Shooter Urges Caution On Hydrogen Hubris
The title of this post is the same as that of an article in the January 2021 Edition of Modern Railways.
This is the first paragraph.
Vivarail Chairman Adrian Shooter has urges caution about the widespread enthusiasm for hydrogen technology. In his keynote speech to the Golden Spanner Awards on 27 November, Mr. Shooter said the process to create ‘green hydrogen’ by electrolysis is ‘a wasteful use of electricity’ and was skeptical about using electricity to create hydrogen to then use a fuel cell to power a train, rather than charging batteries to power a train. ‘What you will discover is that a hydrogen train uses 3.5 times as much electricity because of inefficiencies in the electrolysis process and also in the fuel cells’ said Mr. Shooter. He also noted the energy density of hydrogen at 350 bar is only one-tenth of a similar quantity of diesel fuel, severely limiting the range of a hydrogen-powered train between refuelling.
Mr. Shooter then made the following points.
- The complexity of delivering hydrogen to the railway depots.
- The shorter range available from the amount of hydrogen that can be stored on a train compared to the range of a diesel train.
- He points out limitations with the design of the Alstom Breeze train.
This is the last paragraph.
Whilst this may have seemed like a challenge designed purely to promote the battery alternatives that Vivarail is developing, and which he believes to be more efficient, Mr. Shooter explained: ‘I think that hydrogen fuel cell trains could work in this country, but people just need to remember that there are downsides. I’m sure we’ll see some, and in fact we should because competition improves the breed.’
i think Mr. Shooter may have made several good points.
These are my thoughts.
Creating Green Hydrogen
I haven’t done an analysis of the costs of creating green hydrogen from electrolysis, but I have a feeling, that electrolysis won’t be the only way to create large amounts of carbon-free hydrogen, in a few years.
These methods are currently available or under development or construction.
- The hydrogen tram-buses in Pau have a personal electrolyser, that provides hydrogen at 350 bar.
- London’s hydrogen buses will be provided with hydrogen from an electrolyser at Herne Bay by truck. Will the trucks be hydrogen-powered?
Some industrial processes like the Castner-Kellner process create hydrogen as a by-product.
In Shell Process To Make Blue Hydrogen Production Affordable, I describe the Shell Blue Hydrogen Process, which appears to be a way of making massive amounts of carbon-free hydrogen for processes like steel-making and cement production. Surely some could be piped or transported by truck to the rail depot.
In ITM Power and Ørsted: Wind Turbine Electrolyser Integration, I describe how ITM Power and Ørsted plan to create the hydrogen off shore and bring it by pipeline to the shore.
Note.
- The last two methods could offer savings in the cost of production of carbon-free hydrogen.
- Surely, the delivery trucks if used, must be hydrogen-powered.
- The Shell Blue Hydrogen Process uses natural gas as a feedstock and converts it to hydrogen using a newly-developed catalyst. The carbon-dioxide is captured and used or stored.
- If the local gas network has been converted to hydrogen, the hydrogen can be delivered to the depot or filling station through that gas network.
I very much feel that affordable hydrogen can be supplied to bus, train, tram or transport depot. For remote or difficult locations. personal electrolysers, powered by renewable electricity, can be used, as at Pau.
Hydrogen Storage On Trains
Liquid hydrogen could be the answer and Airbus are developing methods of storing large quantities on aircraft.
In What Size Of Hydrogen Tank Will Be Needed On A ZEROe Turbofan?, I calculated how much liquid hydrogen would be needed for this ZEROe Turbofan.
I calculate that to carry the equivalent amount of fuel to an Airbus A320neo would need a liquid hydrogen tank with a near 100 cubic metre capacity. This sized tank would fit in the rear fuselage.
I feel that in a few years, a hydrogen train will be able to carry enough liquid hydrogen in a fuel tank, but the fuel tank will be large.
In The Mathematics Of A Hydrogen-Powered Freight Locomotive, I calculated how much liquid hydrogen would be needed to provide the same amount of energy as that carried in a full diesel tank on a Class 68 locomotive.
The locomotive would need 19,147 litres or 19.15 cubic metres of liquid hydrogen, which could be contained in a cylindrical tank with a diameter of 2 metres and a length of 6 metres.
Hydrogen Locomotives Or Multiple Units?
We have only seen first generation hydrogen trains so far.
