I never managed to see the advantages of having a solar road compared to just having a normal road with solar panels next to it. Or above it. Or literally anywhere else. In fact I can't think of many areas that still get direct sunlight that would make for a worse place to put solar panels than on the road...
The advantage that people wanted to get is that in the end you also get a road.
Roads take up space, cost money to build and maintain. If you build it next to the road the road need twice the amount of space and still require the space, construction and material for the actually road. If you build it above the road you get all the issue of overhead roof on a road (trees that fall on it, wind, height limitation).
In addition to saving money by not actually building a normal road, the idea in most of solar roads projects is that it combines the work of putting internet and power cables into the ground.
That it currently do not work economically is the issue that the article showcase. Maybe it will never work and it always will be cheaper to simply build the road with current construction methods, put internet/power cables under it, buy large lands (farming land?) and construct regular solar parks.
Other concept of combining solar panels and building materials that is argued as more cost effective are roofs on houses. Same concept as solar road, ie that you get a roof and a solar panel in one without spending the work and material for both, but I have no idea if the economics is better than solar parks or if it is cheaper to just build normal roofs and go the route of getting land and building solar parks separately.
So the problem is that a normal road costs on the order of $3 million per mile, and a solar road costs... 10 times as much. And it doesn't last as long.
It is plausible, but how much money is actually saved if you need to build panels that can stand wear and tear of vehicles above them? Surely the engineering is different and more costly than regular panels that don't need to be built to withstand cars rolling over, plus their maintenance, no?
You get two in one but for double the price of both combined and then some. Not to mention the horrible quality and durability of the two things you get.
I have serious doubts these experiments will lead to commercially successful implementations, but I don’t think it is useless to do them.
Reason? Solar cells keep getting cheaper and cheaper. That makes the costs of scaffolding to hold the cells take a larger and larger share of installation costs. In the limit where cells are essentially free, putting cells everywhere there is some large horizontal area will make sense.
Now, of course, we may not get close enough to that limit for this to make sense, cells may be too fragile for mounting in a road, there may be plenty of more profitable places to put solar cells, etc, etc, but that isn’t guaranteed, and we can’t tell without experimenting.
Except we don't actually need that much solar power and ground based installation is really cheap.
Further road surfaces need to be transparent for solar to work, handle high loads, channel water off the surface, and provide lots of friction in a wide rang of weather conditions. It’s an extremely difficult problem, but solving it without massive reduction in panel costs is kind of pointless.
> Colas, the company that built the road, said in 2016 that the solar panels were covered with resin containing sheets of silicon to make them capable of withstanding all traffic.
I'm going to bet they said that after the check cleared.
This was not at all a failure. They built a 1km experimental road. They gained valuable information about real-world performance and technical challenges. It's not as though they built a 100km long six-lane highway with unproven technology. They built a tiny one-lane trial to test a promising idea.
It was overhyped by politicians, but what isn't? Maybe they even steamrolled over engineering red flags. That doesn't mean it wasn't a valuable experiment.
The trouble with this viewpoint is that there are an endless number of things we could be trying, and it's more or less a zero sum game.
The idea was terrible on paper, easily falsified by back of the napkin math. The same amount of money could have been spent on, eg, testing the commercial viability of smoothing out grid loads by making ice off peak for cooling.
The question, when you see something seemingly very dumb, is always "what am I missing?"
It seems unlikely that well-funded scientists are _that_ stupid. It's more likely either that we're missing some reason why solar roads are more efficient at first glance, or that they have some ulterior political motive where wasting the money is intentional. Either way, laughing at them for missing things every internet commenter immediately thinks of seems like a mistake.
That said, in this case, my first thought is, "we definitely haven't run out of better places to put solar panels". The specifics don't matter much when the US has plenty of unused space to put solar farms (even just "next to the roads"). I'm pretty confused by how far the idea's gotten.
There are different reasons to try things, this is worth trying because we have so many roads and using even a part of them for energy production would have an enormous impact.
If you can deduce something from your current knowledge, you don't need to do an experiment for that. Certainly people knew that putting fragile semiconductors under roads isn't the best idea, but they went on and spent time and money. I would call this a waste.
Some people deduced one thing, and others deduced the other thing. There was plenty of excitement about this idea on this very site when it was first proposed. Seeing something once is better than hearing it a hundred times.
On the other hand it could also be a scam and the public money wasted could be used for far more interesting experiments. Experiments that at least make sense on a conceptual level or where we really just don’t know how things would pan out in a real world scenario.
