Thoughts On Batteries
As a Control Engineer, I have a lot of thoughts about making the World a more efficient and safer place.
As a simple example of what Control Engineering is all about, do two hundred mile drives in your car.
- One is a route you don’t know.
- The other is one you know very well.
In both journeys drive as carefully as you can to try to do both journeys using the minimum amount of fuel.
Inevitably, in most cases, you will do the second route on less fuel, because you will adjust speed and anticipate possible problems from previous knowledge.
A well-designed control system for a self-driving car should be able to outperform a manually-driver car because it has better knowledge.
Control Engineering is all about taking all the knowledge you can, processing it in a control system or computer and doing the job to the ultimate best.
Batteries Will Get A Higher Charge Density Per Cubic Metre And Per Dollar
There are a lot of clever engineers and scientists out there in countries like China, Germany, Japan, Korea and the USA, working on battery technology and increasing the charge density will be one of their key objectives.
The smaller and more affordable a battery becomes, the more will be sold.
With several large companies out there investing heavily in the production of batteries, there can only be one ultimate wuner – the individual, company, government or organisation, who eventually pays for the product in which the battery is installed.
So How Will Control Engineering Be Involved?
In some ways, it already is!
Control Engineering In Personal Devices
In your smart-phone, laptop or personal device, you can set parameters to get the maximum minutes for one charge of the battery.
You are effectively, tweaking the device and the battery control system is doing the best it can with the lkimited energy resources of the battery of the device.
Control Engineering In Transport Systems
One of the problems with personal devices, is they need to be plugged in to be charged.
But as transport systems are larger and often have access to other forms of energy, recharging is not such a problem.
- Batteries in hybrid vehicles can be charged by an onboard engine.
- Some battery and hybrid cars can be plugged into the mains.
- Braking energy can be recovered and used to charge the battery.
- Trains, trams and trolley-buses can use overhead wires or third-rail systems to charge the battery.
It is the major task of the vehicle’s control system to balance the needs of traction and the onboard systems, by pulling in energy from various sources.
A Typical Hybrid Bus
A hybrid bus like a Routemaster, has a very different transmission system to your bog-standard diesel bus.
- It is actually driven by a Siemens ELFA2[4]electric traction motor.
- Braking is regenerative.
- The Cummins diesel engine is mounted under the rear stairs.
- The 75 KwH battery is mounted under the front stairs.
Effectively, the diesel engine tops up the battery to a high enough level and the wheels are driven from the battery.
The control system manages the energy starting and stopping the engine as required.
The Ultimate Hybrid Bus
In the ultimate hybrid bus, the control system would know lots of other factors, including.
- The route.
- The actual and expected number of passengers.
- The actual and expected weather.
- Whether Arsenal were plying at home, or there was a demonstration by taxi-drivers.
So it would manage the power in the battery according to the predicted future energy requirements.
What would that do for fuel economy and the reduction of pollution?
But how could the efficiency of the bus be improved further?
- A lighter battery with the same capacity.
- A lighter diesel-engine, traction motor and other components.
- A much improved control system.
As with most things, reducing weight is probably the most important. But don’t underestimate, what can be achieved with the ultimate control system.
It all points to my belief, that we should probably leave the development of batteries to the big boys and concentrate on the applications.
Hybrid Electric Trucks
Hybrid electric trucks are on the way.
Hybrid Trains And Trams
I think the mathematics point to hybrid trains and trams being one of the better applications of batteries in transport.
A typical four-car electric multiple unit like a new Class 710 train, weighs about 130 tonnes or 138 tonnes with passengers. Going at a line speed of 100 kph, it has a kinetic energy of 15 KwH. So this amount of kinetic energy would be well within the scope of a 75 KwH battery from a Routemaster bus.
I think that the typical four-car electric multiple unit can easily be fitted with a battery to handle the braking for the train.
The physics of steel-wheel-on-steel-rail are also very efficient, as Robert Stephenson, if not his father, would have known.
But with trains, there are several ways the batteries can be charged.
- From 25 KVAC overhead power.
- From 750 VDC third-rail power.
- By recovering braking energy.
- From a small diesel generator.
A good control system manages the energy and also raises and lowers the pantograph as needed.
Conclusions
Design and manufacturing competition from the big players in batteries, will bring the price down and increase the amount of energy that can be stored in a battery of a particular size.
But the key to making the most out of a battery is to have a well-designed control system to manage the energy.
Theresa Mentions The B-Word
On today’s Andrew Marr Show, Theresa May has just said that she has setup a review into battery technology.
I can’t find anything else.
However, I did find this snippet in The Sunday Times, when I bought the paper.
