Photovoltaics are still running after a year under Swiss trains

It is just over a year since a pilot project to install photovoltaics on a railway line kicked off. According to the CEO of Sun-Ways, the company behind the scheme, the challenge was not so much technical as regulatory. The project, a 100-meter photovoltaic installation on a railway line open to traffic, was inaugurated on April …

[Martin an gof]

300 an hour?

So... if this magical machine of theirs can lay 300 panels per hour (complete with connections??) can it also remove 300 panels per hour so that maintenance can be carried out, for example re-laying ballast? Maybe these would be better suited to concrete bed track, but there's not a vast amount of that around Europe from what I gather. (parts of) HS2 in the UK I think, assuming we can ignore the Lizzy Line!

I wonder if there's any mileage in using flexible solar films instead. Less efficient but potential just to roll it out (and up again) like carpet.

M.

[AndrueC]

Re: 300 an hour?

Maybe these would be better suited to concrete bed track, but there's not a vast amount of that around Europe from what I gather. (parts of) HS2 in the UK I think, assuming we can ignore the Lizzy Line!

I'd be interested in seeing figures for that. In the UK at least concrete sleepers are the preferred choice. Wooden sleepers tend to only be used in specific locations eg; under turnouts which benefit from the extra cushioning. I'd have thought that was broadly the case across Europe and all modern railways.

ChatGPT (yeah I know..) seemed to confirm this and pointed to some sources for example (Network Rail - UK).

If you search for 'concrete sleepers' you'll find tables showing sleeper renewals. In 2011 335km of concrete sleepers were renewed against 7km of wooden and 103km of steel. Now unless concrete and steel sleepers are hugely more prone to wear and tear than wood (which they aren't - they last longer) that suggests that wood is in the minority.

[Cornishinretirement]

Re: 300 an hour?

I think the OP is referring to concrete slab track, which does not need ballast. Concrete sleepers, which are everywhere, still need ballast and the maintenance that goes with it.

[Anonymous Coward]

Re: 300 an hour?

Indeed. Ballast needs mechanical attention about once a year on a line with frequent, fast or heavy trains, and the machines that do this are not gentle, and this applies to all ballast around and between the sleepers. On a lightly trafficked branch it would only need redoing 3-5 years.

[Fruit and Nutcase]

Track maintenance and track laying machines...

Plasser & Theurer...

in particular, tamping to set the ballast...

https://www.plassertheurer.com/en/machine/tamping/overview

[Cliffwilliams44]

Re: 300 an hour?

Correct, my employer used to operate these machines here is the US (we had to buy them from Europe, no one over here even makes them) and they are not gentle. The panels would HAVE to be removed and that is going to cause unacceptable delays! Our machines were tracked by the hour, and any delays were a very big deal, as traffic cannot be run over that line to the RRs needed to know when they would be done and you had better hit that target.

[IvyKing]

Re: 300 an hour?

My first thought on seeing the article was "dragging equipment" which could tear up tens of panels per minute. Interfering with ballast tamping is another issue, rail lines with a lot of freight traffic may need tamping several times a year.

[Roland6]

Re: 300 an hour?

>” from what I gather. (parts of) HS2 in the UK”

It will be whole length of HS2 - the full concrete trackbed is big part of the cost increase.

Given HS2 Phase 1 is 140 miles of which 34.5 miles are tunnels, that is -potentially 211 miles of panels. The only problem I can see is with the scallys who will want to compete with each other throwing bricks etc. trying to break the panels.

[John Robson]

Oh but just you wait

There will be people coming along saying that doing this will stop trains running at night or some such nonsense.

There will have to be a robust mechanism for isolation for maintenance and in the, rare but inevitable, case of an 'incident'. Neither of which are significant blockers.

[Anonymous Coward]

Re: Oh but just you wait

It's a bloody stupid idea. The area between the rails is tiny compared to available building roof space, what could be ground-mounted alongside the railway etc. Then there's the issues like the fact that the railway is dirty and other than on the most lightly trafficked branches the panels the panels will need regular cleaning, they'll be at risk of damage from flung ballast, rail grinder detritus, need annual removal to facilitate ballast maintenance, have to be proof to the very high pressure sprays used for rail head cleaning during autumn.

Just because it is technically possible as a short demonstration doesn't make it a sensible idea. There's far better places to put PV.

[Fred Daggy]

Re: Oh but just you wait

This whole AC post is a good excercise in negging. The points raised are non-issues.

"The area between the rails is tiny compared to available building roof space" What? Yes, for a single building. But there are thousands of linear kilometers of tracks multiplied by 1 meter wide or so. In Switzerland alone. Most buildings go up to, about, what 100m2 or there abouts?

*the railway is dirty and other than on the most lightly trafficked branches* The railways usually use .... electricity. At least here they do. And no they are not dirty. Other countries may use diesel. Has the UK moved out of the coal era yet?

Yes, the tracks could be subject to being covered in snow. But it's been like that since railways were invented. And the have a solution : A massive freaking snow blower. Also works for a few leaves.

[Anonymous Coward]

Re: Oh but just you wait

There's plenty of dirt sources in any moving vehicle besides the energy source and trains are no exception. At the most fundamental level, why do you think tracks and wheels need to be replaced periodically?

To answer your question about British railways, while about 40% of the tracks are electrified, over 70% of track miles covered each year are done so under electric power.

Regarding the snow blower, I would like to see what data there is on how these panels hold up to chunks of ice being thrown around or ground against then.

[Anonymous Coward]

Re: Oh but just you wait

"Regarding the snow blower, I would like to see what data there is on how these panels hold up to chunks of ice being thrown around or ground against then."

It's almost as if they've just had a year's trial...

And that trial will have been exposed to all the leaves, snow, and wheel wear that would affect a set of panels in that location.

Much (but not all) of the damage to wheels/rails is plastic deformation, not wear in the "material loss" sense.

[Philo T Farnsworth]

Re: Oh but just you wait

I find it a clever idea and certainly worth trying. Even if it fails, we probably learn something. We certainly spend money on worse endeavors.

The two issues of consequence I see are the potential for vandalism (humans are just an awful species that way) and for theft (see previous parenthetical).

I'm not sure how well such a scheme would work here in the US where most rail traffic is freight rather than passenger (no idea what the ratios are in Europe and the UK) and, of course, our engines run on good old American diesel.

I rode a "heavy rail" commuter train to work for a number of years and if the tracks along the platform were any indication, the spaces between the rails were pretty grody with tar, oil drippings, and who knows what else, so keeping panels clean would be a bit of a challenge here.

[HereIAmJH]

Re: Oh but just you wait

the spaces between the rails were pretty grody with tar, oil drippings, and who knows what else

Some of that might be decades of waste oil sprayed around the tracks to stop plants from growing. The thing I wondered about, do US passenger trains still dump their toilets on the track? That would make cleaning the panels a nasty job.

[MachDiamond]

Re: Oh but just you wait

"The thing I wondered about, do US passenger trains still dump their toilets on the track?"

No, they don't. On longer stops of cross-country trains, they service the black water tanks and refill the fresh water. I'd not be surprised if gray water is released as they go with maybe some retention while in stations, etc.

[Philo T Farnsworth]

Re: Oh but just you wait

I can only speak about the commuter rail train I rode daily and a couple of Amtrak trips up the California coast but from my observation the toilets work more or less like airline toilets, i.e., they're smelly and kind of gross, but otherwise retain their contents for more hygienic disposal.

