The Anonymous Widower

Rail Engineer On Hydrogen Trains

This article on Rail Engineer is entitled Hydrail Comes Of Age.

It is a serious look at hydrogen-powered trains.

This is typical information-packed paragraph.

Instead of diesel engines, the iLint has underframe-mounted traction motors driven by a traction inverter. Also mounted on the underframe is a lithium-ion battery pack supplied by Akasol and an auxiliary converter to power the train’s systems. On the roof is a Hydrogenics HD200-AT power pack which packages six HyPMTM HD30 fuel cells, with common manifolds and controls, and X-STORE hydrogen tanks supplied by Hexagon xperion which store 89kg of hydrogen on each car at 350 bar. These lightweight tanks have a polymer inner liner, covered with carbon fibres soaked in resin and wrapped in fibreglass.

They have interesting things to say about the trains and the production and delivery of the hydrogen, which can be what they call green hydrogen produced by electricity generated by wind power.

This is said about supplying the hydrogen.

It takes 15 minutes to refuel the iLint, which holds 178kg of hydrogen supplied at a pressure 350 bar. It consumes this at the rate of 0.3kg per kilometre. Thus, Lower Saxony’s fleet of 14 trains, covering, say, 600 kilometres a day, will require 2.5 tonnes of hydrogen per day. If this was produced by electrolysis, a wind farm of 10MW generating capacity would be required to power the required electrolysis plant with suitable back up. This, and sufficient hydrogen storage, will be required to ensure resilience of supply.

These are the concluding paragraphs.

With all these benefits, a long-term future in which all DMUs have been replaced by HMUs is a realistic goal. However, the replacement, or retrofitting, of 3,000 DMUs and the provision of the required hydrogen infrastructure would be a costly investment taking many years.

Germany has already taken its first steps towards this goal.

For myself, I am not sceptical about the technology that creates electricity from pure hydrogen, but I think there are design issues with hydrogen-powered trains in the UK.

The German trains, which are built by Alsthom and should start test runs in 2018, take advantage of the space above the train in the loading gauge to place the tanks for the hydrogen.

Our smaller loading gauge would probably preclude this and the tanks might need to take up some of the passenger space.

But in my view, we have another much more serious problem.

Over the last twenty years, a large number of high quality trains like electric Desiros, Electrostars and Junipers, and diesel Turbostars have been delivered and are still running on the UK network.

It could be that these trains couldn’t be converted to hydrogen, without perhaps devoting a carriage to the hydrogen tank, the electricity generator and the battery needed to support the hydrogen power.

It is for this reason, that I believe that if we use hydrogen power, it should be used with traditional electrification and virtually unmodified trains.

A Typical Modern Electric Train

Well! Perhaps not yet, but my view of what a typical electric multiple unit, will look like in ten years is as follows.

• Ability to work with 25 KVAC  overhead or 750 VDC third-rail electrification or onboard battery power.
• Ability to switch power source automatically.
• Batteries would handle regenerative braking.
• Energy-efficient train design.
• Good aerodynamics.
• Most axles would be powered for fast acceleration and smooth braking.
• Efficient interior design to maximise passenger numbers that can be carried in comfort.
• A sophisticated computer with route and weather profiles, passenger numbers would optimise the train.

The battery would be sized, such that it gave a range, that was appropriate to the route.

In an article in the October 2017 Edition of Modern Railways, which is entitled Celling England By The Pound, Ian Walmsley says this in relation to trains running on the Uckfield Branch.

A modern EMU needs between 3 and 5 kWh per vehicle mile for this sort of service.

As I’m talking about a train that has taken energy efficiency to the ultimate, I think it would be reasonable to assume that 3 kWh per vehicle mile is attainable.

As I believe that most axles would be powered, I feel that it would be electrically efficient for a battery to be fitted into each car.

Suppose we had a five-car train with a 30 kWh battery in each car.

This would give a total installed battery capacity of 150 kWh. Divide by five and three and this gives a useful emergency range of ten miles.

These facts put the battery size into perspective.

• , 30 kWh is the size of the larger battery available for a Nissan Leaf.
• A New Routemaster bus has a battery of 75 kWh.

Where will improved battery technology take us in the next decade?

Use Of Hydrogen Power With 750 VDC Third-Rail Electrification

This extract from the Wikipedia entry for third-rail, explains the working of third-rail electrification.

The trains have metal contact blocks called shoes (or contact shoes or pickup shoes) which make contact with the conductor rail. The traction current is returned to the generating station through the running rails. The conductor rail is usually made of high conductivity steel, and the running rails are electrically connected using wire bonds or other devices, to minimize resistance in the electric circuit. Contact shoes can be positioned below, above, or beside the third rail, depending on the type of third rail used; these third rails are referred to as bottom-contact, top-contact, or side-contact, respectively.

If a line is powered by third-rail electrification, it needs to be fed with power every two miles or so, due to the losses incurred in electricity passing along the steel conductor rail.

I suspect that Network Rail and our world-leading rail manufacturers have done as much as they can to reduce electrical losses.

Or have they? Wikipedia says this.

One method for reducing current losses (and thus increase the spacing of feeder/sub stations, a major cost in third rail electrification) is to use a composite conductor rail of a hybrid aluminium/steel design. The aluminium is a better conductor of electricity, and a running face of stainless steel gives better wear.

Suppose instead of having continuous third-rail electrification, lengths of electrification with the following characteristic were to be installed.

