Solar roadway looks interesting. The idea is replace asphalt highway system with a robust 3 layer system of high durability plexi or something similarly transparent, solar panels, LED's and capacitors, and on the third layer is a modular power transmission system coupled with things like data transmission and other cabled things.
Now the thing has a couple of features which I'd say are interesting and justify the increased cost even if it doesn't replace all the needs of the power grid as of now. 1st, it would be self maintaining, for you southerners who've only experienced "winter" and not "ass-slapping-cold-winter" roads take a lot of salt and work to deice or clean up after snow fall, and the middle layer's designed to have some power storage for primarily load buffering, but can double as heating system, keeping roads cleaner with less effort.
2nd, the LED's are being planned right now just to replace paint on the current roads, but if they set it up now with some openness in the programming, I could see it being used to also deal with automated cars really well too. I'm betting most of those circuits can be interpreted in ways that describe the road surface, providing some kind of broad analysis of traffic patterns could benefit automatic driving.
3rd, a more robust data infrastructure would help us keep up with other nations with more developed net structures.
So, they describe math that says this could replace the entire current power structure, I don't even care, at the moment I'm pretty sure it'll be a net energy provider, but it'll also have a lot of non-power utility that seems interesting, the curious bits are structural integrity, cars and big-rigs are heavy suckers.
So lets discuss how a modular system like this could have problems and how to resolve them. I'm thinking thermal expansion along joins could be a problem, since they plan on having it being made up of a bunch of sq ft tiles.
edit: They are planning 12 ft by 12 ft squares.
Solar Roadway
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Professor Science
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Solar Roadway
Last edited by Professor Science on Sat Aug 29, 2009 4:10 am, edited 1 time in total.
The pursuit of knowledge is in the best of interest of all mankind.
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Professor Science
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Costs? Well, they're trying to engineer for something with 3 times the life span of regular asphalt so they're aloquating 3 times the construction cost of regular road to get road +, and since it accomplishes all of the features of road and + for what they claim is the same cost, one could argue the + would come off as an a free ancillary, but I'm sure your using a different method for $ calculation.
I'm more interested in methods as opposed to costs at this point myself. Their website goes in pretty deep depth though, so if you want to go rooting yourself, be my guest. It's latish here and I had a tiring day of lectures and lab. I'm off to bed.
I'm more interested in methods as opposed to costs at this point myself. Their website goes in pretty deep depth though, so if you want to go rooting yourself, be my guest. It's latish here and I had a tiring day of lectures and lab. I'm off to bed.
The pursuit of knowledge is in the best of interest of all mankind.
The price per panel they quote is too high. They have not allowed for the cost of installation or supporting structure.
Can they actually build a panel that can take heavy truck traffic and still deliver 15% solar efficiency? I'd like to see the design. The transparent material they plan to use should be very interesting. I hope it doesn't get dirty or scratch easily.
I see no logistics plan.
And how about that storage? Supercapacitors. Whoopee. Do the "gentlemen" have any idea what they cost per watt hour? Currently they run about 5 cents a watt second in volume. That is $180,000 per KWh right there. Not counting electronics. And that assumes they don't lose much capacity as they get cold. With a minus 25 C limit (minus 13 F) they may not endure northern winters. And at plus 85C limit ( 185 F) they are going to be stressed in southern and desert climates.
If this works out (big if) it is going to be a very long term project. First they have to get a module that works. Then they have to make it reliable under load and weather extremes. Then they have to get a system to work over a test stretch of road. Then several roads.
BTW I'm not impressed by the guy's CV. He fails to mention the company he worked for. His degrees seem OK but he "learned serial communications from Bill Gates" please. I'm one ahead of him Andy Grove taught me. I would be more impressed if he was an aerospace guy. Or a highway engineer.
He needs 2 million panels per sq mi. at 1E6 hrs MTBF per panel (under the most daunting environmental challenges - hard pounding in wind, rain, snow, ice, and sun) he will have two panels failing every hour. Forty eight a day. About 350 a week. They better be easy to replace.
This probably deserves some research. It is a long, long, way from prime time.
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Edited to fix math error.
Can they actually build a panel that can take heavy truck traffic and still deliver 15% solar efficiency? I'd like to see the design. The transparent material they plan to use should be very interesting. I hope it doesn't get dirty or scratch easily.
I see no logistics plan.
And how about that storage? Supercapacitors. Whoopee. Do the "gentlemen" have any idea what they cost per watt hour? Currently they run about 5 cents a watt second in volume. That is $180,000 per KWh right there. Not counting electronics. And that assumes they don't lose much capacity as they get cold. With a minus 25 C limit (minus 13 F) they may not endure northern winters. And at plus 85C limit ( 185 F) they are going to be stressed in southern and desert climates.
If this works out (big if) it is going to be a very long term project. First they have to get a module that works. Then they have to make it reliable under load and weather extremes. Then they have to get a system to work over a test stretch of road. Then several roads.
BTW I'm not impressed by the guy's CV. He fails to mention the company he worked for. His degrees seem OK but he "learned serial communications from Bill Gates" please. I'm one ahead of him Andy Grove taught me. I would be more impressed if he was an aerospace guy. Or a highway engineer.
He needs 2 million panels per sq mi. at 1E6 hrs MTBF per panel (under the most daunting environmental challenges - hard pounding in wind, rain, snow, ice, and sun) he will have two panels failing every hour. Forty eight a day. About 350 a week. They better be easy to replace.
This probably deserves some research. It is a long, long, way from prime time.
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Edited to fix math error.
Last edited by MSimon on Sat Aug 29, 2009 5:28 am, edited 1 time in total.
Engineering is the art of making what you want from what you can get at a profit.
