The funny part is, they don't really refute the claims made against them.
For example, they don't know how much the panels for roadways will cost them. But the back of the envelope calculation (for just the glass) is around $60T. That's a hard number to work around. Even if that estimate is off by an order of magnitude, then that's still a ton more than we spend on roads.
Also, they state glass is tougher than asphalt. I don't think anyone was trying to argue that glass isn't harder than asphalt, but rather that given enough wear and tear, their glass panels will likely smooth out and reduce traction significantly. The onus is on them to prove that their surface will last with some legitimate road wear tests.
Finally, they point out that LED lighting is clearly visible in the direct sunlight... well, it is from a direct angle. Again, the onus is on them to show that their LED lane markers will be visible from a natural driver's perspective. More importantly, they'll have to show why it will be important to have dynamic markers on highways to begin with, and that they'll be as effective as existing strips.
Really, I don't think that they answered their critics in any sort of meaningful way. Solar roadways are a sexy idea, but not all that practical when you get down to it.
My biggest concern is short- and long-term traction. I ride a sport-touring motorcycle. A LOT if research has gone into the small patch of rubber meeting asphalt. How is that going to change?
> As you can see, asphalt has a hardness of 1.3, copper has a hardness of 3, iron and nickel have a hardness of 4, and steel falls between 4 and 4.5. As you get closer to diamond, you finally come to glass, which has a hardness of 5.5-6.0. So if anyone tries to tell you that glass is soft, just remind them that even simple window glass is harder than steel. By comparison, it's asphalt that is soft.
Haha, this reply on that particular point is a joke. On the contrary you WANT asphalt to be soft, not hard on the road, because asphalt needs to be elastic. When a large truck goes on your road, you need the asphalt to show elasticity so that it can carry such weight and come back to its former state. Tensile strength and Ultimate tensile strength are the actual parameters you want to look it for such road materials and certainly not hardness. The harder your surface, the most prone it is to break when facing heavy tensions/forces.
> His cost argument doesn't make any sense. He is comparing some mythical 12x12' $10k panels to the same size of asphalt and is magically breaking even.
That stuck out at me as well. He's sort of saying "IF we could make these things for $10k per 144 sq ft section, then it would be cost competitive with asphalt." But then he completely punts on the question of how much it's likely to cost. It's not difficult to make some order of magnitude estimates for the cost of raw materials and the omission of such an estimate (even if just to show that the $10k per 144 sq ft goal is plausible) is, well... odd.
* Maintaining the high-friction surface of the glass as it is worn down
* Keeping the road surface transparent to sunlight as it is abraded away and covered with dirt, motor oil and ground rubber
* Huge energy requirements for melting snow, especially in areas where snow, ice and winter storms would reduce the energy generated by the panels
* The _actual_ cost of their road surface compared to asphalt
I'm quite surprised to see HN as the source for some of the naysayers. Sure, there are a lot of hurdles still in their way, but I don't see why they are insurmountable. This work is definitely more meaningful than the latest advertising algorithm or social graph analysis most of us are working on, even if it doesn't pan out in the end.
I've noticed that HN commentary about non-computing topics start from the "here's why you can't do it" side of the spectrum and stories from the computing world start from the "here's how you can do it." I think it's just the nature of the audience and not necessarily intentional. Even beyond that, engineers tend to be contrarian by default when discussing engineering.
Elon Musk's companies seem exempt to that on HN, though.
This is probably just a side-effect of getting programs to do stuff being more easy and malleable than working with real objects where you have to take physics into account, not something wrong with the audience. The chances of a random engineering idea being impossible is much higher than the chances of a random application idea.
Start with "heating the road" to melt snow. The most efficient way to use sunlight to do this is to turn all the energy we get from it into heat. But wait, thanks to the magic of black body absorption and emission the asphalt already does this. And since it's black it absorbs most of the incoming light that strikes it transforming it to heat.
Yet this isn't enough to melt the snow on the roads, because we have snow on the roads. So somehow replacing this nearly 100% efficient system with one that is about 15% efficient will solve our problems how exactly?
You are allowed to dream as much as you want, but when one of your main applications of what you're touting as a solution breaks two out of three laws of thermodynamics you're selling bullshit.
In one sentence, subtly hinting that there's no possible way you could be wrong and comparing yourself to the great philosophers.
While impressive self-aggrandizing, in no way did I say "be nice" and that's a pretty disingenuous reading of what I wrote. You could have made your point without the little left hook in your text without trying to be nice.
Since you're arguing with me on something I consider to be readily apparent, I can mostly figure out that I'm wasting my time. (And, also, I have a hard time imagining Socrates responding to "I can't see your point of view" with "that's because you're not using your brain, dumbass.")
Unless someone went behind my back and figured out how to use quantum mechanics in macroscopic systems to beat the second law of thermodynamics there isn't a way I can be wrong.
Have you tried thinking for more than 5 minutes? Surely this is not an insurmountable problem. Here, literally the first two things that pop into my head wrt. to this issue:
1. Heat storage: incorporate some sort of long-term energy store that allows us to sink extra energy from the warm season and reclaim it during the cold. We already have this technology, nothing new.
2. Use the warmer areas to power the colder. This thing will create its own power grid, right? So we don't have to rely solely on the one panel to produce its own energy for heating, it can take advantage of the entire network of panels. As long as the entire network of panels is generating a surplus (which back of the envelope calculations say it could), then you're fine.
I'm sure if I spent any real amount of time thinking about it I could find other solutions.
So maybe we can be a little more creative than, "the new system cannot function in exactly the same way as the old system, therefore it is impossible." You are the one being intellectually lazy.
The question isn't is it an insurmountable problem. The question is if it is an economically sound way of doing things.