There is no prohibition from using the toilet while in the station.

[Fred Daggy]

Re: Oh but just you wait

I suspect theft and to a lesser extent vandalism might be an initial problem, but one that self-solves. Mainly by sudden applications of several hundred tons of fast moving train. (See also "Darwin Awards"). Noted that live cables don't necessarily stop copper theft, which should also be self-solving problem. "Self-Selecting group" might have nine lives.

I hope that any train drivers and other personnel are not affected by the self-selecting group of idiots.

[Cliffwilliams44]

Re: Oh but just you wait

You are clueless!

Have you ever seen a ballast machine in operation? It digs out the old ballast from the sides and between the ties and replaces it with new, the panels would have to be removed, quite labor intensive. When these machines are operating on a line that line cannot be used. So, the time to completion is very important. Rail Roads are not going to accept those delays!

[Anonymous Coward]

Re: Oh but just you wait

> This whole AC post is a good excercise in negging. The points raised are non-issues.

Reading the comments section here has always been an amusing exercise. You would think all the world's Experts in Everything congregate here. If only the commentardat ever got out on the real world all the problems would be fixed forever.

[Rjan]

Re: Oh but just you wait

I imagine maintenance is actually considered one of the advantages rather than the disadvantages.

The additional dismantling during underlying track maintenance is not a significant concern provided the power generated by the panels is profitable enough overall to outweigh the labour cost, and the railway is ideally suited to carrying specialised heavy machinery necessary to bulk store, lay, re-lay, and clean such panels (not just in the four-foot, but potentially at any adjacent distance that can be reached from rail-mounted machinery).

[vtcodger]

Re: Oh but just you wait

Add to all that, the test section was probably selected because, among many other things, it has a relatively unobstructed horizon. One would suspect that Switzerland, being notoriously not very flat, large parts of the railbeds of the railroad network will be in the shadow of mountains, railway cut walls, buildings and/or trees much or all of the day. Same would likely be true I think of many (most?) other European countries.

[Dinanziame]

Re: Oh but just you wait

One would suspect that Switzerland, being notoriously not very flat, large parts of the railbeds of the railroad network will be in the shadow of mountains, railway cut walls, buildings and/or trees much or all of the day

Switzerland does have a lot of mountains, but don't overestimate the shadows they cast — mountains are much less steep than most people think. I remember an American asking me how Switzerland can have a football team, since obviously with all those mountains it must be very difficult to have enough flat land for a football field...

[JohnMurray]

Have to wait in UK...

Until 'direct dump' of toilet contents onto the line is 100% phased out!

[abend0c4]

Re: Have to wait in UK...

Even then there will be "leaves on the line" issues. Not to mention stray cattle with their associated weight and leavings. I'm assuming the Swiss have ensured they're sufficiently robust to survive snow clearing.

[MachDiamond]

Re: Have to wait in UK...

"Even then there will be "leaves on the line" issues. Not to mention stray cattle"

Leaves and other plant material could be an issue, but cows on a high speed track would be rather problematic.

[Fruit and Nutcase]

Cows on the line

tucows have been on the information super highway for a very long time

https://www.tucows.com/

[Steve Goodey]

Re: Have to wait in UK...

Are we still doing that?

[Phil O'Sophical]

Re: Have to wait in UK...

No, AFAIK it's banned since 2020 or so, except for heritage lines. They might still do it but in my experience they just keep the in-carriage toilets locked. No-one wants to do track maintenance if those trains are allowed.

[blot-on-the-landscape]

Re: Have to wait in UK...

if they installed those on some UK rail lines, the solar panels would disappear before the first train timetable. The copper cables would probably go with them too!

[david 12]

Re: Have to wait in UK...

It would all be aluminum cables.

[david 12]

Re: Have to wait in UK...

https://jzdcable.com/can-photovoltaic-cable-use-aluminum-conductors-a-complete-guide/

"When to Consider Aluminum Alloy PV Cable?

Aluminum alloy PV cable is a viable, cost-effective solution for specific, large-scale scenarios:

(*)Large Utility-Scale Solar Farms:​ Where the cost savings on long string runs from the array to the combiner boxes can be substantial.

(*)Projects with Long DC String Runs:​ Where voltage drop can be managed by careful conductor sizing.

[Korev]

Re: Have to wait in UK...

There are still some railway lines here in Switzerland with that "system"

Reichenbach Falls icon -->

[Tempest 3K]

Re: Have to wait in UK...

Been banned for a few years now on Network Rail tracks - painfully aware of this as involved with a group operating preserved stock and retrofitting this with Controlled Emission Toilets which has been a costly undertaking with more than a few headaches for our engineering team!

[Ramis101]

19MWh? are you sure?

As someone with a good number of PV panels on my roof (32), even given that these are getting on for 2m in length, but i would think slightly narrower than standard roof panels to fit between the tracks, 19MWhs looks like a decimal point in the wrong place to me, 1.9 sounds realistic. 19 is more than i generate in 3years!!

That said, i'm not dissing the idea. It sounds like a great utilization of wasted space coupled with easy access to power infrastructure. Feed the solar directly into the overheads if possible?

[Anonymous Coward]

Re: 19MWh? are you sure?

Pretty sure you don't have 100 METERS worth of panels on your house roof, which is extremely likely that you don't have 100 square meters of roof available. Your reading comprehension is abysmal.

[Ramis101]

Re: 19MWh? are you sure?

100meters, 48 panels = around 2m per panel. roof panels come in at around 1.7m x1.1 ish

The gauge of railway track is around 1.4m

the picture shows a large non-solar join in the length and also what looks like a good 10cm gap either side.

So i would say, these panels are comparable with mine, just a little longer probably.

Therefore, the difference in power generated (especially as the article states their Sup Optimal Angle placement - i did read it and understood it too), should be comparable.

So 16 extra panels..... and a difference of around 3x over my yearly generation. These must be some SUPER EFFICIENT new panels.... But thanks AC for jumping down my throat on that.

[Irongut]

Re: 19MWh? are you sure?

> The gauge of railway track is around 1.4m

Not in Switzerland where they have 1,000 mm (3ft 3+3⁄8") gauge railways.

[abend0c4]

Re: 19MWh? are you sure?

FWIW, the Travers-Buttes line appears to be standard gauge.

[seven of five]

Re: 19MWh? are you sure?

While there are narrow gauge tracks in Switzerand, most rail is 1435mm

[Ramis101]

Re: 19MWh? are you sure?

I must admit, i only looked up UK gauge.

You learn something new every day.

Cheers.

[MachDiamond]

Re: 19MWh? are you sure?

"Not in Switzerland where they have 1,000 mm (3ft 3+3⁄8") gauge railways."

There's going to be deductions for tie plates and some margin.

[DrewPH]

Re: 19MWh? are you sure?

Even in Switzerland standard gauge is in the majority. How else do you think all the famous historical express trains got from Gemany and France to Italy?

[Fruit and Nutcase]

Goldenpass Express

Dual Gauge automatic adjustable bogies. They are also height adustable to allow for different platform heights...

https://www.youtube.com/watch?v=jJLRo4ao33k

https://en.wikipedia.org/wiki/GoldenPass_Express

A similar system is used in Spain, albeit without the height adjustment

[lglethal]

Re: 19MWh? are you sure?

Just for a comparison we have 23 standard sized panels on our roof here in southern Germany, at an absolutely not optimal inclination (we are north-south facing, so most panels only get optimal light for half the day), and we generate 8-9MWh per year.