This picture shows the Alstom Coradia iLint, which is a conversion of a Coradia Lint.
It is a so-so train and works reasonably well, but the design means there is a lot of transmission noise.
This is a visualisation of an Alstom Breeze or Class 600 train.
Note that the front half of the first car of the train, is taken up with a large hydrogen tank. It will be the same at the other end of the train.
As Mr. Shooter said, Alstom are converting a three-car train into a two-car train. Not all conversions live up to the hype of their proposers.
I would hope that the next generation of a hydrogen train designed from scratch, will be a better design.
I haven’t done any calculations, but I wonder if a lighter weight vehicle may be better.
Hydrogen Locomotives
I do wonder, if hydrogen locomotives are a better bet and easier to design!
- There is a great need all over the world for zero-carbon locomotives to haul freight trains.
- Powerful small gas-turbine engines, that can run on liquid hydrogen are becoming available.
- Rolls-Royce have developed a 2.5 MW gas-turbine generator, that is the size of a beer-keg.
In The Mathematics Of A Hydrogen-Powered Freight Locomotive, I wondered if the Rolls-Royce generator could power a locomotive, the size of a Class 68 locomotive.
This was my conclusion.
I feel that there are several routes to a hydrogen-powered railway locomotive and all the components could be fitted into the body of a diesel locomotive the size of a Class 68 locomotive.
Consider.
- Decarbonising railway locomotives and ships could be a large market.
- It offers the opportunities of substantial carbon reductions.
- The small size of the Rolls-Royce 2.5 MW generator must offer advantages.
- Some current diesel-electric locomotives might be convertible to hydrogen power.
I very much feel that companies like Rolls-Royce and Cummins (and Caterpillar!), will move in and attempt to claim this lucrative worldwide market.
In the UK, it might be possible to convert some existing locomotives to zero-carbon, using either liquid hydrogen, biodiesel or aviation biofuel.
Perhaps, hydrogen locomotives could replace Chiltern Railways eight Class 68 locomotives.
- A refuelling strategy would need to be developed.
- Emissions and noise, would be reduced in Marylebone and Birmingham Moor Street stations.
- The rakes of carriages would not need any modifications to use existing stations.
It could be a way to decarbonise Chiltern Railways without full electrification.
It looks to me that a hydrogen-powered locomotive has several advantages over a hydrogen-powered multiple unit.
- It can carry more fuel.
- It can be as powerful as required.
- Locomotives could work in pairs for more power.
- It is probably easier to accommodate the hydrogen tank.
- Passenger capacity can be increased, if required by adding more coaches.
It should also be noted that both hydrogen locomotives and multiple units can build heavily on technology being developed for zero-carbon aviation.
The Upward Curve Of Battery Power
Sparking A Revolution is the title an article in Issue 898 of Rail Magazine, which is mainly an interview with Andrew Barr of Hitachi Rail.
The article contains a box, called Costs And Power, where this is said.
The costs of batteries are expected to halve in the next years, before dropping further again by 2030.
Hitachi cites research by Bloomberg New Energy Finance (BNEF) which expects costs to fall from £135/kWh at the pack level today to £67/kWh in 2030 and £47/kWh in 3030.
United Kingdom Research and Innovation (UKRI) are predicting that battery energy density will double in the next 15 years, from 700 Wh/l to 1400 Wh/l in 2-35, while power density (fast charging) is likely to increase four times in the same period from 3 kW/kg to 12 kW/kg in 2035.
These are impressive improvements that can only increase the performance and reduce the cost of batteries in all applications.
Hitachi’s Regional Battery Train
This infographic gives the specification of Hitachi Regional Battery Train, which they are creating in partnership with Hyperdrive Innovation.
Note that Hitachi are promising a battery life of 8-10 years.
Financing Batteries
This paragraph is from this page on BuyaCar, which is entitled Electric Car Battery Leasing: Should I Lease Or Buy The Batteries?
When you finance or buy a petrol or diesel car it’s pretty simple; the car will be fitted with an engine. However, with some electric cars you have the choice to finance or buy the whole car, or to pay for the car and lease the batteries separately.
I suspect that battery train manufacturers, will offer similar finance models for their products.
This paragraph is from this page on the Hyperdrive Innovation web site.
With a standardised design, our modular product range provides a flexible and scalable battery energy storage solution. Combining a high-performance lithium-ion NMC battery pack with a built in Battery Management System (BMS) our intelligent systems are designed for rapid deployment and volume manufacture, supplying you with class leading energy density and performance.