Solar roads are not that kind of experiment. Even given an ideal execution solar roads would give you the combination of suboptimal roads with badly used solar panels.
Unless glas turns out to be a superior road surface (which I doubt) and unless solar panels perform better flat on the ground under a layer of dirt than raised above shadows and with a well adjusted angle (which helps the rain to clean the thing and increases efficiency) — unless all of that, putting solar panels on the side of the roads or roofa will be way more economical and ecological.
This is literally bad design: something that looks good or innovative on first glance, but is totally inpractical and maybe even destructive the longer you ponder about it.
it's like that kid who envisioned that we could clean the ocean of all the plastic by laying a long catching device. but they never bothered consulting people who actually build ships and other seagoing vessels. and they didn't bother consulting people who've actually worked on this problem. I believe the biggest issue is that the plastic tend to float under the surface of the water and this thing floated on top of the water. and then in the end this thing just bunched up after a day, so it never really caught any plastic.
this is the problem when you have rich people pick and choose which ideas gets implemented. rather than having people who are actually intelligent and have experience driving innovations you have a constant flow of bad ideas. inevitable something will work and these idiots will claim that their process actually works. no, it's more like they have the money to afford a lot of failures.
As far as I know solar roads where never a promising idea because they have obvious shortcomings that this trial just confirmed. There are a million better places to put solar panels than under car tires. Once we've exhausted those would could start thinking about solar roadways.
But it wasn't a valuable experiment. Absolutely nothing was learned from it. It's some combination of delusion and fraud. Here's a video from 2014 discussing it: https://www.youtube.com/watch?v=obS6TUVSZds
"The engineers also didn't take into account the effects of leaves, which caused damage and limited the amount of electricity the panels could produce. They also didn't think about the pressure and weight from tractors, two locals told Le Monde."
I have come across quite a few “green” initiatives over the past several years which are extremely questionable in their technicals - and all are taking public money, mostly from European Development Funds in the EU, and from similar bodies elsewhere.
They are usually highly visible, buzzword bingo initiatives. You see these projects in the press - a group grinning in hard hats, a colourful initiative behind them. You go back a few years later and it’s tape and barriers and broken glass and danger signs.
Whether folks start with good intentions but then move on, or don’t have adequate plans for maintenance (which then makes one wonder why funding was granted in first place), or simply see an opportunity to extract wealth from a public body, I don’t know.
An anecdote: a service station near my home in north wales proudly announced that they had received a grant to put on a turf roof, solar and wind power. EU funding. Three years on, and they’ve just announced that they’ve received a grant to do exactly the same thing. Plumbing the Europa site shows that the previous grant was paid, and the project reported as completed - but they never did a thing. I’ve seen the same cycle being pulled elsewhere.
There is such a push for governments to be visibly green that they are spending money on highly visible nonsense. The current elected power gets the boost for snipping the ribbon and providing the funding. Their successor gets a beating over the wasteful failed project.
There are good green initiatives happening, but it’s usually where nobody is looking.
I haven't seen anything from it yet that would convince me that it's not a scam. The fact that there are people defending this after all this time baffles me.
I know nothing of the details here, so this is total speculation, but I can imagine value in going with a solution you know wont "succeed", if the data you get from the failure is valuable. Like, no need to spend money trying to fix the tractor problem if the leaf problem is too severe. If in practice the leaf problem only deteriorates things by 30%, that's different than 80%, etc.
Spending the money to solve problems on your first run is likely to not actually solve all of them.
Then again, this could be a bold exercise in fraud and/or incompetence.
Most solar panels are very inefficient at converting the sun to electricity so they need all the help they can get. Two things solar panels require is to be clean and to be perpendicular to the sun. A solar road achieves neither of those things.
Median strips and easements are a possible siting location.
Shade awnings over car parks another.
The challenge with solar power really isn't sufficient area for siting. It's low-cost installation and low-disturbance environments which ensure long panel life and low maintenance costs.
Solar panels have a useful lifetime of about 20 years, due to numerous degredation mechansims (it's not just one), from fogging of the transparent surface to cracking, glazing from dust and sand, hail impacts, broken circuits, etc. NREL (the National Renewable Energy Laboratory) in Colorado have published research on this.
Engineering low-cost, long-lived, readily installable and replaceable panels would be a generally advisable research direction. Looking for extreme siting locations (e.g., high-traffic highways, or even sidewalks), or even, counterintuitively, greater efficiency, is relatively unimportant as compared to total costs and lifetime.