So I can absolutely believe 19MWh with 100 panels.

[H in The Hague]

Re: 19MWh? are you sure?

Here in NL our 6 panels generate around 2000 kWh = 2 MWh per year. These are modern panels and installed in a favourable location. Our installation is actually quite modest compared to what other folk have.

Problem is: on sunny days there is now a glut of electricity. That means that net metering is coming to an end and the effective feed-in tariff is laughably low. So now looking at a home battery.

[lglethal]

Re: 19MWh? are you sure?

I can really recommend getting the battery. We have a 7kWh battery and for about 6 months of the year we basically dont download anything from the grid. Except for charging our Electric Car. Unfortunately, the battery cant disgorge energy faster enough even on our lowest charging setting.

Still it's a massive saving. Last year we exported twice what we imported. But unfortunately, the imported energy costs 3 times what we get paid for what we produce. So we're not quite cost zero, but it's still a massive reduction over what we used to pay...

[MachDiamond]

Re: 19MWh? are you sure?

"Problem is: on sunny days there is now a glut of electricity. That means that net metering is coming to an end and the effective feed-in tariff is laughably low. So now looking at a home battery."

It's a problem that's driving people back to water heater tanks as a way to use excess energy. I was just looking today on Aliexpress for something else and some multi-source water heaters came up. The price wasn't bad, but the shipping made them untenable. I didn't look very hard for the best overall price.

Batteries are coming down in price if you don't buy a name brand. Once I've flooged off a load of stuff I've picked up at estate sales, there a local seller that has 6kWh batteries at a good price. I'll have to fit a BMS, but those aren't too dear. I'm hoping I can afford something like a Chevy Bolt (used) later this year if the prices come down and I'll funnel as many electrons into that when I have a few spares.

Another good thing to do is look for things that can be shifted to daylight hours such as a dishwasher, clothes washer, etc. What's lacking right now is whole house energy control. It's rather hot where I am right now. If I had a entire roof full of solar panels, any excess capacity I'd be happy to stuff in the AC by lowering the setting. That would mean everything inside would cool down and less energy would be needed when the sun went down and the temp setting went back to something more reasonable. Invert for summer.

[lglethal]

Re: 19MWh? are you sure?

Just as a little tip, since we installed solar panels on our roof, we've noticed a genuine drop in temperatures in the house in Summer, especially in the Attic room directly under the roof (which also so happens to be our bedroom). Easily 5°C cooler there in summer, just due to the panels. And surprisingly it's also significantly warmer in winter. I guess it provides another nice insulating layer.

So even in winter when the panels are covered in snow, it's helping our house keep just that little bit warmer. One of the side benefits that does not get mentioned very often (probably because it cant really be converted into a monetary or energy value!).

[Roland6]

Re: 19MWh? are you sure?

I noted this benefit, given the panels are typically only 20~25 percent efficient, with a full roof covering of panels, that’s going to significantly reduce the amount of energy hitting the house roof.Additonally, with the panels raised off the roof I expect there is also a natural chimmy effect that will also reduce heat passing through the panels and hitting the roof.

[John Robson]

Re: 19MWh? are you sure?

I have 6 panels and generate a little over 2MWh/year.

So 48 panels would be ~8 times that, which is ~17MWh/year.

My panels are likely quite a bit older than those installed in this trial.

I am substantially further north than Switzerland, but I also have panels at a slightly better angle, albeit compromised by a little shading in the morning (from a neighbouring house) and in the depths of winter (from a tree about 4 gardens across as well as a neighbouring garage).

19MWh seems within the likely margin.

[notyetanotherid]

Re: 19MWh? are you sure?

10 15yo panels facing ESE in Midlands of England generate ~1.6 MWh per year for me.

[notyetanotherid]

Re: 19MWh? are you sure?

... using the online calculator, mentioned below, the average insolation for my installation's location is 2.3 kWh/m2: 1.6 MWh * 2.8/2.3 is, give or take, 1.9. Multiply by 10 for 100 panels and, there it is, 19MWh per year.

[Ian Johnston]

Re: 19MWh? are you sure?

According to an online calculator, average daily insolation for Bern is 2.79 kWh / m2. For a double track, 1.435m gauge railway that's 8 kWh/m or 800kWh for 100m. Annually, 146 MWh, so 19 MWh generated is a plausible 13%

[Roland6]

Re: 19MWh? are you sure?

Just click on the article link “generated”, it takes you to a dashboard page that gives power production data. They estimate 16MWh Pa.

[Ramis101]

19MWh? are you sure?

As someone with a good number of PV panels on my roof (32), even given that these are getting on for 2m in length, but i would think slightly narrower than standard roof panels to fit between the tracks, 19MWhs looks like a decimal point in the wrong place to me, 1.9 sounds realistic. 19 is more than i generate in 3years!!

[Chloe Cresswell]

Re: 19MWh? are you sure?

32 panels over 3 years and less then 19MWh?

I have 17 panels (JAM60S05-300/PR, so 7 year old tech at best) and generate an average of 5MWh per year.

[Ramis101]

Re: 19MWh? are you sure?

You cant fit 32 all on one side, so i have 16 per side due to the house being the wrong way round.

It equates to 8kW of panels. and yes, i get around 5 to 6 MWh/year too. My panels are 15yrs old now.

[Chloe Cresswell]

Re: 19MWh? are you sure?

I only have 5.1kW of panels, and my inverter max output is 3.86kW, and I'm still hitting 5MWh a year.

If I had 48 panels like the story, with the inverters to match the output of the panels, it would output roughly 14MWh a year.

Is that 5MWh a year extra after 6 years of solar improvements really that far out of belief?

[Martin an gof]

And removable.

My first question was, can they remove it too, for track maintenance, for example re-ballasting. Apparently they can. The website linked in the article says "modular and reversible, the system can be easily installed and removed, in whole or in part".

M.

[Anonymous Coward]

Re: And removable.

But still about as sensible as installing PV in the middle of a motorway. I really can't think of any logical reason to put PV in a hazardous location where you'll need a line closure for any maintenance or repair.

[Rattus]

Re: And removable.

maintenance is relatively easy:

o As already pointed out, maintenance trains exist.

o Panels are always in the same position relative to a maintenance vehicle (at least when considering 'precision' for any civil engineering project).

o Cleaning & inspection could be a simple matter of running a cleaning train (or a specific cleaning 'car' appended to a relatively slow moving service)

o Track inspection is already done on high speed engineering trains in the UK (see "flying banana" )

o Adding (semi-)Automated panel lift and lower to ballast trains shouldn't add time to existing re-ballast operations

o It would require additional resources (crew and specialist rail-cars)

As long as the cap-ex / op-ex comes in less than the cost of power generated everyone is a winner

And yes you would expect vandalism, but you would factor that in (and add some defence for it) - but this is no different from a solar farm or adding solar to existing railway infrastructure

And yes you need to factor in possible theft of cables for the copper - again see above, this is no different from a solar farm or existing railway infrastructure (indeed on a busy line possibly less likely given that you don't get much time to nick things before being splatted by an oncoming train that wouldn't notice a squishy meet-bag getting in the way until its next cleaning cycle....

Oh and finally - the railways already exist, so these linear solar farms wouldn't need to replace fields in an actual farm :-)

[MachDiamond]

Re: And removable.

Rattus

Current inspection/maintenance machinery doesn't take into account these panels so those would have to be refitted/replaced. Lifting the panels for re-ballasting would require a way to replace the panels aft of the re-ballasting.

