Solar cell is the only practically viable power source with no moving parts. Stop trying to attach it to moving things. Movements breaks things. Just put the panels by the rail, e.g. as vertical sound barriers in reasonable distance (to lower the pressure waves from train) from tracks. Or on a nearby field where it can be protected and inspected all at one place.
Or don’t put the panels near a railway at all. We have so much land and even empty rooftops that would be easier and safer to use first. Running panels along a railway means the electricity has to be carried all the way back to some point, meaning either giant cables to handle the current or specialized equipment and high voltage transmission lines. None of that was addressed by this pilot program that was 100 meters long.
You can do a pilot test of solar panels anywhere and call it a success, but the real test is scaling it up in an economically viable way compared to alternatives. None of that was tested.
Putting panels in a line is the worst arrangement. Just put them on roof tops or fields and keep it to places where they don’t have to be armored and reinforced.
I'll never understand why people latch onto these kinds of solar "solutions" in search of problems. Like that solar roadways fiasco a decade or so ago.
Just normal-ass solar is already safe proven and effective. Why do we need to remix it when there are still so many easy wins to be achieved?
Yeah, I can understand putting solar on things when it lets them become standalone off-the-grid setups but for something like railroad track it’s just not that much space and the costs are so much higher. Except on the tightest urban lines, just putting rows of normal panels next to the tracks should be significantly more space with much easier engineering.
It does seem kind of silly to put the panels between the rails, more prone to damage there from stuff falling off the trains, derailments, etc. and not angled for optimal sun exposure though I guess it's easy open space.
Before I read the article I was thinking the electricity from the panels would power the trains but doesn't sound like the output is enough.
They're getting 180 watts per meter, so it would take 50 km of panels to power one high speed train. And that's when the sun is shining. Double this at least if you want to store the energy and run trains in the evening.
And yet it did work, with positive results shown over a year, right? It seems that the reasons why this "could never work" like cracks, dust, and vibrations might have perfectly reasonable solutions. Solar panels have gotten so cheap that it might not be as important to install them in perfect conditions, and other factors like real estate, ease of maintenance, access to the grid come into play in interesting ways. I suppose long term results are yet to be seen, but it doesn't seem ridiculous to me.
You can put panels on anything and generate power for a couple years.
This system was only 18kW. That’s less than what we put on some residential houses. They didn’t address any of the hard parts like a transmission system capable of scaling up along a linear row of panels extending kilometers long.
> Solar panels have gotten so cheap that it might not be as important to install them in perfect conditions, and other factors like real estate, ease of maintenance, access to the grid come into play in interesting ways.
They had to use special panels for this, not the cheap ones you know. Any installation in an area like this requires reinforced and protected panels, which are more expensive than what you’re thinking.
You did identify some of the problems: Maintenance on this is terrible. They’re not going to shut down train routes to fix problems with the solar, so when something breaks it’s probably broken for years until a maintenance window can shut down transpiration.
Access to grid is terrible. You can’t re-use the train power lines, so I guess we’re running new transmission lines? A linear array is the worst possible configuration for a solar array because it maximizes the transmission distance and starts to require high voltage equipment to work.
Would you ever think it would be a good idea if someone suggested we go put solar panels out in the middle of nowhere between towns? Or would you agree it’s better to put them close to the towns on unused space like rooftops where they can feed directly into local loads? I think the visual of putting these on train tracks is misleading a lot of people into thinking we’re getting something for free when really this is an absurdly expensive way to place and connect solar panels.
That video is good - seeing the train-car dropping the panels into place makes it clear that you have some immediate labor savings on the initial deployment. Not sure if the post-installation labor was significant or could be automated away.
Still not sold on the idea. For something with a 20+ year life span, the initial deployment effort seems kind of irrelevant and should be better located somewhere that does not require ongoing activity. Train ballast requires replacement every N years which is going to require ripping up all of those panels.
> seeing the train-car dropping the panels into place makes it clear that you have some immediate labor savings on the initial deployment.
Dropping panels in place is not the hard part. Getting all of that electricity back to a connection point is one of the many problems created by this idea.
Putting panels in a multiple kilometer long end-to-end row is very inefficient compared to rectangular layouts that can be clustered around connection points.
What are the economics of this? Cost to install vs other available options? Durability will certainly be an issue I’m sure. Genuinely curious and not because I think it’s a bad idea. I want solar on all underutilized areas, I just prefer low hanging fruit from a cost perspective at the current time.