I can envisage that as a battery train ages, every few years or so, the batteries will get bigger electrically, but still be the same physical size, due to the improvements in battery technology, design and manufacture.
I have been involved in the finance industry both as a part-owner of a small finance company and as a modeller of the dynamics of their lending. It looks to me, that train batteries could be a very suitable asset for financing by a fund. But given the success of energy storage funds like Gore Street and Gresham House, this is not surprising.
I can envisage that battery electric trains will be very operator friendly, as they are likely to get better with age and they will be very finance-friendly.
Charging Battery Trains
I must say something about the charging of battery trains.
Battery trains will need to be charged and various methods are emerging.
Using Existing Electrification
This will probably be one of the most common methods used, as many battery electric services will be run on partly on electrified routes.
Take a typical route for a battery electric train like London Paddington and Oxford.
- The route is electrified between London Paddington and Didcot Junction.
- There is no electrification on the 10.4 miles of track between Didcot Junction and Oxford.
If a full battery on the train has sufficient charge to take the train from Didcot Junction to Oxford and back, charging on the main line between London Paddington and Didcot Junction, will be all that will be needed to run the service.
I would expect that in the UK, we’ll be seeing battery trains using both 25 KVAC overhead and 750 VDC third rail electrification.
Short Lengths Of New Strategic Electrification
I think that Great Western Railway would like to run either of Hitachi’s two proposed battery electric trains to Swansea.
As there is 45.7 miles pf track without .electrification, some form of charging in Swansea station, will probably be necessary.
The easiest way would probably be to electrify Swansea station and perhaps for a short distance to the North.
This Google Map shows Swansea station and the railway leading North.
Note.
- There is a Hitachi Rail Depot at the Northern edge of the map.
- Swansea station is in South-West corner of the map.
- Swansea station has four platforms.
Swansea station would probably make an excellent battery train hub, as trains typically spend enough time in the station to fully charge the batteries before continuing.
There are other tracks and stations of the UK, that I would electrify to enable the running of battery electric trains.
- Leeds and York, which would enable carbon-free London and Edinburgh services via Leeds and help TransPennine services. This is partially underway.
- Leicester and East Midlands Parkway and Clay Cross North Junction and Sheffield – These two sections would enable EMR InterCity services to go battery electric.
- Sheffield and Leeds via Meadowhall, Barnsley Dearne Valley and the Wakefield Line, which would enable four trains per hour (tph) between Sheffield and Leeds and an extension of EMR InterCity services to Leeds.
- Hull and Brough, would enable battery electric services to Hull and Beverley.
- Scarborough and Seamer, would enable electric services services to Scarborough and between Hull and Scarborough.
- Middlesbrough and Redcar, would enable electric services services to Teesside.
- Crewe and Chester and around Llandudno Junction station – These two sections would enable Avanti West Coast service to Holyhead to go battery electric.
- Shrewsbury station – This could become a battery train hub, as I talked about for Swansea.
- Taunton and Exeter and around Penzance, Plymouth and Westbury stations – These three sections would enable Great Western Railway to cut a substantial amount of carbon emissions.
- Exeter, Yeovil Junction and Salisbury stations. – Electrifying these three stations would enable South Western Railway to run between London and Exeter using Hitachi Regional Battery Trains, as I wrote in Bi-Modes Offered To Solve Waterloo-Exeter Constraints.
We will also need fast chargers for intermediate stations, so that a train can charge the batteries on a long route.
I know of two fast chargers under development.
- Opbrid at Furrer and Frey
- Vivarail’s Fast Charge, which I wrote about in Vivarail’s Plans For Zero-Emission Trains.
I believe it should be possible to battery-electrify a route by doing the following.
- Add short lengths of electrification and fast charging systems as required.
- Improve the track, so that trains can use their full performance.
- Add ERTMS signalling.
- Add some suitable trains.
Note.
- I feel ERTMS signalling with a degree of automatic train control could be used with automatic charging systems, to make station stops more efficient.
- In my view, there is no point in installing better modern trains, unless the track is up to their performance.
What Size Of Hydrogen Tank Will Be Needed On A ZEROe Turbofan?
I believe that Airbus’s proposed ZEROe Turbofan is designed for the same market segment as a A 320 neo.