Those things are necessary to get the opimimum amount of electricity but the point of solar roads is to sacrifice some efficiency for the benefit of having huge amounts of surface area. The amount of paved highway in developed countries is enormous, so even massively inefficient solar roads could supply all the electricity necessary and more.
Go, fire up your favourite sattelite image service and check out how much of a typical urban area is really sunlit streets or parking lots. Bonus points for images where the cars that are present are on it. Ah and in an urban environment count shadows in. And quarter whatever figure you got because of dirt, abrasion and failure.
And now compare them to the areas of rooftops you find. Go ahead and do it.
If we're talking about highways, you can usually find large stretches of empty space immediately alongside them, at least the same width as the road itself.
Help me understand the logic behind taking a PV and stepping on it in the worst possible way, leaving dirt , rubber etc, when every PV that is exposed only to the open air needs regular cleaning / maintainance. And its being frequently under the shade of cars
There is no logic behind it, only blind idealism. Unfortunately the couple who invented solar roads poured a lot of time and money into this idea and couldn't back down. Many people followed their enthusiasm.
I think one of the most difficult things you can do as a person is to be honest with yourself and admit when something has failed or won't work and to abandon it, but stories like this are reminders to really self reflect.
Self-cleaning glass is a fairly mature technology and will work effectively on a rooftop solar installation. That won't work on a solar roadway, which a) needs a textured surface to provide adequate grip for vehicles and b) can't retain any sort of coating due to friction and c) is constantly being covered in axle grease, tire rubber, brake dust and the innards of various wild animals.
The article starts with the wrong assumption that you have to hire people to clean the solar panels. Robots have taken over that job a long time ago, at least for utility scale solar.
For some reason, solar roads are a very aggressive meme (in the classical sense of the word). They capture the imagination and blind people to engineering reality.
Solar roads do not make any sense whatsoever, as you wrote pretty much any other place is better for panels.
They capture the imagination because there are plenty of places you don’t want to build solar panels. Namely places that you want to leave alone for ecological or recreational purposes. If you can take a piece of infrastructure that is pervasive throughout a built environment and give it additional purpose, then you can save on or reduce the land you specify for this purpose.
Does it work? Apparently not, or at least: not yet. We have not successfully accomplished this, but it remains to be seen if this is a case of not yet, or never will. Experimentation yields useful data, even when the experiment is a failure.
So where were the failures? The road was less durable than expected. They didn’t account for falling leaves. They didn’t produce as much electricity as they thought it would. Thunderstorms also damaged the road.
But! It did produce a decent amount of electricity, it did successfully transmit it, and it did function as a road. Colas has given up and chose not to pursue this route anymore, but it isn’t a death sentence for the idea in its entirety. It is a failure of execution, and there will be a lot of failures before there is ever a success. I’ll end this with the caveat that there might not ever be a success, but it is too early to decide that and further experimentation might yield other interesting road construction technologies.
The thing is though that currently most roads are made from asphalt, yet even that is not durable enough and needs to be periodically reapplied, how a glass can compete with that?
Same reason Toyota decided to go with the scam and showed off PV covered Prius https://www.theverge.com/2019/7/5/20683111/toyota-prius-plug... Anybody with the smallest grain of engineering background will immediately spot the deception, but typical off the street person will think its brilliant!
How so? I mean, it's an image of cars driving over something which is kind of delicate.
Perhaps you mean roads with solar panels near them that feed the passing cars energy? Now that at least sounds exciting! (Although it's probably not a great idea either, not enough battery weight saving to be worth it.)
This was obviously never going to work; I think it's far more interesting as a piece of morality theater and/or a psychological ink-blot test. Because who looks at a system like this (individual humans carted around extravagantly in an energy-intensive, 4,000-pound CO2-belching murder machine, on an expensive and space-intensive road created just for them) and thinks, you know what's wrong with this system? It doesn't generate enough energy. Mmm yeah, you're almost right. Sort of like how a violent person doesn't generate enough not-punching-people. Keep going with that reasoning. See if you can use the phrase "in the first place" in your answer.
It's fascinating. Obviously they seem to grasp the system has something wrong with it, and the problem has something to do with energy. But when that line of thought begins to lead them inexorably toward the conclusion that they should actually probably stop driving immediately, like today, they take a quick left turn into something else, anything else, whatever's available and "green" - SOLAR, let's do the solar. That'll absolve our sins. Hence, where do you place the panels? In the road, where the sin occurred.