Ministers will pledge to invest in digital, energy, construction and transport infrastructure in each region. Funding is already earmarked for an institute to develop new battery technology.
That is probably something we need.
Why Not Hydrogen-Powered Trains?
I regularly use the London bus route RV1 which runs along the South Bank between Tower Gateway and Covent Garden.
This article on the Rail Engineer web site is entitled And now Hydrogen Power – Alstom’s new fuel cell powered train.
The article is worth reading and gives a good review of what might be possible with a hydrogen-powered train.
I have a couple of reservations about hydrogen-powered vehicles.
- In the late 1960s, I worked at ICI Plastics. The Division had had a serious accident with a polythene plant a couple of years previously and there was a distinct lack of enthusiasm for highly-compressed flasmmable gases, that I share to this day.
- I also feel that, if the technology is so good, why aren’t all city buses and taxis hydrogen-powered?
Hydrogen could be the fuel of the future, but we’re possibly nowhere near its time.
This is an extract from the article.
The efficiency of the system relies on the storage of energy in the lithium-ion batteries. Fuel cells tend to work at their best if they are run continuously at reasonably constant performance. The battery stores energy from the fuel cell when not needed for traction and from regenerative braking when the train’s motors turn kinetic energy into electrical energy. In short, the batteries store the energy not immediately required, in order to supply it later, as needed.
So wouldn’t it be better to have a decent charging system for the batteries?
- Overhead electric
- Protected third rail electric
- Small diesel engine.
A system appropriate to the location could be used.
Meet Coventry’s Battery Boffin Taking On Tesla
This is the title on an article in the Business section of The Sunday Times.
Read it, but if you can’t here’s a quick summary.
- Professor David Greenwood at the Warwick Manufacturing Group is developing a battery for Jaguar and Land Rover.
- Plans are afoot to build a massive battery factory in Coventry.
- Greenwood and his team are working to give the Nissan Leaf more range and a more affordable battery.
I don’t believe that the team in Coventry are the only group in the world with similar aims.
Note that in How Big Would The Batteries Need To Be On A Train For Regenerative Braking?, I reckoned that one battery from a Nissan Leaf could handle the regenerative braking energy of a four-car Class 710 train, running between Gospel Oak and Barking.
We are approaching the era of battery transportation at a fast pace.
Japanese Trains With Batteries
If Bombardier in Derby and the Germans in Chemnitz (Karl Marx Stadt to Jeremy and the Corbedians) are addressing battery technology, you could be sure that the Japanese would have ideas and there is this article in Railway Gazette, which is entitled Emergency batteries for Tokyo Metro trains.
This is said.
Nippon Sharyo Series 1000 trainsets operating on Tokyo Metro’s Ginza Line have been fitted with Toshiba onboard emergency batteries so that they can reach the next station under their own power in the event of a traction supply failure.
Toshiba says the SCiB lithium-ion battery is well-suited to emergency use, being resistant to external shock, internal short circuits and thermal runaway. It recharges rapidly, has a long life and a high effective capacity over a wide range of environmental conditions.
The battery draws power from the third rail during normal operation, and can supply the traction system in the event of power outage or other emergency. It can also be used for train movements within depots.
I also said this in Bombardier’s Plug-and-Play Train,
I wouldn’t rule out that all Class 345 trains were fitted with some form of onboard energy storage.
The main reasons are all given in the article about Japanese trains.
German Trains With Batteries
One of my Google alerts found this article on Rail Journal, which is entitled DB to convert DMUs to bi-mode hybrid trains.
This is said.
GERMAN Rail (DB) has announced it is working with technical universities in Chemnitz and Dresden to develop bi-mode (diesel and electric) trains with lithium-ion battery storage. Between 2017 and 2021 DB intends to convert 13 existing Siemens class 642 Desiro Classic DMUs to hybrid bi-mode configuration.
It seems the Germans share my belief that trains with batteries are the future.
How Big Would Batteries Need To Be On A Train For Regenerative Braking?
Let’s assume that we have a Class 710 train, trundling around North East London at up to 120 kph.
To calculate the kinetic energy in the train, which will have to be transferred to the battery, we need the mass of the train and its velocity.
I’ll start with the velocity of the train.
As it approached a station, it will be at whatever is the appropriate line speed, which to make things easy I’ll assume is 100 kph or just under 28 metres per second.
In most cases after stopping and discharging and loading a few passengers, it will probably return to a similar line-speed to go to the following station.
