First light: The Riding Sunbeams trial of solar-powered electric traction

Posted: November 10, 2019 by oldbrew in innovation, Travel
Tags: , ,

Credit: Railfuture

Well, 10% solar-powered – that’s the target. Of course solar has its variables, mainly weather conditions and hours of daylight. So is this ‘solution’ worth the bother and cost, or not? The era of batteries on train locomotives has also arrived – see ‘Adding a third dimension – battery power’ here.

How many times have we looked at clever innovation and wondered why on earth no one thought of doing it before?

Often the simplest of ideas seem to lead to the most elegant of engineering solutions, says RailEngineer.

The truth is, of course, that invention is only half of the story. Sometimes the right meeting of minds must happen before a bright idea can become a reality.

To the best of our knowledge, the direct supply of solar power to rail traction systems has never been done, anywhere in the world.

Now, thanks to a collaboration between Network Rail and a social enterprise scheme called Riding Sunbeams, the very first solar farm to directly supply power to trains has been switched on.

That’s right, not in a distant country with a hot climate and wall to wall blue skies, but right here in our cloudy UK, near Aldershot station to be precise. The new system went live on 23 August.

Riding Sunbeams is a joint venture between 10:10 Climate Action and Community Energy South. 10:10 is a registered charity on a mission to speed up action on climate change by inspiring more people to become involved, while Community Energy South was set up in 2013 as an umbrella organisation, enabling community organisations and local energy groups to grow as sustainable low carbon businesses.


Behind the Riding Sunbeams project is a pretty simple idea. It is that solar farms could be installed next to the train tracks – on embankments, train sheds, nearby fields and industrial buildings – and that these could power the railway directly to provide traction power for the trains.

In 2017, the 10:10 charity brought together experts from the Energy Futures Lab at Imperial College London, Community Energy South and electrical engineering specialists Turbo Power Systems, to find out whether the idea was feasible, and the answer was yes.

It was estimated that solar traction power could realistically provide around 10 per cent of the energy needed to power trains on the UK’s 750V DC electrified routes.

Community energy, where local people own the renewable energy and benefit from it, is at the heart of this work. Riding Sunbeams has a mission to see community and commuter-owned solar farms powering the railways for the mutual benefit of the railway routes, the communities that host them and, of course, the planet. In other words, to have third-party funding contributing to the national rail network.

This is no madcap scheme; the idea has huge potential for metros, trams and heavy rail in the UK and around the world.

Network Rail purchases an awful lot of electricity. The potential to obtain even 10 per cent of the DC third rail electrified network’s energy requirements from renewable sources, and at a cheaper rate, was worthy of consideration.

Stuart Kistruck is Network Rail’s director asset management for the Wessex route. In 2017, he had attended a presentation by Riding Sunbeams. “Making use of solar energy, produced on our own land, seemed like such an obvious thing to do,” he said.

Full article here.

  1. ivan says:

    Oh dear, another pie in the sky idea to get unreliable energy paid for by the public. For a start it would be much cheaper to get the reliable power from a HELE coal fired power station in the first place since one is going to be needed 90% of the time to keep the trains running.

    BTW, I seem to remember that 10:10 were the people that made films of teachers blowing up the heads of students that questioned the global warming myth. Seems that since that didn’t get enough traction they have had to find another loony idea to run with.

  2. MrGrimNasty says:

    Brighton is introducing battery buses, with diesel engines on board to charge the batteries. Up to 3 miles in electric mode – the world is saved!

    Meanwhile Brighton Council’s ‘Valley Gardens’ scheme is about to complete the deliberate policy of traffic obstruction (and hence maximization of pollution) by obstructing the main coastal route for all through traffic – removing ‘The Aquarium’ roundabout and replacing it with a junction, despite a mountain of objections.

    Greens – making the world dumber and dirtier and more expensive for you.

  3. Gamecock says:

    ROI doesn’t matter when it is someone else’s investment. Most projects will be approved if someone else is paying for it. The threshold is quite low.

    ‘The era of batteries on train locomotives has also arrived’

    My mother worked for Electro-Motive in the 1940s. Train locomotives were running from batteries then; they still do today. ‘Bi-mode’ as the article describes.

    Wrong link?

    The declaration ‘era of batteries on train locomotives has also arrived’ is bizarrely ignorant.

    So I looked at the linked article to see who said it. It’s not there. In fact, the opening paragraph in this tallbloke post isn’t there. I suspect someone put the wrong link in.

    [mod] search for ‘Adding a third dimension – battery power’ in the link

  4. oldbrew says:

    Peak solar is a few hours at best either side of the middle of the day. Peak passenger train times are around the start and end of the standard working day. No match.

    “By its nature, the supply is intermittent and we have a very peaky load. And of course, the periods of peak demand and peak generation don’t coincide.”

