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.
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.
You aware, what always runs right next to a railway right? I mean the capacity might be already saturated for the driving current, but cables next to the railway won't be a new thing.
That's just inefficient use of labour. I wish government used grants (or loans really) for solar farms instead. Batteries maybe, but even then it would be likely more efficient to install them on a substation level than every home.
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?
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.
More like engineered and worked around to be safe (unless you are in Australia lol). 400v around people is unforgiving. Batteries catch fire occasionally too - a lot of places you are not allowed to install indoors.
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.
How often is a train derailed? And even then everything has to be replaced anyway...
Same goes for "stuff falling off", you can easily replace the panel(s)
Literally, they are not being attached to a moving thing and are being put by the rail lol. Just in between the tracks.
Like you say, PV cells don’t have moving parts and don’t need much maintenance. So mass produced cells you can slap anywhere are really not a bad idea.
Did you forget about batteries and fuel cells?
RTFA
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.
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.
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.
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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
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...
Regenerative breaking on trains is a thing.
3000kw is about 1/2 power for the most common Swiss electric engines.
And peak demand determines grid size.
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.
The manufacturer claims that durability should not be an issue. Time will tell.
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?
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.
And getting approval to widen the right of way, where it’s even physically possible, and issues around flora suppression.
There are interesting aspects to the project like the idea of the train being able to clean the panels as it goes over them, or having a pre-made track for easier install and maintenance, but these seem quite minor when you consider the number of obstacles (increased mechanical strain, possibility of damage, non-optimal angle, hard to schedule maintenance around train times, maintenance is more dangerous, all the panels are placed linearly so you need extra cable routing, large efficiency losses when you're trying to transport low voltage electricity from remote areas).
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.
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.
https://www.swissinfo.ch/eng/emissions-reduction/solar-energ...Panels on the sides ot trains might be a better solution.
> 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.
> 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.
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.
Switzerland runs on 15 kV catenary voltage. Transformers suitable for that kind of voltage cost a lot of money.
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.
(to me it seems especially nuts because there's plenty of space to the side of most railways!)
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.
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?
But ignore the bit of "why not both"
For the amount of money spent here, we could've build quite a few kilowatts of power capacity on more traditional surfaces, like if the project had to be rail related, on eg. roofs of rail platforms.
I guess it is easier to control the deployment since they own the railroads.
But no, instead we have this grifting rail solar nonsense.
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
Hard: the tracks on which we roam
Panels when the dark's not coming
Feel the weight of what we tow
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.
cries
There are also a lot of vertical sound proofing barriers that could be equipped with panels.
That's just inefficient use of land.
On the battery point I agree.
I just did a cross country drive a few days ago. We are not constrained on land.
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.
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.
Sure. I'm unconvinced a railroad is the best place we need to be putting panels for anything other than PR value.
Its sole purpose is power transmission, to the trains.
I can’t even tell if you’re honest or just trolling at this point in the conversation.
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?
If there's a single downside I'm not sure what it is.
* Midnight sun notwithstanding.
> in one year, the project has produced around 16,000 kWh.
160 kWh per meter.
Urban Metro / Trams: 2 to 10 kWh/km
Commuter Trains (EMUs): 4 to 12 kWh/km
Regional / Intercity Trains: 6 to 20 kWh/km
High-Speed Trains: 15 to 60 kWh/km
Freight Locomotives: 10 to 50+ kWh/kmI 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. 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.
But you cant just drop the p. The p means you won't even get that.
This part seems correct tho:
> ...so it would take 50 km of panels to power one high speed train.
160 MWh/km * 50 km = 8 GWh = 8 000 000 kWh
High-Speed train after acceleration uses about 30 kWh/km
8GWh / 30kWh = 270000km
A typical high speed train in Europe drives between 300 000 and 450 000 km/year
The 50 km solar wouldn't be enough.
A passenger train using 6 kWh/km could drive 1 350 000 km using 50 km of solar.(27000 km/km)
There is about 10 000 km of high speed rail in the EU and about 200 000 km of rail in total. All combined trains travel some 4.1 billion km per year.
4 100 000 000 km / 27 000 km = 151 851 km
It fits but very slowly.
We should order the 72 888 480 panels. If they cost 50 euro each it would only cost 3.6 billion.
Took them 3 years to install 48 so 72 million would take 4.5 million years.
Maybe the Chinese can help.
Again, I think fossil fuels need to go and solar is our best bet, but no sense in hand waving the entire argument. They need a lot of land area.
Lets not forget that it's not just the land the power plant sits on that is used by fossil fuels.
VAST areas are mined and drilled out
Planning permission was put in to add a solar farm. Got "objections" because it's "farm land".
It's not viable to grow anything on...
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.
But, putting panels between the rails seems foolhardy to me too.
- ... often has its land use sited far away, in Texas and the Dakotas, or even offshore. Solar would realistically have to go everywhere; even assuming perfect transmission(!), you don't want to bunch it up in one region so it's not a single point of failure.
- ... employs lots of people / requires constant high-paying labor. Solar is built once then mostly just sits there. Which is good! But explains why residents might be fine with the former, but not the latter.
- ... is more easily hidden away. See LA's hidden oil rigs.
- ... already kinda exists. Which is a lame argument, yeah, but obviously people are going to be fine with the pumpjack or oil field that's been there their entire lives, vs. new solar farms coming in and taking over what was forest or farmland.
Again, I'm on solar's side here, obviously it's a better land use. But we can't just handwave away the entire land use issue, it's that kind of stance that makes people grow hostile to it.
Or are you talking about a different Poland?
People don't take up that much space and there is a strong tendency for populations to collapse into concentrated cities. In general, across the entire human species. All cultures and countries behave this way.
I think you've got plenty of free land.
Pretty much all of the land in Poland is used - either for agriculture, forests or human settlements.
So like maybe 99%? Are you say it should be strictly 100% and none of it for solar?
You only need 1% of land for solar to sustain entire population.