The mass of each car of an Aventra, is found at several places on the Internet, including this entry in Wikipedia which gives it as 30-35 tonnes. So the four-car Class 710 train could have a mass of 130 tonnes. Add 100 passengers at an average of 80 kg. each and this would make the mass 138 tonnes
Applying the standard formula gives a kinetic energy of 53240741 joules or in common-or-garden units 14.8 kilowatt hours. So the energy of an Aventra going at 100 kph could power a one bar electric fire for fifteen hours.
To get a better handle on how much energy is involved let’s look at these specifications for a Nissan Leaf car.
Nissan talks about 24 and 30 kWh versions of the car, So if this is the battery size, then one of Nissan’s batteries could store all the braking energy of a four-car Class 710 train.
Even a fully-loaded Class 345 train would only need a 50kWh battery.
Assuming of course, I’ve got the maths correct.
I have a feeling that using batteries to handle regenerative braking on a train could be a very affordable proposition.
As time goes on, with the development of energy storage technology, the concept can only get more affordable.
Where Are The Battery Trains? – Part 2
My Trip To Corby today got me thinking more about the reasons for the non-appearance of IPEMUs, that I wrote about in Where Are The Battery Trains?
I have released several software products in my time and I’ve made certain that when I do this, that the product is fully tested and up to the job.
I suspect that Bombardier are no different, except they are probably a lot more thorough!
Testing The IPEMU And The Batteries
This article in Rail Technology Magazine is entitled Bombardier enters key analysis phase of IPEMU and it goes on to describe the sort of work being done. This is said.
Engineers in Mannheim are comparing four battery types, including the Valence batteries used on the demonstrator.
“What we’ve seen from the trial is that there is some work that we’ve still to finish on understanding the number of batteries that we apply for a particular performance,” he said. “We are looking at the packaging design in terms of how we pack the batteries together and how we monitor the overall temperature of the batteries for service. This is all to do with closing the triangle.”
I suspect most of this battery testing is being done on an off-train test rig, as if you have at least one rig for each battery type, testing can be done in parallel.
These rigs would be fairly simple affairs, where a computer with the route profile cycles the batteries through what they’d go through on an actual train, again and again.
I wouldn’t be surprised if this testing has widened, as obviously they are looking for a battery system with these characteristics.
- Very high reliability.
- The ability to hold as much energy as possible.
- A size and weight, that would enable a complete battery to be under the floor of a train.
- An acceptable cost.
Bombardier have not said, whose batteries they are testing, except that the ones they used in the prototype from Valence are on the list.
But supposing a reputable company, came to Bombardier and said, they could modify the batteries they’ve used successfully in such-and-such an application, do you think Bombardier would dismiss them out of hand?
Of course they wouldn’t!
I think that if the IPEMU gets introduced into service, that there could be a surprise in the type and manufacturer of the batteries.
Battery Choice Before Manufacture
Some battery types would inevitably be better than others and the testing would obtain a packaging design, range and cost for each design.
The big problem for the trains, is that until you decide on the type of battery to use, you can’t finalise the design of the battery pack and start manufacture.
This testing could throw also up strengths as well as problems.
The Problem Of Range
Range on batteries, is very important, as the longer it is, the more routes become possible for an IPEMU.
I was told on the Class 379 demonstrator, that a range of sixty miles was possible with that train. In this document on the Bombardier web site, this is stated about the objectives for the IPEMU.
The target is to operate a 185 tons four-car BOMBARDIER* ELECTROSTAR* train on battery up to 120 km/h for a distance of up to 50 km, which requires battery capacity in the range of up to 500 kWh. The design solution charges the batteries with the existing line converter equipment and connects the motor converters to the batteries when the 25 kVAC overhead line is not available. The lithium-ion batteries weigh less and can charge more quickly than industrial-form batteries, such as those used in automobiles.
Hard evidence of the actual range is difficult to find, although the figure of sixty miles is quoted in this section in Wikipedia.
I will now look at four longer routes, where the IPEMU may be the solution.
1. St. Pancras to Corby and Oakham
In my trip today to Corby, I saw how Network Rail are creating a fast route to the town, which it looks like will be double-track all the way to Oakham, This would include the route over the Welland Viaduct, which would be the sort of electrification, that would be difficult for engineering, aesthetic and heritage reasons.
Given that North Northamptonshire and the surrounding area, is going to see the development of several thousand houses, it would seem to me that an ideal IPEMU should be able to reach at least Oakham from St. Pancras. As Corby is about thirty-two miles and Oakham is forty-six miles from Bedford, this would mean that to provide a service would need a IPEMU with a range of sixty-four miles to reach Corby and ninety-two to reach Oakham, respectively.
So on the face of it, Corby and Oakham would be out of the range of a train fitted with the original Valence battery pack with its range of sixty miles, unless there was some electrification onwards from Bedford.