[Richard 12]

Re: And removable.

Indeed, however given that they're installed by train-mounted automation in the first place, lifting and reinstalling isn't much of a stretch.

It would increase the cost of reballasting, but nearly all of the increase would be the fixed cost of rhe equipment, so just needs there to be enough PV laid to cover that.

[Rattus]

Re: And removable.

"Current inspection/maintenance machinery doesn't take into account these panels"

so yes maintenance trains already exist.as I said

so the additional cost would be to add waggons to the aforementioned maintenance train that would deal with the solar PV thus re-enabling the previous maintenance function.

Its not as if you need to re-invent (or buy entirely new) maintenance trains, you just need to add the new functionality of lift and replacing the PV.

and again as I previously stated - additional manpower and the cost of the PV maintenance 'waggons/cars' to be added to the train should be more offset buying the power from the grid (and be part of the overall cost of the system)

TIME on the other hand could be an issue- to all jobs we need to:

- Add in the time required to perform the INITIAL section of PV lift (must happen before other 'physical maintenance of the way' can happen)

- Add in the time required to perform the LAST section of PV re-lay (must happen after the last section of 'physical maintenance of the way' has finished and before the way can be re-instated into service)

All other lift and lay of PV sections can happen in front and behind the section of way being maintained at no additional delay to maintenance (providing that neither lift of lay functions take longer than the physical maintenance step)

[cyberdemon]

Re: And removable.

> All other lift and lay of PV sections can happen in front and behind the section of way being maintained at no additional delay to maintenance (providing that neither lift of lay functions take longer than the physical maintenance step)

...

Wallace & Gromit would like a word!

[MachDiamond]

Re: And removable.

"the system can be easily installed and removed, in whole or in part".

Not having to faff with R/R at all is even better. There's too much chance of things getting damaged when they are taken apart and reinstalled. A couple of stripped fasteners turns into loads more hours of labor.

[Phil Kingston]

Re: And removable.

They'd be removed by ne'er do wells in their first week in the UK

[MachDiamond]

Re: And removable.

"They'd be removed by ne'er do wells in their first week in the UK"

Word might get around they didn't have much value. Due to the size, it would be easy to spot where they came from. Most panels these days are much wider. I expect that there'd also be more more damage if they weren't nicked straight away after install. Somebody harvesting the leads would be more like it.

[Anonymous Coward]

The real challenge is regulation

Maybe not in Switzerland, but in some places the real challenges for this nice idea might end up being more along the line of vandals, thieves, and sabotage :-/

[ortunk]

Re: The real challenge is regulation

Yeah in my country keeping thieves off the rail tracks would offset all the savings

[phuzz]

Re: The real challenge is regulation

In the UK 22 people were killed trespassing on railways in 2024-2025, so possibly that would offset some of the thievery?

[The Organ Grinder's Monkey]

Re: The real challenge is regulation

A good proportion of those will have been by choice, sadly.

My best mate's landlord during his apprenticeship in Coventry was a gang leader on the permanent way, & was completely inured to finding stray body parts on the line as part of his daily endeavours. He was firmly of the opinion that Britain's missing persons lists could be greatly shortened if those random limbs could be identified. This was in the mid 80s, so maybe they are now DNA tested, but he was doubtful that there was much follow up at the time.

[Filippo]

Don't get me wrong. The more clean power generation we install, the better. Keep it up.

But I don't get why some projects are so focused on finding specifically the toughest places to install photovoltaic panels. Remember the company that wanted to build roads out of them? That was nuts from day 1.

I mean, have we run out of good old boring roofs and parking covers?

[AndrueC]

A few possible advantages:

• No need for planning permission.
• Easy access to power connections. On overhead lines it might be easier to find somewhere to plug the panels in. In built-up areas this can be a problem.
• No need to worry about mounting point strength. Not all roofs can take the weight of panels. Railway sleepers can and might even benefit from the extra weight.
• It's probably an easier thing to automate. You just need a machine that can trundle along the rails dropping the panels and fixing them in place. It might be possible to lay hundreds of square metres a day.
• Logistics might be easier. I mean you're basically laying things along a freight line. That has to be easier than getting vans and lorries into and around built-up areas.

[fnusnu]

One major disadvantage:

They are at the wrong angle for maximum efficiency.

[Chloe Cresswell]

If you have the space, does the lower efficiency really matter when you can just lay kilometres of them?

[Charlie Clark]

Yes, it does. Panels are around 25% efficient with optimal placement both of the panels and the sun, you've then got the transmission losses associated with low voltage DC lines – how often do you switch up to high voltage AC? The economics for deploying degrade fairly quickly when you don't have this, especially when you're to sell the power. While the Chinese have driven down the unit cost of panels, this is partly due subsidies and the real costs of making the silicon cells along with the silver and copper you need to connect them will not go away and you'll need lots of optimisers to handle the problems of variable sunlight.

This is why, for photovoltaic production, you really can't beat south-facing sites in spaces with low economic value for predictable yields. I'm sure some wonk could come up with the equivalent area for a convenient mountainside to really illustrate the difference over time.

We're also increasingly hitting problems of excess production at midday in the summer with no long-term storage and no cheap short-term storage.

[Tron]

It would be more expensive, but...

If you make the individual cells track the sun through the day, it may increase efficiency. There may be some way of employing organic, heliotropic material to dynamically adjust or reshape the lens/mount.

[Anonymous Coward]

Re: It would be more expensive, but...

How would a Ron Moody's eye nanotech solution help on a flat panel mounted horizontally? No more light will be captured by the panel.

[Not Yb]

Re: It would be more expensive, but...

I'll just remind you that the space between rails is flat, and there's not much space for anything but a thin panel. Even if it could be done in such a small space, this would also significantly increase the cost of a panel.

To really get good efficiency from tracking and angling the panels, they'd need to tilt significantly enough to have to flatten back down if a train approached during morning or evening.

[cyberdemon]

Re: It would be more expensive, but...

The fact that they are flat is not a big problem, the panels themselves are dirt cheap, you just need 25% more of them for the same power as angled panels.

It's still a daft idea though. For all the reasons others have mentioned above, plus i suspect the cost of closing the line for the amount of time it takes to install the panels would oughtweigh any money made from the electricity. Safety issues around vibration and damage, and what happens when the panels shake loose, get dislodged by the air draft from moving trains, and potential damage to trains or points as they do so..

Put them on the sidings by all means.. But not on the track itself

[vtcodger]

Re: It would be more expensive, but...

If you make the individual cells track the sun through the day, it may increase efficiency. There may be some way of employing organic, heliotropic material to dynamically adjust or reshape the lens/mount.

Ask yourself, how would Elon Musk solve that problem? Easy. We'll breed these giant sunflowers and train bats to mount small solar cells on the flowers. But, how will we get the electricity out of the cells? Not a problem. We'll use AI, or Blockchain or maybe quantum mechanics.

[Anonymous Coward]

Re: We'll use AI, or Blockchain or maybe quantum mechanics.

Vos is dis "or"?

[MachDiamond]

Re: It would be more expensive, but...

"If you make the individual cells track the sun through the day, it may increase efficiency."

Panels on a tracking mount gain about a 30% increase in production, IIRC. I'm not sure what the difference is between full 3D tracking and only 2D tracking. The solar farms around me are 2D and the rows are oriented so the panels just need to rotate on a spit. That's not going to work on train tracks and it's a lot of faff for a residential installation. A big solar farm can have repair techs ready to troubleshoot issues. I don't want to bother with the ones on my roof once installed other than period cleaning when needed.

[John Robson]

"Yes, it does. Panels are around 25% efficient with optimal placement both of the panels and the sun, "

No - the efficiency doesn't change with orientation etc.

The thing that changes with orientation is the solar flux.

[MachDiamond]

"We're also increasingly hitting problems of excess production at midday in the summer with no long-term storage and no cheap short-term storage."

A big part of that issue is everybody thinking they'll shove that solar production on the grid and then, profit. It may be better to find ways to use the energy locally. The charger/inverter I just bought will supplement solar with battery when needed and then add grid power to that when needed. Batteries recharge from solar only and solar/battery are priority for the AC output. If solar installations power the trains (partially or fully) with mains being used to make up deficiencies, that might be better. Obviously, any signaling systems would be solar/battery with a fall over to grid power if available.

I've read discussions about wind turbines being used to power ammonia production cells rather than being grid-tied where the ROI seems to work out better. It also lets turbines be installed where there's good wind resources even if there isn't a massive line of pylons ready to take the power to the big city. In the US, there are miles of underground ammonia pipelines so opportunities to plant a turbine, drill a well for water and make ammonia while the wind blows and stick it in the ammonia grid. It's a great example as ammonia production is a huge portion of worldwide electricity usage. I'm sure other applications can be found.

[Chloe Cresswell]

"If solar installations power the trains (partially or fully) with mains being used to make up deficiencies, that might be better."

As the article said: "as solar energy is fed directly into the traction grid." It is being used to power the trains first, yes.

[John Robson]

"A big part of that issue is everybody thinking they'll shove that solar production on the grid and then, profit. It may be better to find ways to use the energy locally. "

And when it's really a problem, that's what will happen.

Octopus already do this in the UK with things like their intelligent Go tariff. When there is plenty of renewable energy flooding the grid they can turn on in excess of a GW of car charging. At some point they'll realise that there are other controllable devices as well (immersion heaters are the really obvious ones).

In winter they have a storage heater specific tariff that will do the same for storage heaters, giving a boost during the part of the day with the best wind conditions.

In countries where there really is a glut the sale price of export drops, and people shift to using the power locally instead. When my solar was installed the export rate was awful, so I didn't export at all if I could avoid it. Now however I'm encouraged to export, so I do.

[Roland6]

A good few years back (probably before CoVid) it was noted a good use of a farm based wind turbine was for fertiliser feedstock production rather than supplying electricity.

Once you have renewable (solar, wind etc.) you do think differently about energy. So whilst we ,might still as for energy efficiency, we can also be energy inefficient, like using more energy intense ways of creating ammonia, hydrogen etc. trouble is this goes against the “big business” ethos of our societies and which governments like because they can more easily levy taxe on consumption…

[MazeFrame]

HVDC is a thing in offshore ties for wind generation, since railway in most parts of Europe runs at 15kV or 25kV (3kV systems are also wide spread), the same HVDC and HV-inverter technology could be used.

Would probably make more sense MPP-wise to bundle them together into 400V AC and then up-convert that to 15kV.

[has been]

The two strings of 7 panels on my workshop roof are essentially horizontal. Yes there is some loss of peak output due to the orientation, but it's really not significant compared with a house roof that isn't facing in the right direction. Peak output appears to be about 80% of theoretical maximum even in the UK Midlands. Ambient temperature has a larger effect than that (Lower than optimum out during the recent hot weather).

[John Robson]

Interesting data point... I have a fair area of flat roof which could be quite interesting to cover... but it is three storeys up, so there are some installation and maintenance challenges

[Roland6]

From my south facing roof in the UK Midlands a bigger factor seems to be clouds. You may think we’ve had a couple of weeks of clear blue skies but my daily production charts show otherwise.

[phuzz]

Most house roofs are also at the wrong angle, but panels are still cheap enough that it's worthwhile

[cyberdemon]

Indeed. I have a flat roof garage with 16 120W panels that cost me £50 each, i'm perfectly happy with the 900-1200W that it produces for 6-8 hours a day. It's enough to fully offset the small aircon that I have in the house. If they can do 8kWh/day for 400 days (ie maybe 2 years), they will have paid for themselves

[Charlie Clark]

So, this is just the cost of the panels without installation. What about the inverter and a battery?

[Roland6]

My 14 panel roof iand 17KWh battery pack installation was a little under £20k. According to the calculator, the installer guaranteed a minimum return on investment of 16 percent Pa for 30 years, after allowing:for investor and battery replacement at circa 15 years. Currently achieving well above this, which means my break even point is falling and is now trending towards circa 5 years.

[HereIAmJH]

Another advantage; ability to provide power where there is no grid connection. The railroads use signals and communication every where along their routes. This is how SPRINT was born. If they provide some backhaul, they could also support cell towers in remote areas.

[retiredFool]

Know what you mean. Adding parking covers or just panels on existing covers to employee lots seems to be a no brainer. Multiple benefits, employees get covered parking so no hot car, they could siphon off a bit of the power for employee recharging of their car during the day, excess could be used to offset the co power usage.

[gryphon]

Problem is it's quite a big CAPEX with payback over 5-7 years.

£2500-£4500 per parking space

Plus no guarantee you'll be able to sell excess power to the grid (apparently a lot of DNO's are constraining feed-in due to infrastructure issues) so would either need to curtail it when required or make a massive investment in battery storage as well.

[Charlie Clark]

I think the CAPEX point isn't made often enough and it gets worse if you start to add charging infrastructue. We've got used to, possibly artificially cheap, Chinese panels and the vestiges of feed-in tariffs, that we think this is how things are always going to be. But if you don't have a use for the power you're producing and can't sell it, then the economics can start to look very different. Of course, car parks themselves are an example of how extremely wasteful cars are…

[John Robson]

Car parks tend to be adjacent to workplaces, where power is being used... Not hard to find local use for quite alot of power 5 days a week.

[retiredFool]

I'm just not of the belief that China is subsidizing everything like the press/gov seems to push. I think the difference is China is willing to accept margins of 5% while the west wants 50+%. I'm always reminded of shark tank where someone pitches an idea, product is made in the US, and the sharks always want to make it in China/Vietnam/? to boost the margin from say 15% to 40%. Greed is good in the west.

[HereIAmJH]

It's also labor costs are cheaper in emerging markets. That lowers the price of everything. But they also don't need to earn as much because their living expenses are lower. A quick google search says the cost to live in Shenzhen is $1000 USD/mo. Where I live it says it would be $2500. $550 one-person rent vs $1650. Food here is 2.5 times as much. If you move your factory to a more rural area you can reduce labor costs further, but you might lose the savings to transportation. And then there are the questionable labor practices....

[retiredFool]

That is nonresponsive though. My point was the idea being pitched was making money. 15%. A reasonable return really. At least I'd be happy with 15%. And your response was just I could make more by shifting to a lower cost country letting go of all the US workers. Greed like that is why the US is going into the shitter. Low end manufacturing is always going to have low returns. But without low end manufacturing, you are dependent on foreign labor for critical stuff like PPE. Or rare earth processing. Or any number of things that have to get done in a functioning society. Not everything is rocket science with astronomical returns.

[MachDiamond]

"Adding parking covers or just panels on existing covers to employee lots seems to be a no brainer."

