The Anonymous Widower

Skeleton To Supply Ultracapacitors To CAF

The title of this post, is the same as that of this article on Electrive.

These two sentences are in the last paragraph.

In its German plant in Großröhrsdorf, Skeleton Technologies is working on so-called hybrid energy storage systems. In short, the advantages of lithium-ion batteries (high energy density) are to be combined with the advantages of ultracapacitors (high performance, long service life) in such hybrid storage systems

But I suggest you read the article as it indicates how supercapacitors could be used on battery-trams and trains.

If CAF use supercapacitors on their trains it will not be their first application on heavy rail in the UK. In Brush Traction Signs Contract With Skeleton Technologies For Modules For Class 769 Trains, I describe how supercapacitors are used to start the engines.

September 3, 2021 - Posted by | Transport/Travel | , , , ,


  1. Caf have been using supercaps in their trams in Zaragoza for many years – albeit only for the wires-free 2km in the city centre. More ambitious is Alstom’s system in Nice, running between the airport and the centre, which I’ve been on several times (pre-Covid). for lots of videos. The supercaps can be charged in seconds from a 3rd rail at each stop, and that provides sufficient power to get the tram to the next stop.

    Skeleton’s not the only company looking to expand the use of supercaps. I keep a watch on the French company NAWA who are looking to start mass production next year They’re also looking to combine supercaps and batteries – it should be possible to charge the supercaps in seconds and then charge batteries from them for a much longer range. Likewise US and Japanese companies I’m aware of.

    We will see what the next few years bring. I think a lot of people will be very surprised at what various types of energy storage can achieve.

    Comment by Peter Robins | September 3, 2021 | Reply

    • All of the developments of which this is just one path illustrate how careful you have to be about investing in new vehicles and infrastructure electrification at the moment. If I were buying rolling stock at the moment I’d be looking to hedge against the sort technical obsolesence I saw as traction systems transitioned from DC to AC by the evolution of various high powered semiconductor devices. I’m sure manufacturers love the current situation but the public purse won’t.

      Comment by fammorris | September 4, 2021 | Reply

      • I think those buying trains have to make sure the contracts include updating batteries or other tech as newer versions become available. This ought to be simple with the modular designs trains have nowadays. Trains last for 30 years or so, and it’s a certainty that batteries will change substantially over that time.

        The Commons Select Committee in their recent report recommended that decarbonisation plans/strategies should be reviewed on a regular basis, and take account of advancing technologies. I think that’s sensible.

        Comment by Peter Robins | September 4, 2021

      • just to follow up on the subject of replacing batteries, I see that Chinese EV maker NIO has just opened their first venture into Europe, in Norway (by far the highest EV penetration in Europe) This includes their Battery as a Service feature, where you pay separately for batteries and can opt to replace the battery entirely, which takes about 5 mins, instead of recharging. This means a new improved model can be installed as part of your contract with the company. Implementing something similar for trains (and buses) should be straightforward, as most trains sit around in depots overnight, where a new battery could easily be fitted given appropriate equipment. A trend to watch, I think.

        I also see NIO are planning to introduce a solid-state battery in 2023. We will see.

        Comment by Peter Robins | October 1, 2021

    • I’m glad that Skeleton Technologies have been highlighted with their development of the hybrid capacitor solid state battery. Looking at the majority of other interested parties (Samsung, LG, NEC, Hitachi, CATL etc.) their emphasis appears at present to be focussed solely on the solid-state battery, in other words Skeleton have jumped this interim phase.
      I know that sensible recommendations have been made for technology have been made, I equally know from the BEIS Hydrogen Strategy what a pig’s ear the government are making despite informed opinion.
      Issues around the controls on the dynamic evolution of battery technology regarding second usage are well referenced in the following

      Comment by fammorris | September 5, 2021 | Reply

  2. I was very much involved as a fifteen and sixteen year old in the replacement of a lot of valve electronics for transistor electronics in a large factory. Effectively, we designed plug-compatible modules, that just replaced the original systems.

    From what has been said, I believe that Hitachi are using this method and their battery modules, will behave like diesel engines to the train. I would even make them the same weight to not upset the handling of the train.

    There would probably be very little retraining of the drivers after a diesel module was swapped for a battery pack.

    Comment by AnonW | September 4, 2021 | Reply

    • Well I hope you’re right, it’s just that they weren’t doing it 10-15 years ago.
      I’m sure though that modularity will give less excuses and your point about recycling redundant equipment must be factored into the lifecycle cost projections.

      Comment by fammorris | September 5, 2021 | Reply

  3. I’ll agree with that!

    I also suspect that a train manufacturer would make sure that the battery design enabled repurposing of old batteries into another business. I think Renault, use old car bbatteries for houses, as it’s a less stressful application.

    Comment by AnonW | September 4, 2021 | Reply

  4. ah well, solid-state batteries are the next great thing, and vast sums of money are being spent on bringing them into mass production. I’m no expert on the science, but the consensus is that it’s a tough nut to crack. However, I’m old enough to remember an article in the New Scientist ca 1980 doubting that CDs could ever be mass produced, as the laser technology was so complex. Now lasers are used all over the place and nobody gives them a second thought. I suspect (and hope) SSBs may be the same.

    Comment by Peter Robins | September 5, 2021 | Reply

    • I can remember in the 1960s someone expressing astonishment that Harwell had built a one Farad capacitor. Skeleton and others have built much bigger ones, that are suitcase sized.

      Skeleton seem to have done well!

      Comment by AnonW | September 5, 2021 | Reply

    • CDs, aren’t you streaming?

      Comment by fammorris | September 5, 2021 | Reply

      • Not me! I haven’t listened to music, since my wife died.

        Comment by AnonW | September 5, 2021

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