    Depending on the nature of the rail traffic, there can be long periods with no demand interspersed with periods of high demand. Leo continued: “A train under acceleration may draw up to 2,000 Amps. Lineside storage (batteries) could provide a solution, but the required technology for rail systems is not developed. We would be faced with perhaps a five-year development programme, which couldn’t pay for itself.

    “Even in the long term, the business case for using battery storage doesn’t look as good.”
    – – –
    Surely the battery needs to be on the train, not on the side of the line? Hybrid trains are now in use, and the UK will be using them soon if not already in service.

    The train battery can be used as a kind of range extender – opposite to EV cars which need a range extender – to travel on lines with no overhead or third rail electricity. Or for diesels to avoid noise and exhaust fumes when departing from stations, for example (plus other uses – see linked articles).

  5. Gamecock says:

    After further review, I see that I was mistaken. In the U.S. diesel-electric, the diesel engine drives alternators, which power the traction motors directly. The traction motors are not driven from batteries.

    There are batteries on the train, but they are for the diesel starter and other electrical functions, not the drive system.

  6. Curious George says:

    Is this noble enterprise fully paid for by charities?

  7. oldbrew says:

    CG – it may have something to do with this…

    The Rural Community Energy Fund

    The Rural Community Energy Fund (RCEF) is a £15 million programme, jointly
    funded by the Department for Environment, Food and Rural Affairs (Defra)
    and the Department for Business, Energy & Industrial Strategy (DBEIS). It
    supports rural communities in England to develop renewable energy projects
    which provide economic and social benefits to the community

    Click to access RS_BeforeDawn_Report_web.pdf

    In another report they say:
    we hope to invite commuters and railway workers to cooperate with lineside communities to crowdfund investment in the first wave of renewable traction projects made possible through this work

    Click to access RidingSunbeams_Report_final.pdf

    This report also says:
    Network Rail is the single biggest unregulated consumer of electricity in
    the UK, procuring around 3.2TWh of electricity centrally for the entire
    rail industry each year. This is equivalent to roughly 1% of the UK’s total
    electricity demand.

    Network Rail have explicitly targeted direct supply of renewable traction
    power as a priority for Control Period 6 (2019-2024) via a new formal
    Challenge Statement: “Using Large Scale Renewable Developments to
    Enable Decentralised Supply to the Rail Infrastructure.” This identifies
    “developing solutions to enable private-wire generation directly to the
    traction or non-traction infrastructure” as a specific research need,
    and recognises the important business opportunity for Network Rail in
    pursuing this agenda.

    This report is the first major contribution to meeting this challenge.
    Network Rail engineers have carried out a preliminary appraisal of options
    for using alternative energy sources on their traction systems. This
    identified solar PV plus storage, integrated at dc traction substations, as
    the option offering the greatest potential benefits to their networks.

  8. Curious George says:

    “develop renewable energy projects which provide economic and social benefits to the community.”
    A very nice oxymoron. Right now there is no such animal.

  9. oldbrew says:

    Job title: ‘solar traction farmer’ (see report) 🤔

  10. Dave Ward says:

    @ivan – “BTW, I seem to remember that 10:10 were the people that made films of teachers blowing up the heads of students that questioned the global warming myth”

    Yes, as soon as I saw them mentioned I checked:

    If that link doesn’t work, just search “No Pressure (film)”

  11. Graeme No.3 says:

    Many years ago (on a visit to the UK) I was stuck on a railway station out in the country in pitch darkness at 4 p.m. Trouble with a train. Fortunately a reliable diesel one turned up (about an hour later).
    How are these solar trains going to work on an overcast winter day at peak hour? Has anyone calculated how much electricity would need to be stored, and the cost of the necessary batteries? Or is Climate Change going to abolish winter?

    Another “charity” whose fantasy is being supported by bureaucrats wasting public money.

  12. ivan says:

    It appears that Jonathan Swift had this scam listed in Gulliver’s Travels when he mentioned the wasting time on projects such as the extraction of sunbeams from cucumbers. This project is about as useful.

  13. oldbrew says:

    The trains are already running on electricity. They’re just trying to add in some solar power to the existing supply.

  14. ivan says:

    They’re just trying to add in some solar power

    But at what extra cost to the travelling public and how much in subsidies do they expect to get?

  15. Gamecock says:

    Indeed, ivan. The idea is very old. Why do it now? What has changed?

  16. oldbrew says:

    AFAIK the subsidy era is over for UK solar.

    RS say:
    Our analysis indicates that a first wave of six to ten solar traction farms
    could be community owned and built with backing from secure, long
    term (27 year) power purchase agreements to supply Network Rail with
    electricity at a price per kWh that matches the price they pay today
    under their current supply contract. Profit margins for this community
    owned solar traction farm portfolio would be modest, but sufficient to
    underwrite crowdfunded investment, and to generate some surplus for
    community benefit funds.

    Click to access RidingSunbeams_Report_final.pdf

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