I imagine that the cost to install is fairly low since train tracks require regular monitoring and maintenance so it's fairly cheap to add the installation and maintenance on top of the existing schedule.
The manufacturer claims that durability should not be an issue. Time will tell.
Yes, worsened inspection is a non-trivial problem. Very high quality sleepers (I wouldn't expect any other kind in Switzerland) mitigate this, but copying such approach in other countries could spell trouble.
Seems likely that safe access for maintenance makes this unappealing economically. Likely easier to have wider rail right of way and then put a panel farm on the side.
With the added benefit of being able to mount the tracks at an angle, and the added disadvantage of occupying area near the tracks that is occasionally used for maintenance equipment.
And getting approval to widen the right of way, where it’s even physically possible, and issues around flora suppression.
Remains to be seen, considering how much snake oil there is in the solar market (but to be fair, this makes more sense than solar roads). A news article summary of a press release isn't proof of much.
I have tried entrepreneurial stuff twice before, in my 20s, though without much success. Having ideas good enough to get investors interested is a sign that perhaps I should have another go at it.
These are not ideas worth pursuing from an engineering standpoints. It doesn't make any sense compared to just doing the cheap and proven at scale thing of just placing them in normal fields.
But I will agree that the idea has proven marketing merit. This is a class of truly top tier snake oil. The solar roadways people continue to go unbelievably far on almost the same grift.
It makes more sense than the road, because at least the train isn’t driving directly on the thing. I wonder if the power could be delivered directly to the train. Although the only savings really would be transmission costs, not sure how big of a deal that is…
It's solar, of course the unit economics are going to pencil out positive in the majority of climates and energy markets. The real question is "why should we put them here instead of somewhere else."
I wonder if the benefits are legal/jurisdiction/political. The total amount of track they could install this on is huge, and it doesn't seem like something that will be disagreeable on the local level. It could just be the easiest place to put it to deal with property law and zoning etc.
Another political benefit is that it means work for a very large number of jurisdictions, as there are suitable tracks just about everywhere.
Initially, he planned to remove dust from the surface of the photovoltaic cells using a cylindrical brush mounted on the rear of a train. “However, we realised that each time a train passes, it creates an airflow that sweeps away all the dust,” he said.
That seems pretty optimistic in the long run. Even a high power leaf blower won't get all the dust off of a dirty surface, especially if any sort of hydraulic oil, bearing grease or other viscous fluid mists onto the surface.
One thing that has struck me with our own solar panels is that they have to be very dirty before I notice any significant degradation in efficiency. And when they do get completely covered in pollen or leaves, a brief rain is usually enough to clean them.
I'm in the south UK, live off grid, and have a bunch of solar panels, none of them are flat aside from the 640w of panels on my van, which generate almost nothing during the Winter.
Panels on the sides ot trains might be a better solution.
Putting solar panels in familiar places is always popular as an idea, but rarely better than putting them on the usual roofs or as rectangular arrays on the ground.
> the railway was fitted with 48 specially-designed solar panels with a combined power of 18 kWp.
18 kW is less than what gets installed on a lot of houses. It took 100 meters to do this. The farther the panels get from the interconnect, the higher the losses along the line.
It’s easy to set up 18kW of panels in one spot. Covering an entire railway with panels would require a different transmission setup to get the power back to somewhere useful.
I really wish we could just forget all of these ideas to put solar panels in places that are highly trafficked and serving double duty. Just put them in unused space that isn’t used for anything else: Rooftops, empty fields, or over parking garages. I often get downvoted for saying this because a lot of people like these ideas of putting solar panels in space that they see, like sidewalks or roads or railways, but we have so much unused space that isn’t near foot traffic, road traffic, or railways that is so much cheaper and easier to use for solar. These projects usually turn into political grifts to get government funding because the ideas are not economically viable alternatives.
> Thankfully, Switzerland has lots of meters of railway.
The linear meters of railway are nothing compared to the square meters of rooftops. Putting panels in a long row is the maximally worst arrangement you can come up with.
> There's caternary on 99% of Swiss rail, every few dozen meters, that already transmits power.
I guarantee this wasn’t oversized to accommodate power transmission duties, too.
