric when there is no overhead wire (or third rail) but switch to electric when there is an alternate power source. Adding batteries to the mix would make these trains even more flexible, and allow them to be integrated into the train network more effectively. I've also discussed battery-powered trains, here, and here. I'm also going to be doing a piece on NSW's new bi-mode diesel/electric trains. Keep an eye out for it.
I can't help thinking that a carbon tax would concentrate minds wonderfully, and we'd see much more rapid progress with battery and bi-mode trains if we had one.
Step by step we move away from fossil fuels in railways.
Electrification is overall cheaper on busy lines. To date, diesel has been cheaper on less-used lines, because the higher capital cost of installing third-rail/overhead-wire technology isn't offset by the cheaper running coats of electricity.
Which of these alternative approaches would be better would depend on distances travelled and how fast overhead catenary-charged batteries can charge. In Australia, for example, rural towns are much further apart than the towns served by this line in England, which are roughly 5 miles apart. This would require more batteries, on the train and next to the track, and more charging time.
An alternative is a locomotive which can run on either diesel or electric power, called "electro-diesel" or "bi-mode" locos (not to be confused with diesel-electric motors), such as the new trains in NSW (which I know I wrote about here on Volewica, but have been unable to find the article)
Just about everyone agrees that the best way to power a train is with electricity from overhead wires; the only problem is that it is really expensive to install. Even in Europe, which is pretty dense and has a great rail system, as much as 40% of the 25,000 miles (40,000 kilometers) of track is not electrified, and on many of these lines, the demand isn't high enough to ever justify the cost, which can be huge. There isn't only the wiring, but often all the bridges have to be rebuilt higher to handle the height of the catenary wires and pantographs on the roofs of the trains. European governments want to get rid of diesel-powered trains as part of the fight against global heating, so they have been buying hydrogen-electric multiple units (HEMU), which are electric trains powered by fuel cells running on hydrogen. But there is another player in the game: battery electric multiple units (BEMU) – trains powered directly from giant batteries, which are getting better and cheaper by the day. They are now pushing 75 miles (120 kilometers) in range; Rail Journal quotes Brahim Soua of Alstom, who says “This was not the case several years ago where the level of autonomy was close to 40km. This is thanks to an improvement in the battery’s capability to store more energy for the same mass of battery.” This is good enough range to skip through many non-electrified sections of Europe. Now Oliver Cuenca of International Railway Journal reports that the battery-powered trains cost 35% less to buy and operate than hydrogen trains. The batteries don't have to be replaced as often as fuel cells, either, so maintenance costs will be lower. Cuenca notes some caveats: However, the study assumes that only ‘green’ hydrogen made by electrolysis using electricity from renewable sources will be used. In reality, the cheaper so-called ‘grey hydrogen,’ made as a by-product of the chemical and oil industry, will be used in some cases. The problem is, there is no point in replacing the diesel trains if they run on gray hydrogen, which is made from natural gas and emits 9.3 kg of CO2 for every kg of H2 in the process. The hydrogen-hype people say this is just an intermediate step, that "The plan is that hydrogen will be produced on site via electrolysis and wind energy at a later stage of the project." But as we noted before, "while Germany's renewable electricity supply has grown dramatically, they still get half their power from coal and are closing their nuclear reactors. It will be a very long time before they are making hydrogen from electrolysis." Unless it was made at night... "The study also assumes that hydrogen will be more expensive than electricity because electricity is needed to produce the hydrogen in the first place. This may not be true, as electricity used to produce hydrogen generated at night will likely be significantly cheaper due to much lower demand compared with the daytime electricity used when most electric regional trains operate." Except that if the trains operate during the daytime, they can be charged at night with the same cheap electricity, just like people do with their electric cars. [Well, not quite: most ppl travel less than 100 km per day, while a battery electrc train could do 10-20 tmes that, so will have to charge during the day as well as overnight]And it will store a lot more of that electricity. Hydrogen is a lousy battery; the efficiency of splitting it from the oxygen is now up to about 80%. Then there are losses compressing and cooling it, and then the fuel cell is only about 50% efficient, giving an overall efficiency at the wheels of about 35%. This all might get better with improved technology, but batteries are running at 80% efficiency now[Musk has said that Tesla's batteries were 90% efficient] and they are getting better too. As energy expert Paul Martin notes, "A technology which uses 3x as much energy as its competitor, at bare minimum, will have a hard time competing—if they share the same energy source. So if H2 is going to be competitive, beware— it won't be "green" hydrogen they reach for. It'll be the only kind you can currently buy—BLACK hydrogen made from fossils without carbon capture. And that's a highly questionable way to "green" a diesel."
Trains are about to go electric. Battery-electric, that is. While electrical propulsion has been the preferred way to move trains for most of a century, the idea of moving them longer distances via battery is one that’s just now being realized. Like long-range electric cars, it’s a reality afforded by the energy density and longevity of modern lithium-ion battery packs. In Germany, where only about 40 percent of track is electrified, the trains will clean the air along routes that might have been impractical or prohibitively expensive to electrify, the state of Baden-Württemberg has ordered 20 two-car trains built in Germany by Siemens, who will oversee energy consumption and energy costs over a nearly 30-year service period. It’s the first such order for battery-electric trains for Siemens Mobility, who will deliver them by June 2023. In them, a lithium-ion battery pack is mounted under the train’s floor and is charged while it moves along via overhead lines, using them to both power the train and charge the battery. When the train reaches a stretch of rail with no overhead lines, the battery takes over. The new trains are part of Siemens’ Mireo train platform for regional and commuter rail—boasting weight reductions and improved aerodynamics. Configurations range from two to seven cars, and top speed, depending on the version, ranges from 87 to 124 mph [140 to 200 kph]. Germany and France are two markets that have started investing in battery-electric trains. Last month another company, Alstom, announced that it has a first contract to supply battery-electric regional trains for Germany’s Leipzig-Chemnitz line with three-car trains that can cover up to 75 miles and reach a top speed of 99 mph. That same company has tested hydrogen fuel-cell power as the alternate source instead of batteries. And the Canadian company Bombardier in 2018 launched the Talent 3, an electro-hybrid train that can cover up to 62 miles on non-electrified track, with a modular approach to configuring motors and batteries.
Unfortunately, none of the articles says how long it takes to charge the batteries, or, put it another way, how many k's the train must travel using the electric catenary for each k of travel under battery power.
