Is V2T (vehicle-to-train) the next energy storage technology?

Train - Extra Zebra (CC BY 2.0)

The EV of the future will be just one component of an integrated transportation/energy ecosystem that includes private cars, public transport, renewable energy sources and stationary storage.

Could trains and cars, both powered by electricity, share not only passengers, but also energy? The idea may not be as outlandish as it seems.

Hybrid and electric vehicles use regenerative braking to recover energy that would otherwise be lost to friction. Electric trains similarly lose large amounts of energy during their frequent braking, but there’s no practical way to capture and store this energy. Trains do not carry large batteries, and they are typically connected to an electrical grid that can’t handle quick bursts of energy.

A new research project led by the University of Sheffield is exploring ways to harness this untapped source of energy. The recently launched TransEnergy project will investigate how battery storage solutions could be used to help power Britain’s railways.

“We’re going to see further electrification of the rail network, and obviously we need better provision of electricity in order to allow the network to run seamlessly,” project leader Dr. Martin Foster told businessGreen. “The idea of this research project is to look at whether we can use battery energy storage systems to provide some form of energy buffering for the network.”

The concept is that energy generated during braking at a station would be stored nearby in stationary batteries, then used to accelerate the train when it starts up again. In one scenario, stationary storage would be augmented by the batteries of EVs parked at the station.

Dr. Martin points out that within the next 10 to 15 years, train station parking lots could be filled with EVs. “Why not use the batteries that are on board those electric vehicles?” he asks. “Often at large train stations and tram stops, you have park-and-ride facilities where people are commuting to work. They leave their car at the car park, and they’re not returning for several hours. So you’re almost guaranteed a certain usage profile for the system.”

The TransEnergy project plans to install a demonstration energy storage system, and a feasibility study is currently underway with the London Underground. The researchers are also talking to Merseyrail, which serves the Liverpool metro area.


Source: businessGreen
Image: Extra Zebra (CC BY 2.0)

  • Ozzie Perch

    I proposed this years ago and it was rejected because the result is still a bit negative…and we still don’t have the intermountain guideway either…

  • brian_gilbert

    Driverless cars are likely to be adopted as the problems of human-drivers crashing into the driverlessvehicles have not been solved.
    The driverless cars/taxis will maybe only 1/30th of the current number lof cars and in use most of the time so will not be parked idle in station car parks. Trains can have supercapacitor batteries to conserve the reactive braking energy. Many train services could be replaced by driverless coaches with the railway turned into a road. In many cases this would give a far better service with less changing needed by the passengers and a far more frequent service. Less chance of accidents too as no need for ‘points’. Pity it needs government cooperation to go completely driverless as the technology is there.

    • Vincent Wolf

      No it’s not. Look at what happened with just an ‘auto’ mode for Tesla recently–their sensors failed to pickup a white truck that pulled across it’s path. This is just an example. Try driving in a hard rain or snowstorm and see how well those sensors work and decisions made are valid compared to what a person can do. Not gonna happen in my lifetime period.

      • brian_gilbert

        I propose a completely driverless system. The white truck was not driverless and not under comtrol of the central control system. If it had been then the two vehicles would not have been allowed to be in the same place.
        GPS and 5G have advanced considerably in the last year or two and they will work in bad weather. The vehicles only have to stick to a lane whereas at present they are expected to range the width of the carriageway.The comtrol system Would probably slow vehicles down in bad weather or stop them. It could also reroute them.
        Personal Rapid Transit systems have been operating on a small scale since 1975.
        I umderstamd your doubts and do not deny that it needs staedily growing trials before we put a lot of trust in them but hard to believe they could not reduce the one millian lives a year lost in road accidents.

  • jstack6

    I’d like to see V2G with cars and trucks take off first. Then other variations like this would be even better to keep us ON TRACK.


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  • Barry L Alexander

    But mass transit systems can do this currently, the issue is costs. And as with all of these proposals they cost a lot, take a long time to do, and need a massive infrastructure investment in manufacturing, mining, etc.

    • brian_gilbert

      The same could be achieved with completely driverless vehicle syatem. Becuase only a small fraction of the current number of vehicles is needed and no change to the roads the cost can be recovered in less than a year. In fact by making currently budgetted road widening unnecessary it even saves money.

      • Barry Alexander

        Sure anything is possible as long as you control the assumptions. No a small fraction is not acceptable it might serve a need but not a desire. For example we have two cars and two drivers, my wife refuses to give up her personal car even if I give her preference in using my car. So your assumption is not reality. Even if it was how fast do you think you could manufacture the required vehicles, how fast can say battery production be expanded? Just living in an alternative reality. Not that I would not like it but it is not happening. how about just having transporters and replicators?

        • brian_gilbert

          The small fraction is enough to more than meet present need for vehicles at any one time. In Singapore for example less than 10% of the cars are in use at peak periods. IN London at peak hours I can still see a car on the driveways of most houses in my road. Unless tour wife is a driving enthusiast I suspect she would be happy for less cost to be taken in a limousine of her choice to her usual destinations and not have to walk from the corner of the carpark to the front door of her favourite shop in bad weather. But in a democracy tou should have a vote on it. Soomer or later some countries will adopt it and if it is a success some others will follow.
          With less than a tenth of the vehicles required the vehicles could be produced in less than a year with existing resources. Centrally maintained they would last indefinitely being replaced only when the need changed. I would expect it to start in one area of a country and expand and adjust as it covers the rest.
          I do not know whether production of the batteries could match that of the rest of the vehicle so you have me there. The batteries might not be lithium-ion as they are only optimum for the present low usage over the vehicle life Used up to 24 hours a day other designs last longer.
          It might help to go for a ride in the driverless vehicles operating since 1975 at 4 locations:- Morgantown, West Virginia, Masdar, Abu Dhabi, Heathrow Airport, UK, or Suncheon, South Korea. They all operate on short routes on dedicated guideways and take 4 or more people. I think there would be a higher demand for exclusive use of the vehicle for one person or their family. Busses and coaches also available.
          Transporters and replicators are a bit dodgy as they have a bug which causes multiple copies. Your wife might be pleased but not yourself. Don’t tell me you were reading science fiction in the 40s as well!

          • Barry Alexander

            Perhaps you are correct, but no neither she nor I are happy to wait or be in some say uber car. We and many others are used to having a car at our personal bidding. Now I speak only for those in the US, not some other country that is not a reasonable comparison. In addition I have family about 100 miles away, no limo for that, I go to various places that are say 30 miles away also no limo there. Here in rural US we want and need individual cars, not to mention trucks to pull our boats, carry our stuff etc. Now perhaps in a big city with decent mass transit I would use it. I see you live in London so you don’t understand the US not in big cities. And I agree on voting and letting experiments happen. Thanks for the conversation.

          • brian_gilbert

            Thankyou too. Over and out.

  • Vincent Wolf

    The wastefullness of our system of gas/diesel vehicles in this world has been extreme. The potential for energy savings is huge if the world will just commit and throw off the yoke of big oil.

  • nordlyst

    For new infrastructure there’s a much easier way to at least reduce the waste: locate stops at elevation compared to the rest of the track. For metro lines this has the additional benefit of allowing trains to drive closer to each other because of increased passive safety. And it saves a little time because the train accelerates better out from the station going downhill!

    • brian_gilbert

      The latest electric cars include ‘reactive braking’ this saves 80% of the braking energy in a battery that can accept fast charging/discharging rates such as a supercapacitor. It is also used on some trains already. The charge in the battery can then be used to assist acceleration.