It’s also high voltage line. The solar setup would need additional and expensive high voltage equipment to interface with the line and to work within the design parameters of a line that was designed to deliver to the train, not carry extra power.
You could put the panels anywhere else and connect them normally to the grid like every other installation.
> You understand that wire doesn’t have infinite capacity, right?
Why would it need that? Your original complaint was "18 kW is less than what gets installed on a lot of houses". Which is it? Too much to handle or too little?
Did we really fill up all the area on top of roofs, parkings lots, industrial areas, etc., and we're running out, and we have to put solar cells on railroads?
> Did we really fill up all the area on top of roofs, parkings lots, industrial areas, etc., and we're running out, and we have to put solar cells on railroads?
I guess it is easier to control the deployment since they own the railroads.
Would you be better off just building an additional nuclear power plant.
This trial tied the panels to the grid, but they want to connect it to railway substations or directly in to the trains power system for the traction motors.
Making the power only available for trains.
And never at night, as is typical with solar panels.
Solar cell is the only practically viable power source with no moving parts. Stop trying to attach it to moving things. Movements breaks things. Just put the panels by the rail, e.g. as vertical sound barriers in reasonable distance (to lower the pressure waves from train) from tracks. Or on a nearby field where it can be protected and inspected all at one place.
Or don’t put the panels near a railway at all. We have so much land and even empty rooftops that would be easier and safer to use first. Running panels along a railway means the electricity has to be carried all the way back to some point, meaning either giant cables to handle the current or specialized equipment and high voltage transmission lines. None of that was addressed by this pilot program that was 100 meters long.
You can do a pilot test of solar panels anywhere and call it a success, but the real test is scaling it up in an economically viable way compared to alternatives. None of that was tested.
Putting panels in a line is the worst arrangement. Just put them on roof tops or fields and keep it to places where they don’t have to be armored and reinforced.
I'll never understand why people latch onto these kinds of solar "solutions" in search of problems. Like that solar roadways fiasco a decade or so ago.
Just normal-ass solar is already safe proven and effective. Why do we need to remix it when there are still so many easy wins to be achieved?
Yeah, I can understand putting solar on things when it lets them become standalone off-the-grid setups but for something like railroad track it’s just not that much space and the costs are so much higher. Except on the tightest urban lines, just putting rows of normal panels next to the tracks should be significantly more space with much easier engineering.
friends of friends simply need all that sweet government grant money
It does seem kind of silly to put the panels between the rails, more prone to damage there from stuff falling off the trains, derailments, etc. and not angled for optimal sun exposure though I guess it's easy open space.
Before I read the article I was thinking the electricity from the panels would power the trains but doesn't sound like the output is enough.
They're getting 180 watts per meter, so it would take 50 km of panels to power one high speed train. And that's when the sun is shining. Double this at least if you want to store the energy and run trains in the evening.
This will never work, and it's ridiculous: https://youtu.be/7vItnxhWRqw
And yet it did work, with positive results shown over a year, right? It seems that the reasons why this "could never work" like cracks, dust, and vibrations might have perfectly reasonable solutions. Solar panels have gotten so cheap that it might not be as important to install them in perfect conditions, and other factors like real estate, ease of maintenance, access to the grid come into play in interesting ways. I suppose long term results are yet to be seen, but it doesn't seem ridiculous to me.
> And yet it did work,
You can put panels on anything and generate power for a couple years.
This system was only 18kW. That’s less than what we put on some residential houses. They didn’t address any of the hard parts like a transmission system capable of scaling up along a linear row of panels extending kilometers long.
> Solar panels have gotten so cheap that it might not be as important to install them in perfect conditions, and other factors like real estate, ease of maintenance, access to the grid come into play in interesting ways.
They had to use special panels for this, not the cheap ones you know. Any installation in an area like this requires reinforced and protected panels, which are more expensive than what you’re thinking.
You did identify some of the problems: Maintenance on this is terrible. They’re not going to shut down train routes to fix problems with the solar, so when something breaks it’s probably broken for years until a maintenance window can shut down transpiration.
Access to grid is terrible. You can’t re-use the train power lines, so I guess we’re running new transmission lines? A linear array is the worst possible configuration for a solar array because it maximizes the transmission distance and starts to require high voltage equipment to work.
Would you ever think it would be a good idea if someone suggested we go put solar panels out in the middle of nowhere between towns? Or would you agree it’s better to put them close to the towns on unused space like rooftops where they can feed directly into local loads? I think the visual of putting these on train tracks is misleading a lot of people into thinking we’re getting something for free when really this is an absurdly expensive way to place and connect solar panels.
It could make sense along an electrified rail line, if the power lines used to supply the trains can be leveraged for distribution?
But, putting panels between the rails seems foolhardy to me too.
there may be solutions to it but there are just already existing places to put solar panels that don't even require coming up with solutions.
Better article with video: https://www.swissinfo.ch/eng/emissions-reduction/solar-energ...
That video is good - seeing the train-car dropping the panels into place makes it clear that you have some immediate labor savings on the initial deployment. Not sure if the post-installation labor was significant or could be automated away.
Still not sold on the idea. For something with a 20+ year life span, the initial deployment effort seems kind of irrelevant and should be better located somewhere that does not require ongoing activity. Train ballast requires replacement every N years which is going to require ripping up all of those panels.
> seeing the train-car dropping the panels into place makes it clear that you have some immediate labor savings on the initial deployment.
Dropping panels in place is not the hard part. Getting all of that electricity back to a connection point is one of the many problems created by this idea.
Putting panels in a multiple kilometer long end-to-end row is very inefficient compared to rectangular layouts that can be clustered around connection points.
What are the economics of this? Cost to install vs other available options? Durability will certainly be an issue I’m sure. Genuinely curious and not because I think it’s a bad idea. I want solar on all underutilized areas, I just prefer low hanging fruit from a cost perspective at the current time.
I imagine that the cost to install is fairly low since train tracks require regular monitoring and maintenance so it's fairly cheap to add the installation and maintenance on top of the existing schedule.
The manufacturer claims that durability should not be an issue. Time will tell.
Placing a cover over the area between the tracks makes it much more difficult to inspect the ties (sleepers) and ballast.
Yes, worsened inspection is a non-trivial problem. Very high quality sleepers (I wouldn't expect any other kind in Switzerland) mitigate this, but copying such approach in other countries could spell trouble.
Seems likely that safe access for maintenance makes this unappealing economically. Likely easier to have wider rail right of way and then put a panel farm on the side.
With the added benefit of being able to mount the tracks at an angle, and the added disadvantage of occupying area near the tracks that is occasionally used for maintenance equipment.
And getting approval to widen the right of way, where it’s even physically possible, and issues around flora suppression.
Always nice when something that I suggest in a random comment only to get a dismissive reply, turns out to be an idea worth persuing all along.
> idea worth persuing
Remains to be seen, considering how much snake oil there is in the solar market (but to be fair, this makes more sense than solar roads). A news article summary of a press release isn't proof of much.
Being right about things you have no control over is a bit like being right about your favorite flavor of jelly.
Of course.
I have tried entrepreneurial stuff twice before, in my 20s, though without much success. Having ideas good enough to get investors interested is a sign that perhaps I should have another go at it.
Can you be wrong about your favorite flavor of jelly?
These are not ideas worth pursuing from an engineering standpoints. It doesn't make any sense compared to just doing the cheap and proven at scale thing of just placing them in normal fields.
But I will agree that the idea has proven marketing merit. This is a class of truly top tier snake oil. The solar roadways people continue to go unbelievably far on almost the same grift.
It makes more sense than the road, because at least the train isn’t driving directly on the thing. I wonder if the power could be delivered directly to the train. Although the only savings really would be transmission costs, not sure how big of a deal that is…
> at least the train isn’t driving directly on the thing
It’s just kicking up dust and dripping lubricant onto it.
Maybe this makes sense. I’m deeply sceptical. Especially when you could just be putting vertical panels to the sides.
It's solar, of course the unit economics are going to pencil out positive in the majority of climates and energy markets. The real question is "why should we put them here instead of somewhere else."
I wonder if the benefits are legal/jurisdiction/political. The total amount of track they could install this on is huge, and it doesn't seem like something that will be disagreeable on the local level. It could just be the easiest place to put it to deal with property law and zoning etc.
Another political benefit is that it means work for a very large number of jurisdictions, as there are suitable tracks just about everywhere.
> It's solar, of course the unit economics are going to pencil out positive in the majority of climates and energy markets
This is far from an of course. There were idiots trying to do solar roads a few years ago. The math didn't pencil out.