And the answer is a resounding no just from thinking about conservation of energy: you will need an area of land at least ten times the size of that covered in snow to melt it from the simple fact that turning heat into power to turn back into heat is in incredibly inefficient process and during winter there is more than 12 hours of night in which solar panels don't work. And 100 trillion dollars worth of batteries isn't a solution either.
HNers tend to be technical people who like numbers. It's my experience that such people tend to dislike what might be politely called 'bovine excrement.' The lack of numbers[1] is, I think, triggering some members' "BS meters." In my field (physics), it's common to be challenged to demonstrate how you know something (or why you think something is true). It's a mark of a good scientist/engineer that they can back up their claims (which often involves numbers).
[1] For example, as others have pointed out, the story claims to refute the argument that solar roadways will cost 6e13 dollars... but when you actually read the counter-argument, it basically says "We don't know how much it will cost, it just won't be that particular number."
I thought the premise of the "Solar Freakin' Roadways" video was to pit the solar roadways against a direct competitor like, solar freakin' panels above the roadways.
The real premise is to pit SFR against a sane alternative. Even putting panels above (or alongside) all roadways is prohibitive due to the transmission line requirements ($1 - $2 million per mile).
There's far more to be said for siting solar where you use it (e.g., on top of roofs, buildings, parking structures, etc.), or where the siting is optimal, in concentrated locations. Because it turns out we're not hurting for space to put solar cells, but rather, we need to get the costs down. A 100 mile square of solar collectors in the desert would more than provide for all electrical generating needs for the US, and you'd have a small set of long-distance transmission lines from it.
I'm not seeing many actual rebuttals here. I don't have a hell of a lot of context because I don't know what the exact initial claims were, but take this:
"False Claim: we can't afford to heat roads"
Their response doesn't actually talk about the feasibility of heating roads. They don't mention how much energy their solar panels will have stored before a snow storm, and whether or not it would be sufficient to melt lots of snow.
My half-assed guess is that there's maybe enough energy in theory to melt an inch or two of snow, but they don't really provide sufficient detail:
(From their website):
"Currently, the full size hexagons are 36-watt solar panels, with 69-percent surface coverage by solar cells. This will become 52-watts when we cover the whole surface when we go into production. When we add piezoelectric, they'll be capable of producing even more power. Also, as the efficiency of solar cells increase, more power will be converted.
We tested the heaters over the winter with a DC power supply that provided them with 72-watts. This was an overkill and made the surface warm to the touch on most winter days. We still need to experiment with different voltages at different temperatures, to determine the minimum amount of power required to keep the surface above freezing. Remember, they don't have to heat up to 85 degrees like the defroster wire in the windows of your car: they only have to keep the surface warm enough to prevent snow/ice accumulation (35 degrees?)."
You need what, like 300 Joules to melt a single gram of ice/snow/etc. So their 50W panels could melt a gram of water per 6 seconds.
I can't figure out how big the panels are, but their website seems to say 4 square feet. So each 2'x2' square area (hexagon, whatever) can melt 0.166 grams of ice/snow/etc per second.
Say you get a hypothetical snowfall of 2" (not very damn much for some areas). That's 4 ft * 2 in of snow, or 2/3 of a cubic foot. That's about 10 pounds of water in solid form, or 4.5k grams. So assuming their 50W panels are 100% efficient at melting snow, it would take their accumulated energy about 8 hours to melt the snow. (Of course please check my math, I might be off by an order of magnitude on either end here)
That seems at least theoretically possible, but there's no discussion about how much energy a panel can store, or other factors that would weigh in here. There's no actual technical discussion whatsoever for that matter. So I was kind of disappointed by the article.
Edit, sorry: 'It would take their panels about 8 hours to accumulate the energy necessary to melt 2" of snow' (That's at least somewhat in the realm of possibility, though for many areas 8 hours of direct sunlight during the winter ain't happening, and a guarantee of a max of ~2" of snow in a day also ain't happening)
1. I have a steep driveway, and when it was poured I looked into putting a heating element in it for about 20 feet to keep the ice off. I don't remember the details, but it was a fantastic amount of money to do it, and required special heavy amperage power connections. I abandoned the idea.
2. If using heating elements was cost efficient to keep ice off, you can bet the military and civilian airfields would use it to keep the runways clear. They do not. My father used to work at an Alaska military airbase, he said that snow and ice removal on the runway was a 24/7 operation. They weren't fools, if the heating element idea would work they'd have used it.
Yea I'm mostly agreeing with you. I just mean numbers wise it might not be strictly impossible to do (except in places where you get >2" of snow, in which case it might actually become strictly impossible). I make no claims towards its feasibility :P
Not that they provided any actual data for us to tell if it is impossible or not.
Edit: hell, they don't even make a cost comparison to putting regular old solar panels next to the road, instead of baked into the road, and using the energy from that to do whatever fancy shit.
The question I have is how different the solar roadways, designed with this in mind, would behave from running heating elements through concrete or asphalt? Could they get an order of magnitude difference?
A couple of things: I think your calculation seems high. Ten pounds is very heavy for 2/3 ft^3 snow (but it would apply for freezing rain, I suppose).
More importantly, there is no reason the roads couldn't draw energy from the grid at times. Being subject to snow is very different from 24x7 snow all winter. If it is providing energy 80% of the time and drawing 20%, it may still be a net positive, especially when combined with enhanced safety and removing the winter maintenance budget line items (well, reducing, anyway).
In winter time, the sun is low in the sky and not up for that long. There's no way it would be providing energy 80% of the day. More like 25%. And with the sun low in the sky, and the road isn't tilted to face the sun, it's hard to see how it would generate much.
First, the 80% number is a number I pulled out of a hat. Second, why does it have to be constrained to that day? Why not (effectively) bank it in the summer and use it in the winter?
Well, we do. It's just that the methods involve a lot of loss.