Most of the schools around me have parking covers, but I've never spotted any charge points for EV's. It might also make sense to have the busses live at the school rather than a depot the bulk of the time and recharge from the school's solar canopies. If all the busses for a school district live at a central location, it would take a big solar installation there to charge them all. On dark days, busses could charge from the grid in the wee hours when the campus is using very little of its connection.

[lglethal]

Just one small point - Nothing precludes us from having BOTH solar panels on roofs and solar panels between the rails. There is no shortage of panels being fought over (not like memory chips and those a$$holes in AI!). So we should encourage all options.

A lot of roofs and parking garages are not really designed or safe enough to install panels on. So whilst I personally think every new build should be forced to add panels, a lot of old places cannot have the install done without either a) a huge risk to the installers, or b) a lot of work on the roof to make it safe/solid enough.

Finally, whilst I love the idea of between the rails solar production, keeping it from being ripped up for the wiring would be next to impossible. The railways spent a ton switching over to Fibre Optic because of the number of times the copper got ripped out. This would just be putting Copper back in, and we will be back to the same bollocks with the a$$holes ripping it back out...

[MachDiamond]

"Remember the company that wanted to build roads out of them? "

Solar "freakin'" Roadways

[Anonymous Coward]

No, the real challenges are technological and economical

Anyone who still thinks this is a good idea (or solar panel roads for that matter) should read this excellent thread on Mastodon. It’s a tech bros scam fantasy.

Solar power is great, and by far the cheapest source of energy available, let’s use it where it makes technical and economic sense, not in these poorly thought through projects.

[Yet Another Anonymous coward]

Re: No, the real challenges are technological and economical

Like replacing Golf Courses

[cyberdemon]

Re: No, the real challenges are technological and economical

Or if you have a permanently air-conditioned building with a large flat roof, like one of those Warehouse-turned-Supermarkets, it should be almost mandatory to install panels.. Because in those cases they will also assist in keeping the building passively cool, by keeping direct sunlight off of the sheet steel roof

However it is not quite a simple case of "the more solar we can install, the better" - see https://www.theguardian.com/environment/2026/jul/12/solar-farm-forced-to-shut-derril-water-biggest-grid-overload-fears

The National Energy System Operator (Neso) is understood to have ordered National Grid to shut a vital “super grid transformer” over the summer to prevent the rooftop solar in the area from driving the transmission network’s voltage beyond its safety limits.

The surge in rooftop solar power is particularly difficult to manage during the summer when long, sunny days lead to more generation than a local grid might need.

Basically, the speed of adoption of solar is outpacing the development of the electric grid, several times over. Naiively installing solar everywhere as fast as possible puts a strain on supergrid voltage control, risking incidents like Iberia last year or the one at Heathrow.

The worst offenders are "solar farms" on agricultural land, and land that could otherwise be used for parks, reforestation, or buildings. If we could only relocate those panels onto rooftops (and install more localised storage to take the load off the grid), we could have the cake and eat it.

[CountCadaver]

Re: No, the real challenges are technological and economical

Cut the unit cost of electricity down to the lowest cost producers and I'm sure the public / industry will resolve the issues of oversupply

[cyberdemon]

Re: No, the real challenges are technological and economical

Not necessarily, because "the grid" isn't a single bucket that you can just add power or take power at any location as much as you like. It's a complex network and it has bottlenecks i.e. substations and transmission lines. Substation transformers currently have lead-times extending to a decade for the really big ones, and sometimes 7 years even for the small ones. Three reasons for that: 1: Every country is simultaneously trying to increase electricity capacity for Net Zero, EV chargers, Heat Pumps, Solar farms etc. 2: AI datacentres need a lot of transformers, even if they have their own generators and 3: War in Ukraine and elsewhere has caused both an increased demand for replacement transformers, and a drop in manufacturing capacity..

Oh and 4: particularly in the UK, the grid infrastructure such as substation transformers is very old, much of it commissioned in the 50s and 60s, and is reaching its end of life, right at the time when global availability is lowest, and UK domestic manufacturing has ceased

Much of the "cost" of electricity in the UK actually comes from "constraints" ie paying renewable generators to switch off! And other costs come from having to pay for balancing actions and fast frequency response, due to our increasingly low-inertia grid.

It's a fallacy that the energy cost could be reduced to that of the lowest cost supplier - that would only be possible with abundant Long-Duration Energy Storage, and that's an eye-wateringly hard, impossibly expensive problem at utility scale

[MachDiamond]

Re: No, the real challenges are technological and economical

"Oh and 4: particularly in the UK, the grid infrastructure such as substation transformers is very old, much of it commissioned in the 50s and 60s"

If the branch a substation is feeding has people feeding in their excess solar, it should be taking load off of the substation. Going the "wrong" way isn't what those systems were designed to do, so there is too much of a good thing.

[John Robson]

Re: No, the real challenges are technological and economical

There is - but we're also perfectly capable of resolving that "problem" using flexible demand. The power is locally generated, and if my neighbour has excess solar then I should be encouraged to run the washing machine whilst they export, or indeed heat up my hot water cylinder, or charge the car, or whatever flexible electrical load there is.

[Ian Johnston]

Re: No, the real challenges are technological and economical

How, precisely, do you think that will motivate generators to price their supplies?

[retiredFool]

Re: No, the real challenges are technological and economical

I think one of the problems is where the solar inverters set their cutoff points. I think mine are set at 265 and really they should start tailing off closer to 248. I know no one including me is going to like getting curtailed on power production, but seems reasonable to do. It would also push people like me into adding some battery that was smarter about weather and would delay charging to the likely curtailment time instead of what I expect is as soon as the sun comes out. At the moment I have no battery as there is no economic reason to do so the way my utility has billing setup.

They also need to figure out a way to get the price down on solar residential in the US. I don't know why, but it is probably 4X more than what I hear in EU. Simple example, my 10KW solar system was 36K, no battery. I picked up an Anker portable system for 1500 with 800W of panels and 3KWH of battery. If I multiply by 20X to get 30 grand, I'm up to 16KW of panels and 30KWH of battery. Huh? It took 2 guys 1 day to install my panels. Where did the 36 grand go?

[cyberdemon]

Re: No, the real challenges are technological and economical

Interesting point about voltage cutoff levels..

From a control theory point of view though, a cutoff at 248V is still a discontinuity, which presents a nonlinear ie difficult to model behaviour of the system. If the local grid is excessively back-fed by solar and the voltage rises to 248V and then suddenly all of the inverters trip off, then the substation sees a massive increase in load and ends up in the opposite dangerous condition. It would perhaps be better if the inverters would gradually ramp down their output as they approach the voltage limit. But even then, with an excess of solar in a particular area you could still end up with a situation where the local grid voltage begins to oscillate between two levels

Also FYI, my £50/120W panels that I mentioned earlier are DIY installed. If my garage burns down, I probably can't claim on insurance. But so-called professional solar installers charge a pretty penny and insist on expensive ways of doing things.. But as an engineer myself (though not a "Part-P" registered "electrician") I am satisfied that the fuses I have installed would blow if one of the four strings of 2s2p panels were to go short-circuit, e.g. due to an animal on the roof chewing the wiring. It's not impossible that a partial short could occur though, but the wiring insulation is non-flammable and I am willing to accept the risk. If it were on the house rather than the (outbuilding) garage, it would be another matter..