You know. I'm an engineer. And even as a preliminary calculation in order to ask for funding for a more in depth look this is a joke. And he shows a level of precision in his numbers not justified by the accuracy of his estimates. It is not only wrong - it clutters the text and makes it hard to read.Professor Science wrote:Costs? Well, they're trying to engineer for something with 3 times the life span of regular asphalt so they're aloquating 3 times the construction cost of regular road to get road +, and since it accomplishes all of the features of road and + for what they claim is the same cost, one could argue the + would come off as an a free ancillary, but I'm sure your using a different method for $ calculation.
I'm more interested in methods as opposed to costs at this point myself. Their website goes in pretty deep depth though, so if you want to go rooting yourself, be my guest. It's latish here and I had a tiring day of lectures and lab. I'm off to bed.
Amateur hour.
BUT OK. I'd like to know where he is getting his unobtanium to cover his panels and withstand a truck pounding. Let us not worry about the Interstate. How about 15 mph parking lots?
And BTW what does the % of possible cars in the lot do to power out? Or road loading.
As I said. I would have more faith in the guy's plans if he was a plastics engineer or a mall engineer or a road engineer.
What he is doing is not a job for an electrical engineer. It is a job for a mechanical engineer. An automobile bridge designer. The electrical design is relatively trivial compared to the mechanical design problems.
Engineering is the art of making what you want from what you can get at a profit.
I've heard that suggested as a genuine suggestion in many places. How stupid! Harvested from what - the extra fuel the cars need to burn to press forward on such a road!!??Betruger wrote:How about piezoelectrics in the roads to harvest energy from cars driving over them?
What could work is speed bumps (if 'strictly' necessary - and that's never the case I can see!) sucking up some of the energy. In fact it may be a good idea as the bump would have to be more compliant to soak up the energy and therefore would be less 'bump' and more 'deceleration'.
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Professor Science
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As a pure power generation method, yes, i agree it is not a great idea, but I'm more interested in retooling the power and information network that these things would represent. Aren't we always talking about how the power grid format right now is not well built for a more distributed network that would come from either renewables or scores upon scores of small 100 megawatt plants? And it would provide an opportunity to unify the grid from 3 disparate systems into one unified one.
That's why even though I don't think it's cost effective as Road + power source, it might be cost effective as road+power source+transmission+data network+cleaning services.
That's why even though I don't think it's cost effective as Road + power source, it might be cost effective as road+power source+transmission+data network+cleaning services.
The pursuit of knowledge is in the best of interest of all mankind.
I don't know the numbers, but does the projected energy aviability consider that the road surface is static and that it cannot tract the Sun, thus decreasing the yield throughout the day? The detrimental effects of North facing slops, trees, etc?. Perhaps building roofs over the roads with potovolaics would be less challenging from a survivability/cost/ maintainance stand point. And the only way I could see that as being pratical is if the cost of electricity is much higher, and the cost of realestate is the dominate factor. Using the right of way associated with wide highways (Interstates) for photovotaic farms seems marginally more pratical. The placing of photovoltics on building rooftops to the extent practical seems much more cost effective (as part of a mix of electricity sources) and even this has not been done to any significant extent. Perhaps when/if the photovotaic vs electricity costs reach parity such schemes will move forward.
Dan Tibbets
Dan Tibbets
To error is human... and I'm very human.
That's right - same roads but with piezo in em. You don't need to make the roads stupidly more resistant than now, given how much road is available.chrismb wrote:I've heard that suggested as a genuine suggestion in many places. How stupid!Betruger wrote:How about piezoelectrics in the roads to harvest energy from cars driving over them?
And with a few milliwatts per sq meter on average this is going to pay off how?Betruger wrote:That's right - same roads but with piezo in em. You don't need to make the roads stupidly more resistant than now, given how much road is available.chrismb wrote:I've heard that suggested as a genuine suggestion in many places. How stupid!Betruger wrote:How about piezoelectrics in the roads to harvest energy from cars driving over them?
It is worse than solar. By at least a factor of 1,000.
Engineering is the art of making what you want from what you can get at a profit.
Damage From Road Trucks
Just a couple of other engineering or environmental problems
Polygirl
P.S. Years and years ago I could not spell engineer, Now I R one.
- Damage to pavement material is dominated by fatigue arising from the peak cycles of longitudinal stress at the bottom to the "pavement" (Rigid or Flexible) under the center of the path traveled by the tires of a truck. Is this material going to be as good under compression and tension?
- How about the damage caused by the wheels of the truck when they encroach on the edges of the "pavement" (Rigid or Flexible) or even the joints?
- Resources consumed in making the panels.
- What about at night when the sun is not shinning.
- How about storage for the excess power generated, how is it going to be stored.
- How about accidents (what about hazard spillage into the the panels) and the effects on the panels.
- How about maintenance?
Polygirl
P.S. Years and years ago I could not spell engineer, Now I R one.
The more I know, the less I know.
A lot of people here have made some very good points and have raised a lot of important questions.
Seeing the condition of the roads in the US, I doubt that they will be able to maintain pavement like that at a level that would be required. Heck even here we have roads that resemble more patchwork than anything else. Roads often have to be dug up to fix pipes, sewers or power lines that are underneath. Then these things quickly get expensive (though it might give our lazy ass politicians some incentive to plan such maintenance better to keep this to a minimum.
Seeing the condition of the roads in the US, I doubt that they will be able to maintain pavement like that at a level that would be required. Heck even here we have roads that resemble more patchwork than anything else. Roads often have to be dug up to fix pipes, sewers or power lines that are underneath. Then these things quickly get expensive (though it might give our lazy ass politicians some incentive to plan such maintenance better to keep this to a minimum.