Plants store solar energy as hydrocarbons. Further reformed into coal, oil, and gas, that's what we use today.
It's possible to synthesize hydrocarbons from seawater at a net efficiency likely around 50%. Hydrogen electrolysis is the primary energy cost at 60% energy delivered on input.
Run that from solar cells at 20% efficiency and you've got a net delivery of 10% of input solar as stored hydrocarbons. Mind that you're only going to extract about 30-40% of that as useful work or energy (electric generation is about 38% efficient in fuel conversion, cars around 10-20%, IC engines generally about 30%).
But the neat thing about hydrocarbons is that once you've got them, they can store for a long time. Hell, we've got proofs-of-concept showing 300-500 million year viability.
There are other options as well. Some are far more responsive (flywheel kinetic storage, pumped hydro), some far more efficient in energy input/output), others have varying degrees of suitability (CAES, thermal energy storage, liquid metal/molten salt batteries). I'm actually starting to see this as a potentially solved problem.
This brings up an problem which hadn't occurred to me until just now: what happens when heavy snow plows come out on these roads with their massive buckets scraping across the glass surface. Surely this will ruin this fancy road?
The "storage" for the solar panels isn't storage. The scam, er, scheme, is at best net-metering. The idea as described would feed electricity generated from solar energy when possible. The heating circuits would draw from grid power. The SR materials and/or video describe this in some detail (as does Thunderf00t's critique).
Okay, got it, glass is more resistant to scratching than steel. Now grind sand and rock against either for days, let alone months or years. It's going to lose its optical qualities. Bad optics, no sunlight, no energy or LED light.
I _love_ the idea of a smart roadway that helps pay for its self. But I don't think this design hits the mark yet.
> One unscrupulous individual even took our viral Solar Freakin' Roadways video (by volunteer Michael Naphan) without our permission, and has used it to create another video, in which he has embedded deliberately misleading information. He is even making money by placing advertising on it to make a profit!
The funny thing is that they don't actually counter any of his claims, just mention everything that is wrong with the current system and say how it will be wonderful if that wasn't the case.
Yes, it would be wonderful, but when you're not even releasing the information for how much your prototypes cost the "it's going to get cheaper" argument isn't convincing anyone.
Honestly, I thought this was great. They don't have every minute detail figured out yet, but they've generated enough interest to start getting there. I'm just glad they spoke up.
"We are still in R & D, and we haven't even calculated the cost for our prototype. That will come next month as we get our final report ready for our Phase II contract with the Federal Highway Administration. And even if we had those numbers available now they would have no relevance to the cost of our actual product.
When you are prototyping, you are buying parts in very low quantities, which is the least cost efficient way possible. When you go into production, you order your parts in the 10's of thousands, greatly reducing the costs. Thanks to our funding from Indiegogo, we are now going to hire a team of engineers this summer, who will help us make tweaks to the design, streamline production and get costs down. At that point, we'll be able to release cost information.
But right now, not even we have that information, so if you read an article where a journalist claims to have any data on costs, you can be assured that they have not done their homework and are quoting another unreliable source or they are making up numbers."
For an attack on false information, they seem very light on the facts.
> False claim: We picked a really stupid place to put solar panels
They put forward several arguments as to why solar roads would be a good idea. The problem with this is that it does not address the opportunity cost - the argument should not be why solar roadways would be good, but why solar roadways would be better than solar rooftops or solar fields. The complete lack of figures here is not helping them.
> False Claim: Solar Roadways is going to cost $60 trillion dollars
OK, so it won't cost $60 trillion, so what will it cost? Again, no numbers, no estimate, just "we don't think it will cost $60 trillion, but we can't substantiate why"
> False Claim: Asphalt roads are cheap and maintainable
Not going to argue the claim (whether it is true or not). But what research have you conducted into how Solar Roadways would be better, other than the (unsubstantiated) claims that the roads will pay for themselves.
> False Claim: we can't afford to heat roads
They lead with ""Over 70 percent of the nations roads are located in snowy regions, which receive more than five inches (or 13 cm) average snowfall annually. Nearly 70 percent of the U.S. population lives in these snowy regions". Then follow up with "Each year, 24 percent of weather-related vehicle crashes occur on snowy, slushy or icy pavement. Over 1,300 people are killed and more than 116,800 people are injured in vehicle crashes on snowy, slushy or icy pavement annually." Finally concluding with "Does the current system of snow removal sound cheap to anyone? What would saving over 1300 lives and preventing over 115,000 injuries per year be worth? Not to mention medical bills, vehicle repair, lost wages, etc."
I am sorry, but that is not how it works. That is nearly implying that no one will ever die on a solar roadway. I agree that there may be benefits, but the article has used statistics in a way that is meaningless.
> False Claim: Glass is softer than asphalt
Where to start on this. Hardness is a horrible characteristic to choose a road surface for. Sure, glass may be harder, but will it be more durable? Cracks, structural weaknesses and fractures all will cause problems in glass if all you are worried about is hardness. It's been a while since high school science, but I still remember this. Asphalt doesn't need to be hard, as if it is scratched or compressed, there is just more road base beneath it.
There are many more problems with that article, but that should do for now. I am amazed that Solar Roadways would publish a rebuttal article in this style that is so light on the facts and that chooses claims selective to their cause (such as the hardness of glass). I feel sorry for those that have committed on Indiegogo if the calibre of the author is indicative of the calibre of the company.
Despite all of the above, I will give them credit for using "Clearin' the freakin' air" as a title for the article
So, they respond to numerous fairly well founded accusations that their 'idea' is laughably lacking in solid analysis with... a cherry picked selection of accusations and rebuttals which are also laughably lacking solid analysis.
My favorite part is where they used, as a defence to accusations that their idea won't fly commercially: "We are still in R & D, and we haven't even calculated the cost for our prototype".
