The Anonymous Widower

Thoughts On Batteries On A Hitachi Intercity Tri-Mode Battery Train

This Hitachi infographic describes a Hitachi Intercity Tri-Mode Battery Train.

Hitachi are creating the first of these battery trains, by replacing one of the diesel power-packs in a Class 802 train with a battery-pack from Hyperdrive Innovation of Sunderland.

This press release from Hitachi is entitled Hitachi And Eversholt Rail To Develop GWR Intercity Battery Hybrid Train – Offering Fuel Savings Of More Than 20%, gives a few more details.

The Class 802 train has the following characteristics.

  • Five cars.
  • Three diesel power-packs, each with a power output of 700 kW.
  • 125 mph top speed on electricity.
  • I believe all intermediate cars are wired for diesel power-packs, so can all intermediate cars have a battery?

In How Much Power Is Needed To Run A Train At 125 Or 100 mph?, I estimated that the trains need the following amounts of energy to keep them at a constant speed.

  • Class 801 train – 125 mph 3.42 kWh per vehicle mile
  • Class 801 train – 100 mph 2.19 kWh per vehicle mile

The figures are my best estimates.

The Wikipedia entry for the Class 800 train, also gives the weight of the diesel power-pack and all its related gubbins.

The axle load of the train is given as 15 tonnes, but for a car without a diesel engine it is given as 13 tonnes.

As there are four axles to a car, I can deduce that the diesel power-pack and the gubbins, weigh around eight tonnes.

How much power would a one tonne battery hold?

This page on the Clean Energy institute at the University of Washington is entitled Lithium-Ion Battery.

This is a sentence from the page.

Compared to the other high-quality rechargeable battery technologies (nickel-cadmium or nickel-metal-hydride), Li-ion batteries have a number of advantages. They have one of the highest energy densities of any battery technology today (100-265 Wh/kg or 250-670 Wh/L).

Using these figures, a one-tonne battery would be between 100 and 265 kWh in capacity, depending on the energy density.

As it is likely that if the diesel power-pack replacement would probably leave things like fuel tanks and radiators behind, so that the diesel engines could be reinstalled, I would expect that a battery of around four tonnes would be fitted.

On the basis of the University of Washington’s figures a 400 kWh battery pack would certainly be feasible.

Using. the energy use at 100 mph of 2.19 kWh per vehicle mile, I can get the following ranges for different battery sizes.

  • 400 kWh battery – 36.53 miles
  • 500 kWh battery – 45.67 miles
  • 600 kWh battery – 54.80 miles
  • 800 kWh battery – 73.06 miles

As Lincoln and Newark are just 16.6 miles apart, it looks to me that a 500 or 600 kWh battery could be a good choice for that route, as it would leave enough hotel power for the turnround.

It should also handle shorter routes like these.

  • Newbury and Bedwyn – 13.3 miles.
  • Didcot and Oxford – 10.3 miles
  • Newark and Lincoln – 16.6 miles
  • Leeds and Harrogate – 18.3 miles
  • Northallerton and Middlesbrough – 20 miles
  • Hull and Temple Hirst Junction and Hull – 36.1 miles

Some routes like Temple Hirst Junction and Hull would need charging at the destination.

The Range Of A Five Car Train With Three Batteries

Suppose a Hitachi Intercity Tri-Mode Battery Train had three battery-packs and no diesel engines.

  • It would be based on Hitachi Intercity Tri-Mode Battery Train technology.
  • It would have two driver cars without batteries.
  • It would have three intermediate cars with 600 kWh batteries.
  • It would have 1800 kWh in the batteries.
  • The train would be optimised for 100 mph running.
  • My estimate says it would need 2.19 kWh per vehicle mile to cruise at 100 mph.

It could have a range of up to 164 miles.

If the batteries were only 500 kWh, the range would be 137 miles.

The Ultimate Battery Train

I think it would be possible to put together a nine car battery-electric train with a long range.