- This aircraft has a fuel capacity of 26,730 litres of kerosene.
- This will have a mass of 21.38 tonnes.
- Each kilogram of kerosene can produce 46 Mega Joules of energy
- This means that full fuel tanks contain 983, 480 Mega Joules of energy.
- Each litre of liquid hydrogen can produce 10.273 Mega Joules of energy
This means that to carry the same amount of energy will need a 95,734.5 litres or 95.7 cubic metres of liquid hydrogen.
- This could be contained in a cylindrical tank with a diameter of 4 metres and a length of 7.6 metres.
- It would also weigh 6.93 tonnes.
As the range of the A 320 neo is given as 6,300 kilometres and that of the ZEROe Turbofan, as just 3,700 kilometres. the tank could probably be shorter.
Note that I used this Energy And Fuel Data Sheet from Birmingham University.
Conclusion
Carrying as much energy as an A 320 neo will be difficult.
- Range will be reduced.
- A new more efficient airframe will be necessary.
- As volume is probably more of a problem than weight, the fuselage might be lengthened by a few metres.
Designing the hydrogen system will be challenging, but I would be surprised if it were an insurmountable problem.
Could An A320 neo Be Rebuilt As A ZEROe Turbofan?
This post is a follow-up to ZEROe – Towards The World’s First Zero-Emission Commercial Aircraft.
I spent a lot of time yesterday, looking at YouTube videos of the following.
- Airbus A320 aircraft
- Airbus A 320 neo aircraft
- Airbus’s proposed ZEROe Turbofan aircraft
I also captured these profiles from the Airbus web site, of three members of the new Airbus A 320 neo family and the current Airbus A 320 ceo.
A 319 neo – Length – 33.84 metres – Max Passengers – 160
A 320 neo – Length 37.57 metres – Max Passengers – 194
A 321 neo – Length 44.51 metres – Max Passengers – 244
A 320 ceo – Length 37.57 – Max Passengers – 180
Note.
- The links on each variant lead to Airbus’s on-line specification.
- All three variants have a wing-span of 35.8 metres and a height of 11.76 metres.
- All variants have sharklets or blended winglets to improve awrodynamic efficiency.
- There are different door, cargo door and window layouts on all three variants.
- The cockpits, tail and wings look similar.
This capture from an Airbus video, shows the profile of the proposed ZEROe Turbofan.
Note, that the ZEROe Turbofan looks more streamlined than the A 320 neo family, with a redesigned nose and more swept-back tailfin and sharklets.
These are my thoughts on the current A 320 neo family and their relationship with the ZEROe Turbofan.
Focus On Commonality
For each variant on the Airbus web site, there is a section with this title. This is the first sentence for the A 320 neo.
Due to its 95 per cent airframe commonality with the A320ceo (current engine option) version, Airbus’ A320neo jetliner fits seamlessly into existing A320 Family fleets worldwide – which is a key factor for the company’s customers and operators.
Will Airbus follow this philosophy with the ZEROe Turbofan?
If it worked between the changeover between the existing A 320 fleets and the A 320 neo fleets, why change the policy?
The Cockpits
The cockpits of the A 320 neo and the A 320 ceo seem to have a similar profile, but the cockpit of the ZEROe Turbofan seems to have been reprofiled.
In ZEROe – Towards The World’s First Zero-Emission Commercial Aircraft, I showed these front on views of the cockpits of the ZEROe Turboprop and ZEROe Turbofan.
I questioned if the two cockpits were related.
- A single cockpit for both aircraft would surely ease manufacture, maintenance and pilot training.
- I’m no aerodynamicist, but it certainly looks that the new cockpit will reduce drag and fuel consumption.
Although the cockpit, appears to be being used in the ZEROe for the first time, I would expect it is already under development and might feature in any later version of the A 320 neo.
The Fuselages
The fuselage width for both the A 320 neo family and the A 320 ceo are all 3.95 metres, with a maximum cabin width of 3.70 metres.
I would expect that the ZEROe Turboprop and the ZEROe Turbofan will also use this width.
Airbus use a design called Cabin-Flex to get the most out of the interior space in the A 320 neo. This paragraph is from the Wikipedia section, that is entitled Cabin-Flex.