Riiiiight. They haven't even calculated the cost of their prototype, but you can totally trust their claims that the product will pay for itself. I wonder what assumptions they've made about future energy prices. My guess - none at all.
It saddens me to see how much this (obviously terrible) idea has caught on in the general population. Science literacy should be a higher priority for our education system.
This really is a textbook case of how not to respond to criticism. There's a little bit of everything. You've got the incredibly bad misunderstanding of fair use:
> One unscrupulous individual even took our viral Solar Freakin' Roadways video (by volunteer Michael Naphan) without our permission, and has used it to create another video, in which he has embedded deliberately misleading information. He is even making money by placing advertising on it to make a profit!
The paranoid delusions:
> the naysayers began coming out in force trying to grab some attention. They use non-scientific "facts", misquote and mislead, and sometimes flat out lie. They write unprofessional articles and create deceiving videos to lead people astray... And there are other journalists who have written articles with really irresponsibly misleading information.
The labeling of other people's cost figures as "false" when they admit they have no idea whether they are false or not:
> We are still in R & D, and we haven't even calculated the cost for our prototype.
Presenting a false dilemma: either heat the roads or your children will die:
> Does the current system of snow removal sound cheap to anyone? What would saving over 1300 lives and preventing over 115,000 injuries per year be worth?
(No mention of the original context of the criticism, which was that heating roads are expensive relative to plowing the snow, the existing way we get snow off roads)
Presenting a traffic light as evidence that LEDs can be seen in bright sunlight, completely forgetting the fact that traffic lights require sun visors for the sole purpose of making the LEDs visible. Not to mention that they have Fresnel lenses, louvers, and all other kinds of special engineering that makes them visible in sunlight. No mention of what kind of analogous techniques they will use. And a picture of the LEDs in a very dark room, to drive the point home that they will work in sunlight, trust us.
A claim that glass is a suitable material for roads because of its moh's hardness rating. By that logic, tungsten carbide wedding rings would be indestructible, and in reality, one bad drop from waist height can destroy them [0]. This is an an argument so bad I can't believe an actual scientist wrote it. Hell, Wikipedia even says in the first paragraph "the Mohs scale is not suitable for accurately gauging the hardness of industrial materials." This argument doesn't even reflect a first-paragraph-Wikipedia-level understanding of the topic.
Long discussion of the troubles of the existing road system with the hidden implication that pretty much anything would be better (except, you know, all the stuff that would be worse).
Seriously, this is really, really bad. I was hoping they had some novel surface protectant they would pull out and say "sure, this would be bad with ordinary glass, but we've got this special coating that is cheap to produce and will change materials science and we're putting it through final testing now." But no, they literally intend to do this with off-the-shelf tech, appeal to a hardness argument that wouldn't pass a high school chemistry test, and brand everybody who disagrees with them as "irresponsibly misleading" "naysayers".
I just think this project is a classic scam. It won't work even if they produce numerous astounding technical breakthroughs. It reminds me of the people who are creating cars that run on tap water.
> Presenting a traffic light as evidence that LEDs can be seen in bright sunlight, completely forgetting the fact that traffic lights require sun visors for the sole purpose of making the LEDs visible. Not to mention that they have Fresnel lenses, louvers, and all other kinds of special engineering that makes them visible in sunlight. No mention of what kind of analogous techniques they will use. And a picture of the LEDs in a very dark room, to drive the point home that they will work in sunlight, trust us.
And LEDs have limited view angles. When I look at the LEDs on a traffic sign I get a good view angle. LEDs embedded in the road would be at a poor angle for viewing.
The more I hear from the Solar Roadways people, the more incompetent (or scam-artisty) they sound.
I'd written an earlier critique after a bunch of posts sprouted on G+ and reddit: "Solar Roadways": either a scam or gross incompetence" http://redd.it/26on7y
As to this "clearing the air", it just reinforces that position.
"The point is that our highway infrastructure is in an embarrassingly antiquated state and the U.S. is no longer able to keep going with our current system of asphalt roads." These clowns keep dragging their goalposts all over the field. First it's cheap solar, now it's "the roads will pay for themselves" and "we need rugged infrastructure". The problems with this:
• Solar infrastructure which cannot pay for itself cannot pay for roads in addition to itself.
• There's an existing ruggedized highly-durable efficient roadbed technology for long-haul passenger and freight traffic. It does away, incidentally, with asphalt. It's called railroads: steel rails on wooden sleepers and gravel ballast.
"Solar Roadways is going to cost $60 trillion"
(NB: "dollars" is redundant if you're using the "$" symbol).
The $30-$60 trillion figure was arrived at using commercially available pricing for tempered glass. If Solar Roadways believes they can beat this cost estimate, the first thing they need to show is a cost of glass well below $300 per m^2 as Thunderf00t cited in his debunking video. That should be trivial. And yet they haven't.
"Asphalt roads are cheap and maintainable"
The question isn't "are present highways cheap or expensive?", but "does Solar Roadway's scam, I mean, scheme, actually beat those costs". I can point to all sorts of troubling things in the world, but unless the alternative I propose is actually BETTER then all the hurt presently felt doesn't improve my proposal one whit.
"We can't afford to heat roads"
Again, Thunderf00t: scraping snow and ice off of roads, and allowing blacktop to absorb solar radiation and converting it to heat with an efficiency of 100% to melt the remaining snow and ice is VASTLY less energy-intensive than applying heat of fusion to ice to convert it to water.
Again, SR's scam, erm, scheme, defends its proposal based on the undesireableness of the present situation, not on any actual merits of their proposal. For it has none.
On glass vs. asphalt: the question isn't the hardness of the materials, but on the durability with the added proviso that the material serve all its functions.
Asphalt has the primary requirement of remaining asphalty.