It's like the dim awareness of our actual transportation/energy predicament, is in the cellar of their subconscious, knocking at the door to enter conscious awareness, but not quite managing to get the person's attention. The mental contortions required to actually like this idea, remind me a lot of the ones required to maintain various states of denial. The fact being desperately avoided of course is that a set of changes far more sweeping and less pleasant than they're willing to admit or allow, are going to be necessary.
Could be, and I suspect that a lot of the actual engineering folks involved would agree 100% on this point. They'd probably also tell you that 5 million for real - world experimental data on the exact ways in which it failed was very much worth it.
Was there anything else worth responding to in the wordy pseudo-psychological insults?
I remember at the time this was announced, I was working at a startup in the solar PV industry. Our collective response on the workfloor was, "wow, that's an incredibly stupid idea for so many reasons". Surprised it took them so long to admit failure.
Readit News
Roads take up space, cost money to build and maintain. If you build it next to the road the road need twice the amount of space and still require the space, construction and material for the actually road. If you build it above the road you get all the issue of overhead roof on a road (trees that fall on it, wind, height limitation).
In addition to saving money by not actually building a normal road, the idea in most of solar roads projects is that it combines the work of putting internet and power cables into the ground.
That it currently do not work economically is the issue that the article showcase. Maybe it will never work and it always will be cheaper to simply build the road with current construction methods, put internet/power cables under it, buy large lands (farming land?) and construct regular solar parks.
Other concept of combining solar panels and building materials that is argued as more cost effective are roofs on houses. Same concept as solar road, ie that you get a roof and a solar panel in one without spending the work and material for both, but I have no idea if the economics is better than solar parks or if it is cheaper to just build normal roofs and go the route of getting land and building solar parks separately.
It's more than that. We simply don't live in a world where physics is in favor for doing this.
Many people have done more than back of the envelope calculations to show this simply was a non starter.
Those (people who took money to build ) push this idea are either ignorant at best and dishonest at worst.
It just does not make sense.
Reason? Solar cells keep getting cheaper and cheaper. That makes the costs of scaffolding to hold the cells take a larger and larger share of installation costs. In the limit where cells are essentially free, putting cells everywhere there is some large horizontal area will make sense.
Now, of course, we may not get close enough to that limit for this to make sense, cells may be too fragile for mounting in a road, there may be plenty of more profitable places to put solar cells, etc, etc, but that isn’t guaranteed, and we can’t tell without experimenting.
Further road surfaces need to be transparent for solar to work, handle high loads, channel water off the surface, and provide lots of friction in a wide rang of weather conditions. It’s an extremely difficult problem, but solving it without massive reduction in panel costs is kind of pointless.
Going down that road leads to solar power satellites, not solar roadways.
I'm going to bet they said that after the check cleared.
Deleted Comment
It was overhyped by politicians, but what isn't? Maybe they even steamrolled over engineering red flags. That doesn't mean it wasn't a valuable experiment.
The idea was terrible on paper, easily falsified by back of the napkin math. The same amount of money could have been spent on, eg, testing the commercial viability of smoothing out grid loads by making ice off peak for cooling.
Trying things helps us move forward
It seems unlikely that well-funded scientists are _that_ stupid. It's more likely either that we're missing some reason why solar roads are more efficient at first glance, or that they have some ulterior political motive where wasting the money is intentional. Either way, laughing at them for missing things every internet commenter immediately thinks of seems like a mistake.
That said, in this case, my first thought is, "we definitely haven't run out of better places to put solar panels". The specifics don't matter much when the US has plenty of unused space to put solar farms (even just "next to the roads"). I'm pretty confused by how far the idea's gotten.
Solar roads are not that kind of experiment. Even given an ideal execution solar roads would give you the combination of suboptimal roads with badly used solar panels.
Unless glas turns out to be a superior road surface (which I doubt) and unless solar panels perform better flat on the ground under a layer of dirt than raised above shadows and with a well adjusted angle (which helps the rain to clean the thing and increases efficiency) — unless all of that, putting solar panels on the side of the roads or roofa will be way more economical and ecological.
This is literally bad design: something that looks good or innovative on first glance, but is totally inpractical and maybe even destructive the longer you ponder about it.
this is the problem when you have rich people pick and choose which ideas gets implemented. rather than having people who are actually intelligent and have experience driving innovations you have a constant flow of bad ideas. inevitable something will work and these idiots will claim that their process actually works. no, it's more like they have the money to afford a lot of failures.
They were warned about this.
I have come across quite a few “green” initiatives over the past several years which are extremely questionable in their technicals - and all are taking public money, mostly from European Development Funds in the EU, and from similar bodies elsewhere.
