The Anonymous Widower

Will The Trains On High Speed Two Have Batteries For Regenerative Braking?

Regenerative braking is being fitted to most modern trains with an electric transmission.

So the proposed trains on High Speed Two will definitely use the technique.

But what will be done with the energy generated, when a train brakes?

It won’t be turned into heat, by passing the electricity through resistors on the train roof. It’s just not efficient!

Could it be returned through the electrification system to power nearby trains?

  • I think this is unlikely as you can’t always be sure there is a nearby train.
  • It also makes electrification more expensive.

So I’m pretty certain, that if possible, the energy created by braking will be stored on the train in batteries.

Modern high speed trains like Siemens Velaro have lots of powered axles, as this distributes the traction and braking forces along the train.

The AVE Class 103 is a member of the Velaro family and has these characteristics, which are given by Wikipedia.

  • Eight cars, of which six are powered.
  • Cab car length – 25.7 metres
  • Intermediate car length – 24.2 metres
  • Service speed – 310 kph
  • Capacity – 404 passengers
  • Train weight – 425 tonnes

Can this data be used to estimate the energy of a train on High Speed Two?

I will calculate the energy for an individual car.

  • I know the cab cars will be heavier, but dividing the train weight by eight should give an estimate.
  • So the car weight is 53.125 tonnes.
  • Each car will have fifty passengers.
  • So assuming each passenger weighs 90 Kg with bags etc, this gives a passenger weight of 4.5 tonnes.
  • The line speed is 400 kph.

This gives a kinetic energy for a single car of 98.8 kWh.

Bombardier Primove 50 kWh battery, which is built to power trams and trains, has the following characteristics.

  • A weight of under a tonne.
  • Dimensions of under two x one x half metres.
  • The height is the smallest dimension, which must help installation under the train floor or on the roof.

I conclude that the train designer won’t have any problems sourcing batteries with sufficient capacity to handle the regenerative braking, that can be fitted into the train.

I would distribute the batteries along the train.


July 6, 2018 - Posted by | Transport | , ,


  1. […] In Will The Trains On High Speed Two Have Batteries For Regenerative Braking?, I showed that the kinetic energy in each car of a train for High Speed Two will be about 100 kWh, when running at a full speed of 400 kph. […]

    Pingback by Thoughts On A Classic-Compatible Train For High Speed Two « The Anonymous Widower | July 6, 2018 | Reply

  2. […] Will The Trains On High Speed Two Have Batteries For Regenerative Braking?, I do a calculation for the battery size needed for a 250 mph Spanish high speed train and the […]

    Pingback by Classic-Compatible High Speed Two Trains At East Midlands Hub Station « The Anonymous Widower | May 31, 2020 | Reply

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: