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.
Conveniently, there's already an electric cable sized to transport a few MW nearby. This might reduce the cost of installation, also there'll be no land acquisition/impact study issues.
However, I agree that putting solar panels in between or near rails will increase the cost of maintenance: the technicians will need to travel longer times to the work site, and now they also need to be certified to work near railroads.
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?
> Like that solar roadways fiasco a decade or so ago.
Should have many of the same drawbacks, with 2 big differences:
1. Trains not driving directly on the panels' surface (which makes solar roadways a bad idea in any case). And
2. Trains on their own track, so the 'road surface' conditions of the panels (rain, snow etc) don't matter safety-wise.
That said: imho there's still so many spaces better suited to put solar panels, that between train tracks is among the last places I'd go for. Especially if it requires custom-design panels.
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.
Exactly. For example, I think the lifted solar panels that have been popping up over parking lots are a perfect win-win. Cars get shade, power gets generated, it's out of the way of most day-to-day threats, and if they have to do repairs, it's just blocking off part of a parking lot instead of a major thoroughfare.
If there's a single downside I'm not sure what it is.
People hate the idea of solar in currently-unused space. Even if that space is bare desert. So you can get a big PR boost if you propose "solar, but on a thing" (roadways, water, and now trains).
Which is just odd to me because why are we holding one of the cleanest means of generating electricity to a higher standard than like, coal and oil? Why does solar have to have 0 footprint when everything else gets as much of a footprint as it wants? (I know the answer is profit)
Protecting the panel from the freak large hail storm from inside the track also seems a lot harder than having it in a field with angle adjusting mounts/software.
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.
It's obviously not 180 kWp/m. If it was I could put 1 meter of panels on my roof and power my house and 200 of my neighbors.
I didn't try to calculate the amount of energy it produces in a year, just the length of panels required to power a high speed train when the sun is shining. 18,000 watts / 100 meters is 180 watts per meter. At 180 watts per meter, 50 km gives you 9 MW, which is about what a high speed train consumes at cruise.
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.
A first version is always going to be low in scale and problems will of course be found. The question isn't 'are there problems', of course there are, the question is 'are the benefits here worth more than the problems'. If you already have the land, a maintenance operation, a user of energy, etc etc then integrating solar into that system has a lot of strong benefits that can make the problems manageable. Start looking for the upside here and you may actually find the cost benefit equation balances out, especially if this scales out.
> A first version is always going to be low in scale
They don’t have a first version of the hard part: The electrical transmission.
Maybe this isn’t obvious to people who haven’t worked on solar power systems, but you can put a couple panels anywhere and generate electricity for a couple years. It doesn’t prove that it’s viable to run thousands of kilometers of panels.
It’s like baking a tray of muffins in your kitchen and saying you proved that you can run an industrial scale muffin factory. They are different problem sets.
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.
I've been nerd-sniped into google fueled napkin math.
18kw/100 m = 180kw/km
The most powerful Swiss electric locomotive [1] maxes out at 7900kw. That's 44km of track.
The most common Swiss electric (4/4) typicaly maxes at 6100kw requiring up to 34km of track.
Switzeraland has about 5000km of track and 180 is about 200, so a million kilowatts if all the track has solar panels.
Assuming 3000kw per locomotive and 100% efficiency [2], that's 300 electrical locomotives running simultaneously. The Swiss fleet is about four times that.
You don't need peak power all the time. The point of trains is that they're extremely efficient; most of the time they're essentially coasting, they only need a lot of power when accelerating or ascending.
If you want hard numbers, SBB used 1685GWh for passenger trains in 2025 [0].
The bigger problem with this idea is solar in Switzerland. It's fantastic during the summer but close to nonexistent during the winter [1]. Trains need to run year-round, so you'd need to overbuild solar monstrously to power SBB during the winter, or you'd need to solve seasonal electricity storage, which isn't easy. Pumped hydro is great but Switzerland has already built about as many artificial alpine lakes as the population is likely to tolerate.
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.
I'm not an expert but I think the SBB is already pretty good at handling this. I think they already run measuring wagons (Oberbaumesswagen) with grond penetrating reader and ultrasonic measurement and use flow sensors to monitor drainage.
I would expect that the solar panels impact the efficiency at least somewhat but apparently not enough to cause real and enough issues for the SBB or perhaps they see ways to improve this in the future.
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.
This might be exactly what you are asking for: low cost and low hanging fruit.
On paper, this should be pretty cheap. Normally, you need some mounting infrastructure to put the panels on, land preparation, etc. In this case, the train track provides the supporting infrastructure. You can bring in the panels via train wagons. Installation should be pretty quick and straightforward. And for cleaning, you could just do that from a rail wagon as well. Not having to truck in anything seems like it should be a big bonus here.
Durability might actually be fine. Solar panels are pretty reliable. And it's not like the train is in direct contact with the panels. The vibrations might be a challenge but presumably that would have shown up in the trials. It's something you could engineer solutions for. And so what if a small amount of panels fail?
Another issue with solar deployment is that there needs to be power cables that can consume the electricity.
But a train company practically always has running trains when the sun is shining. So they wouldn’t need to worry about disabling and losing money on the panels.
The real challenge is economically connecting the panels to a rail substation.
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.
So requires more transmission infrastructure. The difference is that we already have that built out over decades, and now we need a different network in a much shorter timescale.
No one should pretend that the energy transition is free. The final system we will arrive at can be ver
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.
This is a great example of the solar ecosystem finding new niches. Tracks are likely good because there is already constant maintenance and inspections on them as well as ready hookup to the grid or, as the article mentions, directly providing power for trains. The point here isn't that this is 'the most efficient way to use solar' it is that it works and provides benefit. It is like agrovoltaics. The solar production is lower than a dedicated solar installation, but the dual use of the land and potential secondary benefits make it worth while. It looks like this could even get to the point where solar could actually power the trains completely assuming this expanded a little beyond just the track surface which could be interesting for the design of trains.
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.
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?
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.
I don't know why people fall for this stuff. It doesn't make any kind of sense. You put the panels in a rectangular array in any convenient place. That's what wires are for.
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.
They don't need to because it is just a PoC and I don't think it hs been said anywhere that soloar panel between rain tracks would be the unique source of energy.
There are also a lot of vertical sound proofing barriers that could be equipped with panels.
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.
Apparently it is so slow and expensive to build nuclear power so no commercial entities are interested without extreme government subsidies and guarantees.
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.
Conveniently, there's already an electric cable sized to transport a few MW nearby. This might reduce the cost of installation, also there'll be no land acquisition/impact study issues.
However, I agree that putting solar panels in between or near rails will increase the cost of maintenance: the technicians will need to travel longer times to the work site, and now they also need to be certified to work near railroads.
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?
> Like that solar roadways fiasco a decade or so ago.
Should have many of the same drawbacks, with 2 big differences:
1. Trains not driving directly on the panels' surface (which makes solar roadways a bad idea in any case). And
2. Trains on their own track, so the 'road surface' conditions of the panels (rain, snow etc) don't matter safety-wise.
That said: imho there's still so many spaces better suited to put solar panels, that between train tracks is among the last places I'd go for. Especially if it requires custom-design panels.
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.
Exactly. For example, I think the lifted solar panels that have been popping up over parking lots are a perfect win-win. Cars get shade, power gets generated, it's out of the way of most day-to-day threats, and if they have to do repairs, it's just blocking off part of a parking lot instead of a major thoroughfare.
If there's a single downside I'm not sure what it is.
People hate the idea of solar in currently-unused space. Even if that space is bare desert. So you can get a big PR boost if you propose "solar, but on a thing" (roadways, water, and now trains).
Which is just odd to me because why are we holding one of the cleanest means of generating electricity to a higher standard than like, coal and oil? Why does solar have to have 0 footprint when everything else gets as much of a footprint as it wants? (I know the answer is profit)
That is not the answer (plenty of profit in solar), it's probably that society is literally older and so people don't like change as much.
friends of friends simply need all that sweet government grant money
Protecting the panel from the freak large hail storm from inside the track also seems a lot harder than having it in a field with angle adjusting mounts/software.
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 is incorrect, you mean 180 kWp/m.
> in one year, the project has produced around 16,000 kWh.
160 kWh per meter.
It's obviously not 180 kWp/m. If it was I could put 1 meter of panels on my roof and power my house and 200 of my neighbors.
I didn't try to calculate the amount of energy it produces in a year, just the length of panels required to power a high speed train when the sun is shining. 18,000 watts / 100 meters is 180 watts per meter. At 180 watts per meter, 50 km gives you 9 MW, which is about what a high speed train consumes at cruise.
> This is incorrect, you mean 180 kWp/m.
This is incorrect. 18000 Wp/100m = 180 Wp/m or 180 kWp/km. So parent is correct, and you can either add or drop a "k".
That is peak power, obtainable in summer months & muuch less in winter.
Over the whole year: 16000 kWh/100m = 160 kWh/m = 160 MWh (160,000 kWh) per km.
Did you read the article?
This will never work, and it's ridiculous: https://youtu.be/7vItnxhWRqw
If you don't think about it, it doesn't seem like a bad idea. If you do, you realized how incredibly complex the whole thing is
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.
A first version is always going to be low in scale and problems will of course be found. The question isn't 'are there problems', of course there are, the question is 'are the benefits here worth more than the problems'. If you already have the land, a maintenance operation, a user of energy, etc etc then integrating solar into that system has a lot of strong benefits that can make the problems manageable. Start looking for the upside here and you may actually find the cost benefit equation balances out, especially if this scales out.
> A first version is always going to be low in scale
They don’t have a first version of the hard part: The electrical transmission.
Maybe this isn’t obvious to people who haven’t worked on solar power systems, but you can put a couple panels anywhere and generate electricity for a couple years. It doesn’t prove that it’s viable to run thousands of kilometers of panels.
It’s like baking a tray of muffins in your kitchen and saying you proved that you can run an industrial scale muffin factory. They are different problem sets.
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.
I've been nerd-sniped into google fueled napkin math.
The most powerful Swiss electric locomotive [1] maxes out at 7900kw. That's 44km of track.The most common Swiss electric (4/4) typicaly maxes at 6100kw requiring up to 34km of track.
Switzeraland has about 5000km of track and 180 is about 200, so a million kilowatts if all the track has solar panels.
Assuming 3000kw per locomotive and 100% efficiency [2], that's 300 electrical locomotives running simultaneously. The Swiss fleet is about four times that.
---
Of course I am no expert.
[1] https://en.wikipedia.org/wiki/List_of_stock_used_by_Swiss_Fe...
[2] and ignoring the 10 per year efficiency loss of the panels mentioned in the article
You don't need peak power all the time. The point of trains is that they're extremely efficient; most of the time they're essentially coasting, they only need a lot of power when accelerating or ascending.
If you want hard numbers, SBB used 1685GWh for passenger trains in 2025 [0].
The bigger problem with this idea is solar in Switzerland. It's fantastic during the summer but close to nonexistent during the winter [1]. Trains need to run year-round, so you'd need to overbuild solar monstrously to power SBB during the winter, or you'd need to solve seasonal electricity storage, which isn't easy. Pumped hydro is great but Switzerland has already built about as many artificial alpine lakes as the population is likely to tolerate.
[0]: https://reporting.sbb.ch/en/sustainability?=&years=5,6,7,1&s...
[1]: https://energiedashboard.admin.ch/strom/produktion
You don't need peak power all the time
3000kw is about 1/2 power for the most common Swiss electric engines.
And peak demand determines grid size.
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.
I'm not an expert but I think the SBB is already pretty good at handling this. I think they already run measuring wagons (Oberbaumesswagen) with grond penetrating reader and ultrasonic measurement and use flow sensors to monitor drainage.
I would expect that the solar panels impact the efficiency at least somewhat but apparently not enough to cause real and enough issues for the SBB or perhaps they see ways to improve this in the future.
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.
This might be exactly what you are asking for: low cost and low hanging fruit.
On paper, this should be pretty cheap. Normally, you need some mounting infrastructure to put the panels on, land preparation, etc. In this case, the train track provides the supporting infrastructure. You can bring in the panels via train wagons. Installation should be pretty quick and straightforward. And for cleaning, you could just do that from a rail wagon as well. Not having to truck in anything seems like it should be a big bonus here.
Durability might actually be fine. Solar panels are pretty reliable. And it's not like the train is in direct contact with the panels. The vibrations might be a challenge but presumably that would have shown up in the trials. It's something you could engineer solutions for. And so what if a small amount of panels fail?
Another issue with solar deployment is that there needs to be power cables that can consume the electricity.
But a train company practically always has running trains when the sun is shining. So they wouldn’t need to worry about disabling and losing money on the panels.
The real challenge is economically connecting the panels to a rail substation.
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.
[flagged]
> Everywhere grid scale solar goes, expensive new transmission lines follow.
How is this different than any other power generation install?
Solar (and wind, I guess) is way more spread out? Other power generation happens at a point on a map by comparison.
So requires more transmission infrastructure. The difference is that we already have that built out over decades, and now we need a different network in a much shorter timescale.
No one should pretend that the energy transition is free. The final system we will arrive at can be ver
This has some more photos of the solar panels and the laying of them https://www.swissinfo.ch/eng/emissions-reduction/solar-energ...
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.
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This is a great example of the solar ecosystem finding new niches. Tracks are likely good because there is already constant maintenance and inspections on them as well as ready hookup to the grid or, as the article mentions, directly providing power for trains. The point here isn't that this is 'the most efficient way to use solar' it is that it works and provides benefit. It is like agrovoltaics. The solar production is lower than a dedicated solar installation, but the dual use of the land and potential secondary benefits make it worth while. It looks like this could even get to the point where solar could actually power the trains completely assuming this expanded a little beyond just the track surface which could be interesting for the design of trains.
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.
1. That was 20 years ago. I wonder how it would pencil out now.
2. Yeah it was kind of dumb to put the panels into a high wear environment like a road.
3. What matters more is which projects pencil out the best. There are too many to choose from that have a positive ROI.
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...
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.
To be fair, swiss train tickets cost a lot of money too.
Trains AND solar power. Awesome.
Bad website. No photo, only a video, and that wants to start with an ad.
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.
WTF is the downvote for?
You didn't promote nuclear power.
But promoting it seems like a way to get bombed back to the stone age by the Muricans.
I don't know why people fall for this stuff. It doesn't make any kind of sense. You put the panels in a rectangular array in any convenient place. That's what wires are for.
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.
And all the train depots and train stations are already covered in solar panels, I presume.
They don't need to because it is just a PoC and I don't think it hs been said anywhere that soloar panel between rain tracks would be the unique source of energy.
There are also a lot of vertical sound proofing barriers that could be equipped with panels.
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-...
Apparently it is so slow and expensive to build nuclear power so no commercial entities are interested without extreme government subsidies and guarantees.
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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