Glass would have to exhibit both the durability of asphalt and sufficient transparency to permit solar radiation to be absorbed and LED signals to be emitted.
Speaking of LEDs: the rebuttal fails to mention the most significant of Thunderf00t's critcisms:
• That much roadside signalling can occur with zero electronics or power requirements through passive reflectors. As is done today.
• That static, horizontally-mounted signage is sufficient for virtually all other circumstances. Where periodic signage changes are necessary (e.g., road closures), flippable signage can be used.
• If dynamic information is necessary, that can be provided with occasional electronic signboards, raised above the roadbed (for increased visibility) and with optimally targeted and shaded LED lighting (or variable reflective displays), which are fully legible in daylight. And at vastly lower cost than resurfacing every last inch of roadway in the nation.
And the rebuttal utterly fails to address the transmission line costs: $1 - $2 million dollars per mile, across the 23,000 miles of roadway, for another $23 - 46 billion dollars of...
> On glass vs. asphalt: the question isn't the hardness of the materials, but on the durability with the added proviso that the material serve all its functions.
They don't mention "flex". Hard things tend to be brittle. Having the only flex happening at the edges of the panels is suboptimal - that's where all the connectors are.
There's also the matter of fatigue. Aluminum, for example, is far stronger by weight than steel, but it is subject to fatigue in which microscopic cracks accumulate. These can often compromise virtually all the strength of a component before they're visible to casual observation (they can be detected via microscopy, x-ray, and sonic analysis).
I've had several aluminum components fail on me, suddenly, on bicycles. The experience is ... not particularly heartening.
Glass is similarly not known for being highly flexible or self-healing. Among the benefits of asphalt is that it has little internal structure and does reflow to an extent (more so under hot weather, often to the point of creating a hazard). Given the punishment taken by roads, this is a significant benefit.
This is a great idea for a start up. A service for debunking non petroleum technology.
All it takes is a bunch of internet smart nay-sayers with a telemarketing script. From looking arround here the debunking doesn't even have to be good. The appaling quality of it has my eyes rolling with dollar signs. People believe anything(!!??), all it takes is to announce yourself to be an expert who use to work in solar roads, then explain the futility of it all; Make sure to drape it with so much negativity that the positive discussion is drowned out. Like taking candy from a baby.[1]
Given the exponential growth of the solar industry[2] the damage control has exponential effect. Something has to be done if the people with money want to continue bleading the little guy dry. How are we going to heard the little peoples children into our military bases if they can just tap energy from the sun? If you give them any time to themselves they will get all sorts of ideas of their own, stuff revolutions are made of, potentially disasterous. Say people notice their cars are much to heavy for the new road? We would not just loose big on our roads made from oil, our whole swindle could come down like a house of cards. They could very well all change into communists, then we would have to take other liberties and put them all down.
My business would be like a glorious beacon of hope, saving the little people from themselves.
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[ 3.6 ms ] story [ 169 ms ] threadFor example, they don't know how much the panels for roadways will cost them. But the back of the envelope calculation (for just the glass) is around $60T. That's a hard number to work around. Even if that estimate is off by an order of magnitude, then that's still a ton more than we spend on roads.
Also, they state glass is tougher than asphalt. I don't think anyone was trying to argue that glass isn't harder than asphalt, but rather that given enough wear and tear, their glass panels will likely smooth out and reduce traction significantly. The onus is on them to prove that their surface will last with some legitimate road wear tests.
Finally, they point out that LED lighting is clearly visible in the direct sunlight... well, it is from a direct angle. Again, the onus is on them to show that their LED lane markers will be visible from a natural driver's perspective. More importantly, they'll have to show why it will be important to have dynamic markers on highways to begin with, and that they'll be as effective as existing strips.
Really, I don't think that they answered their critics in any sort of meaningful way. Solar roadways are a sexy idea, but not all that practical when you get down to it.
Haha, this reply on that particular point is a joke. On the contrary you WANT asphalt to be soft, not hard on the road, because asphalt needs to be elastic. When a large truck goes on your road, you need the asphalt to show elasticity so that it can carry such weight and come back to its former state. Tensile strength and Ultimate tensile strength are the actual parameters you want to look it for such road materials and certainly not hardness. The harder your surface, the most prone it is to break when facing heavy tensions/forces.
He took the dumbest obviously wrong arguments and "demolished" them, while actually ignoring the valid ones.
His cost argument doesn't make any sense. He is comparing some mythical 12x12' $10k panels to the same size of asphalt and is magically breaking even.
That stuck out at me as well. He's sort of saying "IF we could make these things for $10k per 144 sq ft section, then it would be cost competitive with asphalt." But then he completely punts on the question of how much it's likely to cost. It's not difficult to make some order of magnitude estimates for the cost of raw materials and the omission of such an estimate (even if just to show that the $10k per 144 sq ft goal is plausible) is, well... odd.
Elon Musk's companies seem exempt to that on HN, though.
Have you tried thinking?
Start with "heating the road" to melt snow. The most efficient way to use sunlight to do this is to turn all the energy we get from it into heat. But wait, thanks to the magic of black body absorption and emission the asphalt already does this. And since it's black it absorbs most of the incoming light that strikes it transforming it to heat.
Yet this isn't enough to melt the snow on the roads, because we have snow on the roads. So somehow replacing this nearly 100% efficient system with one that is about 15% efficient will solve our problems how exactly?
You are allowed to dream as much as you want, but when one of your main applications of what you're touting as a solution breaks two out of three laws of thermodynamics you're selling bullshit.
This is unnecessary and completely undermined any point you had.
While impressive self-aggrandizing, in no way did I say "be nice" and that's a pretty disingenuous reading of what I wrote. You could have made your point without the little left hook in your text without trying to be nice.