I also have no battery (and no smart meter) and I am fully aware of the impact on my electricity supplier if I am "running the meter backwards" at a time when the wholesale price of electricity is "negative".. :)

[retiredFool]

Re: No, the real challenges are technological and economical

It would not be a problem I don't think. Even if they were all set at precisely 248V, which well, impossible, the voltage drops in the wiring to the houses. transformers from house group to minor distribution group (7.5KV usually) and then the next line loss to the next transformer level above the 7.5KV. It would be a fairly gradual taper, or really a gradual going up and then stopping. I have read though there are some fancy distribution transformers that will step up/dn voltage under varying load. That might get interesting.

You are correct, the city inspected the crap out of mine, well the useless stuff anyway. I have red stickers on the conduit to the roof every 10' reminding people that it is dual fed. Which really it is not. Just like the stickers on the fusebox, the meters, ... Since I'm grid tied, grid goes down, I go down. There is no dual feed. Stupid waste of money. Especially considering the city inspector never bothered to go in the attic where the wires are running from the panels to the outside walls. You know the place that might catch fire and burn down the house. Or leak because of a bad seal. I don't think the inspector got on the roof either. Cush job those inspectors have.

You were probably smart to DIY, but in my jurisdiction, that would be a hefty fine. Must be connected to grid and must be "approved". Even the fire dept wants a signoff on your install if over 10KWH battery. Again, pretty stupid as people have 50+KWH batteries in their EV's parked in their garage. I think the US has gone bonkers on the whole solar install thing. It should not be this expensive. And if I want to go completely off grid with my own solar/battery, I should be allowed to.

[MachDiamond]

Re: No, the real challenges are technological and economical

"I also have no battery (and no smart meter) and I am fully aware of the impact on my electricity supplier if I am "running the meter backwards" at a time when the wholesale price of electricity is "negative".. :)"

From ramblings I've heard where I am, since I don't have an agreement for feed-in with the power company, if I "run the meter" backwards, they will likely cut power. The meter won't run backwards to begin with as it's programmed not to. They would fit a new meter that would if I signed up for feed-in.

I'm also not worried about burning my garage down. I expect that I'm doing a better, more careful job than a commercial company and using higher quality bits. I might add some in-line fuses when I expand the system so it will protect itself better. I'm also building in a lot of margin. Part of that is so I have expansion options down the road if I need them. The incremental cost of going to a bigger wire size is far less than ripping things out and doing it later. I've also been able to find nearly all of the wire surplus at bargain prices. I'm still sorting through a big estate buy from a retired electrical contractor.

[cyberdemon]

Re: No, the real challenges are technological and economical

> From ramblings I've heard where I am, since I don't have an agreement for feed-in with the power company, if I "run the meter" backwards, they will likely cut power. The meter won't run backwards to begin with as it's programmed not to. They would fit a new meter that would if I signed up for feed-in.

You may have just stumbled on the "real reason" for the smart meter rollout right there. So that they can either a) pay you 5p/kWh for feed-in while charging 50p/kWh for consumption or b) pay nothing at all for feed-in and/or cut you off immediately if any feed-in is detected

I have so-far resisted having one. Mine is one of the old-fashioned GEC "bake-o-lite" electromechanical meters with the spinning disc and mechanical clock. Naturally it "pays" me exactly the same rate for feed-in as it charges for consumption. It's like having a free, infinite-capacity battery! Pure delinquency of course as far as grid stability is concerned, but my solar array is small enough that it's pretty rare for i to ever actually move backwards, and my rate of consumption is all still net positive between readings..

Alas they will at some point forcibly replace it, on the grounds that "its calibration has expired". Of course, they could easily come with a calibrated check meter to test and re-adjust the calibration - but obviously they aren't going to do that. They might offer a "dumb meter", but it would just be a smart meter with half-hourly billing turned off, i suspect it would still disallow feed-in.

[MachDiamond]

Re: No, the real challenges are technological and economical

"You may have just stumbled on the "real reason" for the smart meter rollout right there. So that they can either a) pay you 5p/kWh for feed-in while charging 50p/kWh for consumption or b) pay nothing at all for feed-in and/or cut you off immediately if any feed-in is detected"

That's why I bought a charger/inverter that doesn't export. I think it always draws a tiny bit if it's hooked up to the grid, which isn't required. From the perspective of regulation, it's an appliance so it doesn't need permits or permission from the power company to hook up.

My goal has been to get the biggest and most critical items off-grid first. I am required to have electrical service or the city could condemn the property for occupation. Paying the base charge and buying some tier 1 energy is not that bad. It's also good to have it as a back up. I'd like to get down to the grid only being 10% or less of my energy consumption after being able to keep an EV topped up with more travel. There's lots of great places I'd like to drag my big camera to and if travel was next to nothing, I'd do more of that. There's a great dark sky spot 100 miles from my house I'd like to visit more often with my telescope. If I wasn't paying for petrol, I would.

[Roland6]

Re: No, the real challenges are technological and economical

You need the invertor etc. configured to run the house (or selected circuits) when the mains is not present. These last few months it has been nice to be able to run the house and be unaware of the several multi-hour power cuts caused by grid kit overheating in the hot weather. The shame is I now need to do similar with the water supply ie. Revert a modern everything is on the mains to a pre 1990s configuration where everything other than the kitchen cold tap was supplied via a loft tank (fed from the mains)

The invertor draws a little from the grid mainly to sync. It’s AC phase with that of your grid connection.

[MachDiamond]

Re: No, the real challenges are technological and economical

"They also need to figure out a way to get the price down on solar residential in the US. "

That's easy. Half the cost is planning/permits and inspections. At least it is where I am. I have two independent solar systems that are both completely off-grid. My plan is to cover the garage roof once the roof is redone and use the charger/inverter I just got to run everything in the garage with a grid back up. It's zero export and it will supplement with the grid as needed. I plan on putting in a fair amount of battery so I can run the freezer drier full time with no grid unless I have several days of cloud. I'll check the weather before I do a run. The box I got is 3kW and can charge batteries at 80A. I can fit a higher capacity box if it turns out I need it, but it might be cheaper to just use the grid when I need to such as with the welder. I'm not using big power tools all the time so building a system big enough for all of that could be a waste. The unit I got was on special and super inexpensive.

[MachDiamond]

Re: No, the real challenges are technological and economical

"Huh? It took 2 guys 1 day to install my panels. Where did the 36 grand go?"

I expect you had the installation company quote the system. They sold you what they wanted to sell, not necessarily what you needed. A big chunk will have gone to The Man and another to cover insurance. People working on roofs get hurt more than most other trades. A load of Anker portable systems wouldn't be easy to manage.

In plenty of the US, a 10kW system is the cut-off for what's considered "consumer". Above that and the system might be considered "commercial". That jacks everything up. The solar company sold you the biggest system possible before severe complication would have set in. You may have been better off with a 5kW system plus some battery to get you past that evening peak to the point where off-peak rates kick in. It's hard to say without a comprehensive analysis of your usage. If nobody set up a load of current clamps in your panel and captured data for a month, that's a sign.

[HereIAmJH]

Re: No, the real challenges are technological and economical

Ignore the grid. Require solar panel installation where possible, to the degree that it's output is consumed at the source. Those air conditioned Warehouse-turned-Supermarkets use a lot of energy. Both for climate control and food preservation. Even if not required, change regulations to allow installation of solar carports to charge electric cars. My city simply will not allow it currently. They only understand (permit) standard grid tie configurations.

[MachDiamond]

Re: No, the real challenges are technological and economical

"My city simply will not allow it currently. They only understand (permit) standard grid tie configurations."