Yesterday, I saw that the piles for the electrification were going in North of Bedford. A rough calculation shows that for a sixty mile range IPEMU to reach Corby would need tjust a few miles of electrification North from Bedford. Oakham would need nearly twenty.
2. Liverpool Street to Lowestoft
Another route talking about as an IPEMU prospect is the East Suffolk Line between Ipswich and Lowestoft. This would need a train with a range of ninety-eight miles.
But as from Bedford, there could be a section of electrification at the Southern end of the line near Ipswich and perhaps some method of charging the train at Lowestoft.
3. Paddington to Bedwyn, Newbury and Oxford
Ever since I wrote Rumours Of Battery Powered Trains, which was based on an article in the September 2015 edition of Modern Railways, which was entitled Class 387s Could Be Battery Powered, I have believed that the Thames Valley could see several service run by IPEMUs.
I wrote this in a letter to a railway magazine in a letter entitled Class 387 IPEMUs to Oxford.
This sounds like an impossible dream, but if you were running Great Western Railway, you need some crumb of comfort, to cope with the arrival of Chiltern Railways at Oxford station in December 2016.
In September 2015, there was an article in Modern Railways with the headline of Class 387s Could Be Battery Powered, that described how GWR were thinking of creating some Class 387 IPEMUs.
In April 2016 the same magazine stated that electrification to Maidenhead could be ready before the end of 2016.
So that would enable Class 387 IPEMUs to reach Reading, Henley and Marlow, by doing the last few miles on batteries.
Also min the same issue of the magazine, Roger Ford also reported that the Reading to Didcot test track could be electrified by the end of the year.
As Didcot to Oxford and back, should be within the range of a Class 387 IPEMU running on batteries, I wouldn’t be surprised to see an electric service to Oxford before 2017.
I think it is true to say that this scenario is helped by every small extra morcel of range.
4. Basingstoke to Exeter
This section of the West of England Main Line is always being touted as needing electrification, but this section at nearly a hundred and thirty-five miles is certainly too long for a first-generation IPEMU.
On the other hand, selective short section of third-rail electrification, might make this route possible.
Note.
- These four routes would give significant advantages to operators, with faster electric services to London and in the case of Oakham and Exeter, they would release high-quality diesel multiple units to provide other services.
- As all of these routes are over sixty miles, it shows how, advances in battery design, which might bring increased capacity could increase the places where IPEMUs could provide an electric train service.
So are Bombardier’s engineers working on battery designs, that will handle as many routes as possible, that would be worthwhile to run with IPEMUs?
Other Technology
I am of the opinion that other technologies will stretch the range and applications of IPEMUs.
- Automatic control of the pantograph up and down at line speed would surely be important.
- Short sections of electrification in stations, where the trains stop.
- Various aids would probably help the driver make the most of the battery capacity.
- Improved signalling and track.
I am strongly of the opinion, that we’ll see a constant improvement in the range of an IPEMU.
Conclusion
I have only talked about medium length routes in the range of upwards of sixty miles.
If you add in all of short distance uses on branch lines, I think we’ll be seeing a lot of IPEMU-equipped trains in the future.
Their current non-appearance, may just be that Bombardier want to get the train absolutely right.
If they do that and the financial case stacks up, then Bombardier could see orders for a lot of new trains.
Batteries Or Flywheels?
Hybrid buses and IPEMU trains need some form of energy storage.
Typical systems generally use batteries. Mechanical devices are discussed in this article in Transport Engineer.
Read the article.
The Aussies Get Into Home Batteries
As you might imagine, Australia with its sunshine and lots of remote communities could be a big market for battery technology like Tesla’s Powerwall. But this article in the Australian Financial Review shows why the country will be a big market.
It says that for example in Queensland, a third of the houses have solar panels, which must only increase the demand for batteries.
But it also says that the way the Australians charge for electricity is different to the United States and this makes batteries much more useful. I think that in the UK, we follow the Australian model. Except for the sun of course!
The article has some interesting details on how the price of the devices will go, especially as it says that Panasonic who are one of the Big 3 battery makers will be entering the market soon.
I all think it goes to show that each market is different and I suspect that the UK market will be different again, as most of us don’t live in houses that are too friendly to solar panels.
But my house is with its flat roof, and I am watching the price of solar panels, because I reckon in the next few years, I’ll be able to fit a very affordable system, that will take me substantially off-grid, with a battery in the garage.
Solar panels, battery technology and small innovative energy companies are going to give the Big 6 energy companies, one hell of a kicking.
The Anonymous Widower 