Since you're arguing with me on something I consider to be readily apparent, I can mostly figure out that I'm wasting my time. (And, also, I have a hard time imagining Socrates responding to "I can't see your point of view" with "that's because you're not using your brain, dumbass.")
1. Heat storage: incorporate some sort of long-term energy store that allows us to sink extra energy from the warm season and reclaim it during the cold. We already have this technology, nothing new.
2. Use the warmer areas to power the colder. This thing will create its own power grid, right? So we don't have to rely solely on the one panel to produce its own energy for heating, it can take advantage of the entire network of panels. As long as the entire network of panels is generating a surplus (which back of the envelope calculations say it could), then you're fine.
I'm sure if I spent any real amount of time thinking about it I could find other solutions.
So maybe we can be a little more creative than, "the new system cannot function in exactly the same way as the old system, therefore it is impossible." You are the one being intellectually lazy.
And the answer is a resounding no just from thinking about conservation of energy: you will need an area of land at least ten times the size of that covered in snow to melt it from the simple fact that turning heat into power to turn back into heat is in incredibly inefficient process and during winter there is more than 12 hours of night in which solar panels don't work. And 100 trillion dollars worth of batteries isn't a solution either.
[1] For example, as others have pointed out, the story claims to refute the argument that solar roadways will cost 6e13 dollars... but when you actually read the counter-argument, it basically says "We don't know how much it will cost, it just won't be that particular number."
It's been discussed a lot when it was posted, and the guys who came up with the idea can't address any major criticisms.
There's far more to be said for siting solar where you use it (e.g., on top of roofs, buildings, parking structures, etc.), or where the siting is optimal, in concentrated locations. Because it turns out we're not hurting for space to put solar cells, but rather, we need to get the costs down. A 100 mile square of solar collectors in the desert would more than provide for all electrical generating needs for the US, and you'd have a small set of long-distance transmission lines from it.
"False Claim: we can't afford to heat roads"
Their response doesn't actually talk about the feasibility of heating roads. They don't mention how much energy their solar panels will have stored before a snow storm, and whether or not it would be sufficient to melt lots of snow.
My half-assed guess is that there's maybe enough energy in theory to melt an inch or two of snow, but they don't really provide sufficient detail:
(From their website):
"Currently, the full size hexagons are 36-watt solar panels, with 69-percent surface coverage by solar cells. This will become 52-watts when we cover the whole surface when we go into production. When we add piezoelectric, they'll be capable of producing even more power. Also, as the efficiency of solar cells increase, more power will be converted.
We tested the heaters over the winter with a DC power supply that provided them with 72-watts. This was an overkill and made the surface warm to the touch on most winter days. We still need to experiment with different voltages at different temperatures, to determine the minimum amount of power required to keep the surface above freezing. Remember, they don't have to heat up to 85 degrees like the defroster wire in the windows of your car: they only have to keep the surface warm enough to prevent snow/ice accumulation (35 degrees?)."
You need what, like 300 Joules to melt a single gram of ice/snow/etc. So their 50W panels could melt a gram of water per 6 seconds.
I can't figure out how big the panels are, but their website seems to say 4 square feet. So each 2'x2' square area (hexagon, whatever) can melt 0.166 grams of ice/snow/etc per second.
Say you get a hypothetical snowfall of 2" (not very damn much for some areas). That's 4 ft * 2 in of snow, or 2/3 of a cubic foot. That's about 10 pounds of water in solid form, or 4.5k grams. So assuming their 50W panels are 100% efficient at melting snow, it would take their accumulated energy about 8 hours to melt the snow. (Of course please check my math, I might be off by an order of magnitude on either end here)
That seems at least theoretically possible, but there's no discussion about how much energy a panel can store, or other factors that would weigh in here. There's no actual technical discussion whatsoever for that matter. So I was kind of disappointed by the article.
Edit, sorry: 'It would take their panels about 8 hours to accumulate the energy necessary to melt 2" of snow' (That's at least somewhat in the realm of possibility, though for many areas 8 hours of direct sunlight during the winter ain't happening, and a guarantee of a max of ~2" of snow in a day also ain't happening)
2. If using heating elements was cost efficient to keep ice off, you can bet the military and civilian airfields would use it to keep the runways clear. They do not. My father used to work at an Alaska military airbase, he said that snow and ice removal on the runway was a 24/7 operation. They weren't fools, if the heating element idea would work they'd have used it.
Not that they provided any actual data for us to tell if it is impossible or not.
Edit: hell, they don't even make a cost comparison to putting regular old solar panels next to the road, instead of baked into the road, and using the energy from that to do whatever fancy shit.
The only difference is that the top layer is glass rather than concrete / asphalt.
More importantly, there is no reason the roads couldn't draw energy from the grid at times. Being subject to snow is very different from 24x7 snow all winter. If it is providing energy 80% of the time and drawing 20%, it may still be a net positive, especially when combined with enhanced safety and removing the winter maintenance budget line items (well, reducing, anyway).
Plants store solar energy as hydrocarbons. Further reformed into coal, oil, and gas, that's what we use today.
It's possible to synthesize hydrocarbons from seawater at a net efficiency likely around 50%. Hydrogen electrolysis is the primary energy cost at 60% energy delivered on input.
Run that from solar cells at 20% efficiency and you've got a net delivery of 10% of input solar as stored hydrocarbons. Mind that you're only going to extract about 30-40% of that as useful work or energy (electric generation is about 38% efficient in fuel conversion, cars around 10-20%, IC engines generally about 30%).
But the neat thing about hydrocarbons is that once you've got them, they can store for a long time. Hell, we've got proofs-of-concept showing 300-500 million year viability.
http://redd.it/22k71x
There are other options as well. Some are far more responsive (flywheel kinetic storage, pumped hydro), some far more efficient in energy input/output), others have varying degrees of suitability (CAES, thermal energy storage, liquid metal/molten salt batteries). I'm actually starting to see this as a potentially solved problem.