That seems pretty optimistic in the long run. Even a high power leaf blower won't get all the dust off of a dirty surface, especially if any sort of hydraulic oil, bearing grease or other viscous fluid mists onto the surface.
One thing that has struck me with our own solar panels is that they have to be very dirty before I notice any significant degradation in efficiency. And when they do get completely covered in pollen or leaves, a brief rain is usually enough to clean them.
At least trains no longer drop literal shit between rails...
I'm in the south UK, live off grid, and have a bunch of solar panels, none of them are flat aside from the 640w of panels on my van, which generate almost nothing during the Winter.
Panels on the sides ot trains might be a better solution.
Putting solar panels in familiar places is always popular as an idea, but rarely better than putting them on the usual roofs or as rectangular arrays on the ground.
> the railway was fitted with 48 specially-designed solar panels with a combined power of 18 kWp.
18 kW is less than what gets installed on a lot of houses. It took 100 meters to do this. The farther the panels get from the interconnect, the higher the losses along the line.
It’s easy to set up 18kW of panels in one spot. Covering an entire railway with panels would require a different transmission setup to get the power back to somewhere useful.
I really wish we could just forget all of these ideas to put solar panels in places that are highly trafficked and serving double duty. Just put them in unused space that isn’t used for anything else: Rooftops, empty fields, or over parking garages. I often get downvoted for saying this because a lot of people like these ideas of putting solar panels in space that they see, like sidewalks or roads or railways, but we have so much unused space that isn’t near foot traffic, road traffic, or railways that is so much cheaper and easier to use for solar. These projects usually turn into political grifts to get government funding because the ideas are not economically viable alternatives.
> It took 100 meters to do this.
Thankfully, Switzerland has lots of meters of railway.
> Covering an entire railway with panels would require a different transmission setup to get the power back to somewhere useful.
There's caternary on 99% of Swiss rail, every few dozen meters, that already transmits power.
> Thankfully, Switzerland has lots of meters of railway.
The linear meters of railway are nothing compared to the square meters of rooftops. Putting panels in a long row is the maximally worst arrangement you can come up with.
> There's caternary on 99% of Swiss rail, every few dozen meters, that already transmits power.
I guarantee this wasn’t oversized to accommodate power transmission duties, too.
It’s also high voltage line. The solar setup would need additional and expensive high voltage equipment to interface with the line and to work within the design parameters of a line that was designed to deliver to the train, not carry extra power.
You could put the panels anywhere else and connect them normally to the grid like every other installation.
> I guarantee this wasn’t oversized to accommodate power transmission duties, too.
Its sole purpose is power transmission, to the trains.
You understand that wire doesn’t have infinite capacity, right? You can’t just point to a wire and say “problem solved”.
I can’t even tell if you’re honest or just trolling at this point in the conversation.
> You understand that wire doesn’t have infinite capacity, right?
Why would it need that? Your original complaint was "18 kW is less than what gets installed on a lot of houses". Which is it? Too much to handle or too little?
> There's caternary on 99% of Swiss rail, every few dozen meters, that already transmits power.
Switzerland runs on 15 kV catenary voltage. Transformers suitable for that kind of voltage cost a lot of money.
Trains AND solar power. Awesome.
Solar sidewalks, solar roads, now solar rail?
WHY?! Dave from eevblog did the math and it's bad
Did we really fill up all the area on top of roofs, parkings lots, industrial areas, etc., and we're running out, and we have to put solar cells on railroads?
I think these kinds of ideas capture easily impressionable, elected representatives whose technical knowledge is non existent.
> Did we really fill up all the area on top of roofs, parkings lots, industrial areas, etc., and we're running out, and we have to put solar cells on railroads?
I guess it is easier to control the deployment since they own the railroads.
Today we sail
On the Solar Rail
For there's much we just don't know
So farewell with a kiss
Then it's fast for the mist
Till we're sleeping in the cold below
Cold: the metal boxes going
Hard: the tracks on which we roam
Panels when the dark's not coming
Feel the weight of what we tow
Would you be better off just building an additional nuclear power plant.
This trial tied the panels to the grid, but they want to connect it to railway substations or directly in to the trains power system for the traction motors.
Making the power only available for trains.
And never at night, as is typical with solar panels.
An ETH study says no.
https://lenews.ch/2026/07/04/new-nuclear-plants-a-difficult-...