Easy. install the grid-tied system and change it once it's been signed off.

[MachDiamond]

Re: No, the real challenges are technological and economical

"The National Energy System Operator (Neso) is understood to have ordered National Grid to shut a vital “super grid transformer” over the summer to prevent the rooftop solar in the area from driving the transmission network’s voltage beyond its safety limits."

An easier way to do that is send feed-in tariff prices down the line. An oversupply would lead to a negative feed-in tariff. Anybody with a grid-tied system will quickly have something that blocks export when prices go negative. For EV's, the opposite would be good. Prices sent down the line so owner could decide what price they'd like to pay to charge up their car. When there's lots of supply, prices would be cheap and EV's could take a bunch of the load. When supply is constrained, prices go up and EV owners would only charge if they really needed to. The power companies make money shifting electrons so the more they can utilize their capacity, the better.

[cyberdemon]

Re: No, the real challenges are technological and economical

Yes.. "The Free Market will solve our engineering problem!"

Will it Hell

It just adds a couple more layers of Bork to an already Borked system.. "Prices" do not necessarily reflect the load on the local distribution network i.e. the substation at the end of the road or the bigger one it's fed from. What happens when the servers that set the "prices" are unavailable? How do you protect it from deliberate cyberattacks such as the one the Russians recently attempted in Poland?

> "experts suspected that whoever was behind it attempted to disrupt communication between renewable hardware and power distribution operators."

[Roland6]

Re: No, the real challenges are technological and economical

> Yes.. "The Free Market will solve our engineering problem!"

Yes the free market as operated by the established utilities with investment in traditional power generation plant will sell solar installation, but will size the installation to keep the consumer dependent upon expensive energy - my utility sized my battery system to only cover typical overnight summer usage when energy was typically cheap, not 47 hours of winter usage.

They additionally only offered a miserly rate for the energy I produced,; unlike Octopus Energy who had no generation capacity other than the renewable capacity of their customers…

[Anonymous Coward]

TBH my first thought was that they'll get covered in grease, oil and other associated crap. Does the train give the a sweep / clean as it passes?

Seems like a reasonable idea, the space between rails is pretty much lost and this might be a place to put panels that won't upset anyone and might be mechanically advantageous i.e. you can lay and lift them mechanically just as the article states.

But it might be just as easy to put panels on south facing embankments on the rail route.

[R Soul]

a 100-meter photovoltaic installation on a railway line

Presumably these were electricity meters? Or maybe they're light meters.

[steviebuk]

This seems like

another Solar Roadways scam.

https://youtu.be/fPejBipLuFo?si=Lg0tRNqM9Y9S3cTR

[cyberdemon]

Re: This seems like

"Solar freaking Railways!! (At least they're not putting them under the freakin trains, I hope...)"

Yes, that is a quote, 14 mins into the video you linked!

[mtp]

EEVBlog was not impressed with this idea

EEVBlog looked at this a while ago and was unimpressed

https://www.youtube.com/watch?v=7vItnxhWRqw

https://www.youtube.com/watch?v=o3f9UvYSq9o

He did the numbers on solar roads and it was not pretty - his analysis of solar rail is bad but for more mechanical reasons.

[Phiphi in SoCal]

Would never work in the US.

In the US, the panels would be tagged with graffiti within hours.

Or worse, stolen or have copper wiring removed.

[rgjnk]

Looks like the trial was in the perfect spot

The seem to have run their trial in the middle of a nice straight fast open run of track.

Shame that so much track is curved, or in cuttings, or surrounded by trees, or in places where there's lots of brake dust, or where other infrastructure is in place, or has limited access.

Boil it down to the good stretches where ground mount solar will fit and your useful installation space is much more limited.

Doesn't mean it's totally pointless but the practicalities might be challenging.

[Sproggit]

Re: Looks like the trial was in the perfect spot

The separation between the rails, combined with the tightest turn that is permitted on railway track [which is not that tight] means that there should be plenty of room to fit existing 400W panels with relative ease. Which doesn't address the other problems, but does I think render the specific concern you raise to be less of a worry, even with the narrower gauge of Swiss railways.

[Blackjack]

If every rooftop that gets a few hours of sunlight had solar panels it would do a lot to help with power generation without interfering with railways repairs.

[Sproggit]

Interesting Photo

I note that the picture with the article is one showing railway with an overhead "live" wire for the train to pick up using a rooftop conductor [the ground wire being the tracks themselves]...

But the presence of the pylons required to carry that electrical feed means that lengths of Swiss track have gantries overhead already.

Maybe an alternative approach would be to simply build out a more substantial suspension mechanism for the the live rail - make it from aluminium frames on to which solar panels could be placed "on top".

If this were done, then instead of simply having one row of panels "lengthways" - parallel with the track - it would be possible to lay panels 10-20 units across. It would also make it possible for the orientation of the panels - and their elevation - to be better tuned to point towards the sun... though of course it would only really be viable where the compass heading of the track meant that the panels could be set to point south [you'd need track running east-west for best results].

This would mean that not all track would be optimum for deployment, but, where it was possible, you'd potentially be getting 10x 20x the panel density of the solution taken.

You'd also see a reduction [not elimination] in the amount of dust and soot coating the panels [thought the downside would be that they would be harder to clean].

Interestingly, as the cost of electricity gets steadily higher, this is going to become more and more cost-effective. Bring it on.

[Boris the Cockroach]

My question

is more about speed

As in how fast are the trains running over that, are we talking 60 mph commuter line or a TGV or Eurostar 200 mph line? or maybe that TGV that can hit 300 mph....... they'll have to be bolted down really hard.

However as running speed in the channel tunnel is lower, maybe that could be a good place for them......................

[cyberdemon]

Re: My question

Install them on HS2 then!

[DrewPH]

Switzerland is probably the only country in the world where these wouldn't get stolen within weeks of installation.

[MachDiamond]

Out of the way.

The system efficiency would go way up if the panels were fitting higher up and oriented for the optimum production rather than flat on the ground. Rain would clean them off from time to time rather than just sitting on the panels and cemented the dirt together. Leaves and other plant litter would slide off. Since tracks usually have a service road along side, period cleaning would be easy if the panels are mounted adjacent to that road. Snow would also have a better chance of sliding off rather than it just sitting on flat track mounted panels.

The only advantage that I find to be a reach is that there is sqm of space between the tracks. Everything else seems to be a negative. When every other square cm has been used up, that's the point where, maybe, looking between the rails might be viable.

[Anonymous Coward]

Not viable in the UK

The leaves on the line would soon cover them up.

[Ken Shabby]

Re: Not viable in the UK

Only if they are the “wrong kind” of leaves

[Richard Cranium]

Why between tracks? Why not utilise cuttings and embankments? potentially angled better and snow/leaves more readily cleared (by nature). Apart from that there is often a strip of essentially "wild" unused land either side of the tracks.

[Rogerborg 2.0]

If you can't trust the people whose livelihood depends on selling you their solution, who CAN you trust?

[VeryRealHuman]

Solar freakin' railways!

[BartyFartsLast]

Not comparable

Solar roadways was a grift for government subsidy and it was obvious from the outset it was a stupid idea. .

Solar between rail tracks is quite an interesting idea and would make use of a lot of "wasted" space, if the panel installation machine is also capable of pulling them back up it should be easy to maintain or remove for track maintenance

[EricB123]

A Rediculous Comment Follows

Amtrak?

You were forewarned.