I _love_ the idea of a smart roadway that helps pay for its self. But I don't think this design hits the mark yet.
If anyone is wondering I think this is the video they are talking about: https://www.youtube.com/watch?v=H901KdXgHs4
The funny thing is that they don't actually counter any of his claims, just mention everything that is wrong with the current system and say how it will be wonderful if that wasn't the case.
Yes, it would be wonderful, but when you're not even releasing the information for how much your prototypes cost the "it's going to get cheaper" argument isn't convincing anyone.
When you are prototyping, you are buying parts in very low quantities, which is the least cost efficient way possible. When you go into production, you order your parts in the 10's of thousands, greatly reducing the costs. Thanks to our funding from Indiegogo, we are now going to hire a team of engineers this summer, who will help us make tweaks to the design, streamline production and get costs down. At that point, we'll be able to release cost information.
But right now, not even we have that information, so if you read an article where a journalist claims to have any data on costs, you can be assured that they have not done their homework and are quoting another unreliable source or they are making up numbers."
> False claim: We picked a really stupid place to put solar panels
They put forward several arguments as to why solar roads would be a good idea. The problem with this is that it does not address the opportunity cost - the argument should not be why solar roadways would be good, but why solar roadways would be better than solar rooftops or solar fields. The complete lack of figures here is not helping them.
> False Claim: Solar Roadways is going to cost $60 trillion dollars
OK, so it won't cost $60 trillion, so what will it cost? Again, no numbers, no estimate, just "we don't think it will cost $60 trillion, but we can't substantiate why"
> False Claim: Asphalt roads are cheap and maintainable
Not going to argue the claim (whether it is true or not). But what research have you conducted into how Solar Roadways would be better, other than the (unsubstantiated) claims that the roads will pay for themselves.
> False Claim: we can't afford to heat roads
They lead with ""Over 70 percent of the nations roads are located in snowy regions, which receive more than five inches (or 13 cm) average snowfall annually. Nearly 70 percent of the U.S. population lives in these snowy regions". Then follow up with "Each year, 24 percent of weather-related vehicle crashes occur on snowy, slushy or icy pavement. Over 1,300 people are killed and more than 116,800 people are injured in vehicle crashes on snowy, slushy or icy pavement annually." Finally concluding with "Does the current system of snow removal sound cheap to anyone? What would saving over 1300 lives and preventing over 115,000 injuries per year be worth? Not to mention medical bills, vehicle repair, lost wages, etc."
I am sorry, but that is not how it works. That is nearly implying that no one will ever die on a solar roadway. I agree that there may be benefits, but the article has used statistics in a way that is meaningless.
> False Claim: Glass is softer than asphalt
Where to start on this. Hardness is a horrible characteristic to choose a road surface for. Sure, glass may be harder, but will it be more durable? Cracks, structural weaknesses and fractures all will cause problems in glass if all you are worried about is hardness. It's been a while since high school science, but I still remember this. Asphalt doesn't need to be hard, as if it is scratched or compressed, there is just more road base beneath it.
There are many more problems with that article, but that should do for now. I am amazed that Solar Roadways would publish a rebuttal article in this style that is so light on the facts and that chooses claims selective to their cause (such as the hardness of glass). I feel sorry for those that have committed on Indiegogo if the calibre of the author is indicative of the calibre of the company.
Despite all of the above, I will give them credit for using "Clearin' the freakin' air" as a title for the article
My favorite part is where they used, as a defence to accusations that their idea won't fly commercially: "We are still in R & D, and we haven't even calculated the cost for our prototype". Riiiiight. They haven't even calculated the cost of their prototype, but you can totally trust their claims that the product will pay for itself. I wonder what assumptions they've made about future energy prices. My guess - none at all.
This really is a textbook case of how not to respond to criticism. There's a little bit of everything. You've got the incredibly bad misunderstanding of fair use:
> One unscrupulous individual even took our viral Solar Freakin' Roadways video (by volunteer Michael Naphan) without our permission, and has used it to create another video, in which he has embedded deliberately misleading information. He is even making money by placing advertising on it to make a profit!
The paranoid delusions:
> the naysayers began coming out in force trying to grab some attention. They use non-scientific "facts", misquote and mislead, and sometimes flat out lie. They write unprofessional articles and create deceiving videos to lead people astray... And there are other journalists who have written articles with really irresponsibly misleading information.
The labeling of other people's cost figures as "false" when they admit they have no idea whether they are false or not:
> We are still in R & D, and we haven't even calculated the cost for our prototype.
Presenting a false dilemma: either heat the roads or your children will die:
> Does the current system of snow removal sound cheap to anyone? What would saving over 1300 lives and preventing over 115,000 injuries per year be worth?
(No mention of the original context of the criticism, which was that heating roads are expensive relative to plowing the snow, the existing way we get snow off roads)
Presenting a traffic light as evidence that LEDs can be seen in bright sunlight, completely forgetting the fact that traffic lights require sun visors for the sole purpose of making the LEDs visible. Not to mention that they have Fresnel lenses, louvers, and all other kinds of special engineering that makes them visible in sunlight. No mention of what kind of analogous techniques they will use. And a picture of the LEDs in a very dark room, to drive the point home that they will work in sunlight, trust us.
A claim that glass is a suitable material for roads because of its moh's hardness rating. By that logic, tungsten carbide wedding rings would be indestructible, and in reality, one bad drop from waist height can destroy them [0]. This is an an argument so bad I can't believe an actual scientist wrote it. Hell, Wikipedia even says in the first paragraph "the Mohs scale is not suitable for accurately gauging the hardness of industrial materials." This argument doesn't even reflect a first-paragraph-Wikipedia-level understanding of the topic.