By permanently replacing the second door pair in front of the wing (R2/L2) with a new second pair of overwing exits, the capacity of the A321neo is increased from 220 seats to 240 seats and fuel efficiency per seat is increased by 6%, exceeding 20% together with the new engines and the sharklets. The modifications should weigh 100 kg more.[82] Initial A321neos have the A321ceo exit door configuration with four exit door pairs until the Airbus Cabin-Flex (ACF) layout can be selected.
After reading the whole section, it looks to me, that the A 320 neo fuselage is designed, to be all things to all airlines and doors and seats can be arranged to fit any requirements.
In the ZEROe Turbofan, there is a large liquid hydrogen tank behind the rear pressure bulkhead, which could be brought forward a bit to give more space and hydrogen capacity.
I suspect there will be a lot of commonality between the fuselage of the A 320 neo family and that of a ZEROe Turbofan.
I spent a lot of time, as a child building Airfix models of aircraft and it may be too much of a simplification to think of these carbon-composite airliners, as giant Airfix models.
But I wouldn’t be surprised that just like the previous generation of aluminium airliners, they can be remanufactured into something different, just like British Airways Tristars, ended up as tanker-aircraft for the RAF.
I wouldn’t be surprised to find, that later A 320 neo fuselages will be able to be remanufactured into fuselages for ZEROe Turbofans.
Comparing The Fuselages Of The A 320 ceo, A 320 neo And ZEROe Turbofan
These are the three fuselage profiles.
A 320 ceo
A 320 neo
ZEROe Turbofan
Aircraft balance on the wings, which if I remember what little I know about aircraft aerodynamics and design, apply their lift forces to the centre of gravity of the aircraft.
I know that the profile of the ZEROe is to a different scale, but three things are apparent.
- The windows at the rear don’t go as far back, as they do in the two existing designs. But then there is no need for windows around the hydrogen tank.
- The hydrogen tank could be as long as a quarter of the length of the fuselage.
- The front section of the aircraft appears longer.
The longer front section would balance the weight of the hydrogen tank.
The passengers would also help to balance the weight of the tank, by being placed further forward.
There must be the possibility of creating a larger capacity and longer range variant of the ZEROe design, by adding a larger hydrogen tank and further stretching the nose.
Airbus have been stretching these designs for years, so I suspect that they have plans for a large number of possible variants of the ZEROe Turbofan.
According to the Wikipedia entry for the A 320 neo family, there are already five civil versions of the A 320 neo; A 319 neo, A 320 neo, A 321 neo, A 321LR and A 321XLR, plus corporate and military versions.
Add in the Cabin-Flex interior and the various A320s and the ZEROe to come, must be one of the most flexible transport systems in history.
The Tailplanes
As they are of the same height and look similar, the tail sections of the A 320 neo and A 320 ceo families could be almost identical, but the tail section of the ZEROe Turbofan appears to be slightly more swept-back and perhaps more aerodynamic.
As the ZEROe Turbofan, also appears to have had a nose-job, I would suspect that Airbus have a redesigned fuselage in the works to squeeze more fuel-efficiency out of this family of already very frugal aircraft. Could this feature the more aerodynamic tailplane?
Could this advanced fuselage feature in a later version of the A 320 neo?
I also feel, that the functionality of the tailplane on the ZEROe Turbofan will need to be little different to that on the earlier planes.
- The plane is still powered by two turbofan engines on the wings.
- Rudder forces, with an engine failure on one side, will still be the same.
The big difference will be that the fuel is at the back of the fuselage rather than in the wings, which will affect the balance.
Will this effect the design of the tailplane? I don’t think it will in a large way, as Airbus seem to have lengthened the nose to compensate.
The Wings
All the wings with sharklets for the A 320 neo family and the A 320 ceo have the same wingspan of 35.8 metres, so I would expect they are all substantially similar.
But there is one big difference in that the wings of the conventionally-powered aircraft are full of fuel.
This would probably mean that much of the wing stresses in the ZEROe Turbofan would be like an A 320 neo flying with little fuel in the wing tanks. As some aircraft in the A320 neo family have fuselage tanks, Airbus can even test the wing forces and handling in a real aircraft.
But it does look that Airbus will have little trouble designing, building and certifying the wing of a ZEROe Turbofan.
There is a minor difference in that the sharklets for the ZEROe Turbofan are more extreme.
But then as I said earlier, is there a new more aerodynamic airframe for the A 320 neo in the works?
Conclusion
I very much feel that there will be a route to convert some or all of the A 320 neo aircraft to hydrogen power.