They are usually highly visible, buzzword bingo initiatives. You see these projects in the press - a group grinning in hard hats, a colourful initiative behind them. You go back a few years later and it’s tape and barriers and broken glass and danger signs.
Whether folks start with good intentions but then move on, or don’t have adequate plans for maintenance (which then makes one wonder why funding was granted in first place), or simply see an opportunity to extract wealth from a public body, I don’t know.
An anecdote: a service station near my home in north wales proudly announced that they had received a grant to put on a turf roof, solar and wind power. EU funding. Three years on, and they’ve just announced that they’ve received a grant to do exactly the same thing. Plumbing the Europa site shows that the previous grant was paid, and the project reported as completed - but they never did a thing. I’ve seen the same cycle being pulled elsewhere.
There is such a push for governments to be visibly green that they are spending money on highly visible nonsense. The current elected power gets the boost for snipping the ribbon and providing the funding. Their successor gets a beating over the wasteful failed project.
There are good green initiatives happening, but it’s usually where nobody is looking.
Spending the money to solve problems on your first run is likely to not actually solve all of them.
Then again, this could be a bold exercise in fraud and/or incompetence.
I'm leaning toward scam, because if it can't handle leaves, it can't handle anything.
Shade awnings over car parks another.
The challenge with solar power really isn't sufficient area for siting. It's low-cost installation and low-disturbance environments which ensure long panel life and low maintenance costs.
Solar panels have a useful lifetime of about 20 years, due to numerous degredation mechansims (it's not just one), from fogging of the transparent surface to cracking, glazing from dust and sand, hail impacts, broken circuits, etc. NREL (the National Renewable Energy Laboratory) in Colorado have published research on this.
Engineering low-cost, long-lived, readily installable and replaceable panels would be a generally advisable research direction. Looking for extreme siting locations (e.g., high-traffic highways, or even sidewalks), or even, counterintuitively, greater efficiency, is relatively unimportant as compared to total costs and lifetime.
Go, fire up your favourite sattelite image service and check out how much of a typical urban area is really sunlit streets or parking lots. Bonus points for images where the cars that are present are on it. Ah and in an urban environment count shadows in. And quarter whatever figure you got because of dirt, abrasion and failure.
And now compare them to the areas of rooftops you find. Go ahead and do it.
(https://phys.org/news/2013-07-solar-panels-worth.html)
https://en.wikipedia.org/wiki/Self-cleaning_glass
Solar roads do not make any sense whatsoever, as you wrote pretty much any other place is better for panels.
Does it work? Apparently not, or at least: not yet. We have not successfully accomplished this, but it remains to be seen if this is a case of not yet, or never will. Experimentation yields useful data, even when the experiment is a failure.
So where were the failures? The road was less durable than expected. They didn’t account for falling leaves. They didn’t produce as much electricity as they thought it would. Thunderstorms also damaged the road.
But! It did produce a decent amount of electricity, it did successfully transmit it, and it did function as a road. Colas has given up and chose not to pursue this route anymore, but it isn’t a death sentence for the idea in its entirety. It is a failure of execution, and there will be a lot of failures before there is ever a success. I’ll end this with the caveat that there might not ever be a success, but it is too early to decide that and further experimentation might yield other interesting road construction technologies.
Perhaps you mean roads with solar panels near them that feed the passing cars energy? Now that at least sounds exciting! (Although it's probably not a great idea either, not enough battery weight saving to be worth it.)
It's fascinating. Obviously they seem to grasp the system has something wrong with it, and the problem has something to do with energy. But when that line of thought begins to lead them inexorably toward the conclusion that they should actually probably stop driving immediately, like today, they take a quick left turn into something else, anything else, whatever's available and "green" - SOLAR, let's do the solar. That'll absolve our sins. Hence, where do you place the panels? In the road, where the sin occurred.
It's like the dim awareness of our actual transportation/energy predicament, is in the cellar of their subconscious, knocking at the door to enter conscious awareness, but not quite managing to get the person's attention. The mental contortions required to actually like this idea, remind me a lot of the ones required to maintain various states of denial. The fact being desperately avoided of course is that a set of changes far more sweeping and less pleasant than they're willing to admit or allow, are going to be necessary.
Could be, and I suspect that a lot of the actual engineering folks involved would agree 100% on this point. They'd probably also tell you that 5 million for real - world experimental data on the exact ways in which it failed was very much worth it.
Was there anything else worth responding to in the wordy pseudo-psychological insults?