Long discussion of the troubles of the existing road system with the hidden implication that pretty much anything would be better (except, you know, all the stuff that would be worse).
Seriously, this is really, really bad. I was hoping they had some novel surface protectant they would pull out and say "sure, this would be bad with ordinary glass, but we've got this special coating that is cheap to produce and will change materials science and we're putting it through final testing now." But no, they literally intend to do this with off-the-shelf tech, appeal to a hardness argument that wouldn't pass a high school chemistry test, and brand everybody who disagrees with them as "irresponsibly misleading" "naysayers".
[0] http://www.examiner.com/article/exclusive-handle-with-care-t...
And LEDs have limited view angles. When I look at the LEDs on a traffic sign I get a good view angle. LEDs embedded in the road would be at a poor angle for viewing.
http://www.nytimes.com/2008/05/24/nyregion/24sign.html?pagew...
I'd written an earlier critique after a bunch of posts sprouted on G+ and reddit: "Solar Roadways": either a scam or gross incompetence" http://redd.it/26on7y
As to this "clearing the air", it just reinforces that position.
"The point is that our highway infrastructure is in an embarrassingly antiquated state and the U.S. is no longer able to keep going with our current system of asphalt roads." These clowns keep dragging their goalposts all over the field. First it's cheap solar, now it's "the roads will pay for themselves" and "we need rugged infrastructure". The problems with this:
• Solar infrastructure which cannot pay for itself cannot pay for roads in addition to itself.
• There's an existing ruggedized highly-durable efficient roadbed technology for long-haul passenger and freight traffic. It does away, incidentally, with asphalt. It's called railroads: steel rails on wooden sleepers and gravel ballast.
"Solar Roadways is going to cost $60 trillion"
(NB: "dollars" is redundant if you're using the "$" symbol).
The $30-$60 trillion figure was arrived at using commercially available pricing for tempered glass. If Solar Roadways believes they can beat this cost estimate, the first thing they need to show is a cost of glass well below $300 per m^2 as Thunderf00t cited in his debunking video. That should be trivial. And yet they haven't.
"Asphalt roads are cheap and maintainable"
The question isn't "are present highways cheap or expensive?", but "does Solar Roadway's scam, I mean, scheme, actually beat those costs". I can point to all sorts of troubling things in the world, but unless the alternative I propose is actually BETTER then all the hurt presently felt doesn't improve my proposal one whit.
"We can't afford to heat roads"
Again, Thunderf00t: scraping snow and ice off of roads, and allowing blacktop to absorb solar radiation and converting it to heat with an efficiency of 100% to melt the remaining snow and ice is VASTLY less energy-intensive than applying heat of fusion to ice to convert it to water.
Again, SR's scam, erm, scheme, defends its proposal based on the undesireableness of the present situation, not on any actual merits of their proposal. For it has none.
On glass vs. asphalt: the question isn't the hardness of the materials, but on the durability with the added proviso that the material serve all its functions.
Asphalt has the primary requirement of remaining asphalty.
Glass would have to exhibit both the durability of asphalt and sufficient transparency to permit solar radiation to be absorbed and LED signals to be emitted.
Speaking of LEDs: the rebuttal fails to mention the most significant of Thunderf00t's critcisms:
• That much roadside signalling can occur with zero electronics or power requirements through passive reflectors. As is done today.
• That static, horizontally-mounted signage is sufficient for virtually all other circumstances. Where periodic signage changes are necessary (e.g., road closures), flippable signage can be used.
• If dynamic information is necessary, that can be provided with occasional electronic signboards, raised above the roadbed (for increased visibility) and with optimally targeted and shaded LED lighting (or variable reflective displays), which are fully legible in daylight. And at vastly lower cost than resurfacing every last inch of roadway in the nation.
And the rebuttal utterly fails to address the transmission line costs: $1 - $2 million dollars per mile, across the 23,000 miles of roadway, for another $23 - 46 billion dollars of...
They don't mention "flex". Hard things tend to be brittle. Having the only flex happening at the edges of the panels is suboptimal - that's where all the connectors are.
There's also the matter of fatigue. Aluminum, for example, is far stronger by weight than steel, but it is subject to fatigue in which microscopic cracks accumulate. These can often compromise virtually all the strength of a component before they're visible to casual observation (they can be detected via microscopy, x-ray, and sonic analysis).
I've had several aluminum components fail on me, suddenly, on bicycles. The experience is ... not particularly heartening.
Glass is similarly not known for being highly flexible or self-healing. Among the benefits of asphalt is that it has little internal structure and does reflow to an extent (more so under hot weather, often to the point of creating a hazard). Given the punishment taken by roads, this is a significant benefit.
All it takes is a bunch of internet smart nay-sayers with a telemarketing script. From looking arround here the debunking doesn't even have to be good. The appaling quality of it has my eyes rolling with dollar signs. People believe anything(!!??), all it takes is to announce yourself to be an expert who use to work in solar roads, then explain the futility of it all; Make sure to drape it with so much negativity that the positive discussion is drowned out. Like taking candy from a baby.[1]
Given the exponential growth of the solar industry[2] the damage control has exponential effect. Something has to be done if the people with money want to continue bleading the little guy dry. How are we going to heard the little peoples children into our military bases if they can just tap energy from the sun? If you give them any time to themselves they will get all sorts of ideas of their own, stuff revolutions are made of, potentially disasterous. Say people notice their cars are much to heavy for the new road? We would not just loose big on our roads made from oil, our whole swindle could come down like a house of cards. They could very well all change into communists, then we would have to take other liberties and put them all down.
My business would be like a glorious beacon of hope, saving the little people from themselves.
[1] - https://www.youtube.com/watch?v=90TzRnrV14I [2] - http://theenergycollective.com/eliashinckley/315371/solar-in...