• Hybrid aluminium/steel rails.
• Power is supplied at the middle.
• Power is only supplied when a train is in contact with the rail.

All trains would need to have batteries to run between electrified sections.

The length and frequency of the electrified sections would vary.

• If a section was centred on a station, then the length must be such, that a train accelerating away can use third-rail power to get to operating speed.
• Sections could be installed on uphill parts of the line.
• On long level sections of line without junctions, the electrified sections could be more widely spaced.
• Battery power could be used to take trains through complicated junctions and crossovers, to cut costs and the difficulties of electrification.
• Electrified section woulds generally be placed , where power was easy to provide.

So where does hydrogen-power come in?

Obtaining the power for the track will not always be easy, so some form of distributed power will be needed.

• A small solar farm could be used.
• A couple of wind turbines might be appropriate.
• In some places, small-scale hydro-electric power could even be used.

Hydrogen power and especially green hydrogen power could be a viable alternative.

• It would comprise a hydrogen tank, an electricity generator and a battery to store energy.
• The tank could be buried for safety reasons.
• The installation would be placed at trackside to allow easy replenishment by tanker-train.
• It could also be used in conjunction with intermittent solar and wind power.

The tanker-train would have these characteristics.

• It could be a converted electrical multiple unit like a four-car Class 319 train.
• Both 750 VDC and 25 KVAC operating capability would be retained.
• One car would have a large hydrogen tank.
• A hydrogen-powered electricity generator would be fitted to allow running on non-electrified lines and give a go-anywhere capability.
• A battery would probably be needed, to handle discontinuous electrification efficiently.
• It might even have facilities for a workshop, so checks could be performed on the trackside power system

Modern digital signalling, which is being installed across the UK, may will certainly have a part to play in the operation of the trackside power systems.

The position of all trains will be accurately known, so the trackside power system would switch itself on, as the train approached, if it was a train that could use the power.

Use Of Hydrogen Power With 25 KVAC Overhead |Electrification

The big difference between installation of 25 KVAC overhead electrification and 750 VDC third-rail electrification, is that the the overhead installation is more complicated.

• Installing the piling for the gantries seems to have a tremendous propensity to go wrong.
• Documentation of what lies around tracks installed in the Victorian Age can be scant.
• The Victorians used to like digging tunnels.
• Bridges and other structures need to be raised to give clearance for the overhead wires.
• There are also those, who don’t like the visual impact of overhead electrification.

On the plus side though, getting power to 25 KVAC overhead electrification often needs just a connection at one or both ends.

The electrification in the Crossrail tunnel for instance, is only fed with electricity from the ends.

So how could hydrogen help with overhead electrification?

Electrifying some routes like those through the Pennines are challenging to say the least.

• Long tunnels are common.
• There are stations like Hebden Bridge in remote locations, that are Listed Victorian gems.
• There are also those, who object to the wires and gantries.
• Some areas have severe weather in the winter that is capable of bringing down the wires.

In some ways, the Government’s decision not to electrify, but use bi-mode trains is not only a cost-saving one, but a prudent one too.

Bi-mode trains across the Pennines would have the advantage, that they could use short lengths of electrification to avoid the use of environmentally-unfriendly diesel.

I have read and lost an article, where Greater Anglia have said, that they would take advantage of short lengths of electrification with their new Class 755 trains.

Electrifying Tunnels

If there is one place, where Network Rail have not had any electrification problems, it is in tunnels, where Crossrail and the Severn Tunnel have been electrified without any major problems being reported.

Tunnels could be developed as islands of electrification, that allow the next generation of trains to run on electricity and charge their batteries.

But they would need to have a reliable power source.

As with third-rail electrification, wind and solar power, backed by hydrogen could be a reliable source of power.

Electrifying Stations With Third Rail

It should be noted, that the current generation of new trains like Aventra, Desiro Cities and Hitachi’s A-trains can all work on both 25 KVAC overhead or 750 VDC third-rail systems, when the appropriate methods of current collection are fitted.

Network Rail have shown recently over Christmas, where they installed several short lengths of new third-rail electrification South of London, that installing third-rail electrification, is not a challenging process, provided you can find the power.

If the power supply to the third-rail is intelligent and is only switched on, when a train is on top, the railway will be no more a safety risk, than a route run by diesel.

The picture shows the Grade II Listed Hebden Bridge station.

Third-rail electrification with an independent reliable power supply could be a way of speeding hybrid trains on their way.

Power Supply In Remote Places

Communications are essential to the modern railway.

Trains and train operators need to be able to have good radio connections to signalling and control systems.

Passengers want to access wi-fi and 4G mobile phone networks.

More base stations for communication networks will be needed in remote locations.

Wind, solar and hydrogen will all play their part.

I believe in the future, that remote routes in places like Wales, Scotland and parts of England, will see increasing numbers of trains and consequently passengers., many of whom will be walking in the countryside.

Could this lead to upgrading of remote stations and the need for reliable independent power supplies?

Conclusion

I am very much coming to the conclusion, that because of the small UK loading gauge, hydrogen-powered trains would only have limited applications in the UK. Unless the train manufacturers come up with a really special design.

But using hydrogen as an environmentally-friendly power source for UK railways to power electrification, perhaps in combination with wind and solar is a definite possibility!

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January 7, 2018 Posted by AnonW | Energy, Energy Storage, Transport/Travel | Electrification, Hydrogen, Hydrogen-Powered Trains, Innovation, Lithium-Ion Battery, Solar Power, Wind Power | 4 Comments