  • It would be based based on Hitachi Intercity Tri-Mode Battery Train technology, which would be applied to a Class 800 or Class 802 train.
  • It would have two driver cars without batteries.
  • It would have seven intermediate cars with 600 kWh batteries.
  • It would have a total battery capacity of 4200 kWh.
  • The train would be optimised for 100 mph running.
  • My estimate in How Much Power Is Needed To Run A Train At 125 Or 100 mph?, said it would need 2.19 kWh per vehicle mile to cruise at 100 mph.

That would give a range of over 200 miles.

If the batteries were only 500 kWh, the range would be 178 miles.

Aberdeen, Inverness, Penzance and Swansea here we come.

Can Hitachi Increase The Range Further?

There are various ways that the range can be improved.

  • More electrically-efficient on-board systems like air-conditioning.
  • A more aerodynamic nose.
  • Regenerative braking to the batteries.
  • Batteries with a higher energy density.
  • Better driver assistance software.

Note.

  1. Hitachi have already announced that the Class 810 trains for East Midlands Railway will have a new nose profile.
  2. Batteries are improving all the time.

I wouldn’t be surprised to see a ten percent improvement in range by 2030.

Conclusion

I was surprised at some of the results of my estimates.

But I do feel that Hitachi trains with 500-600 kWh batteries could bring a revolution to train travel in the UK.

Edinburgh And Aberdeen

Consider.

  • The gap in the electrification is 130 miles between Edinburgh Haymarket and Aberdeen.
  • There could be an intermediate charging station at Dundee.
  • Charging would be needed at Aberdeen.

I think Hitachi could design a train for this route.

Edinburgh And Inverness

Consider.

  • The gap in the electrification is 146 miles between Stirling and Inverness.
  • This could be shortened by 33 miles, if there were electrification between Stirling and Perth.
  • Charging would be needed at Inverness.

I think Hitachi could design a train for this route.

 

May 31, 2021 - Posted by | Transport | , , , , , , ,

6 Comments »

  1. Energy will be needed to accelerate the train in the first place as well as supporting hotel load so frequency of stops will affect overall consumption per mile. i reckon they will need to fast charge at terminus but hopefully be able to use existing traction inverters to do that otherwise more kit to lug around.

    Comment by Nicholas Lewis | May 31, 2021 | Reply

  2. Hitachi have designed the trains for regenerative braking and I’m certain that will be used to charge the batteries.

    Note that my estimate for the amount of electricity the train used came from the original specification, so I don’t think it’s that far out.

    I also know of at least three sensible methods of charging the trains in stations.

    I suspect the cheapest way to charge them would be to put up a small amount of electrification. This would also help accelerate the train away from the terminus.

    Comment by AnonW | May 31, 2021 | Reply

  3. Not sure of the weight of “the gubbins”, but this would be traction motors, gearbox, drive shafts etc.
    The line from Perth to Inverness is long and hilly, but regeneration would recoup some of the energy required and with the quite low speed limit, less would be needed anyway.
    Any train on this line needs to have enough hotel power to be able to survive being stranded overnight, as has happened.
    Maybe GBR should talk to the Swiss?

    Comment by R. Mark Clayton | May 31, 2021 | Reply

    • traction motors, gearbox and drive shafts will be needed for electric operation. I suspect they’d leave the fuel tank and the radiators. I suspect that Hyperdrive are a devious bunch of engineers, so if the battery packs need cooling, they’ll plumb into MTU’s bits.

      Remember, I’ve been in the cab of a HST between Edinburgh and Inverness. Regenerative braking and automatic train control would speed it through the Highlands.

      Comment by AnonW | May 31, 2021 | Reply

  4. […] article is a repeat of Thoughts On Batteries On A Hitachi Intercity Tri-Mode Battery Train, but for their other train with batteries; the Hitachi Regional Battery […]

    Pingback by Thoughts On Batteries On A Hitachi Regional Battery Train « The Anonymous Widower | June 1, 2021 | Reply

  5. […] Thoughts On Batteries On A Hitachi Intercity Tri-Mode Battery Train, I had a section, which was called The Ultimate Battery […]

    Pingback by What Would Be The Ultimate Range Of A Nine-Car Class 800 Train? « The Anonymous Widower | June 2, 2021 | Reply


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