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logicmanPatrick

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Re: Solar Roadways
« Reply #150 on: September 21, 2017, 04:47:47 AM »
Solar roadways are most effective when not used as roadways.

The hexagons have about 50% active solar panel area.

Traffic, whether pedestrian, cyclist or vehicular throws shadows.

Shadows have greater area the further North or South from the equator.

Shadows consist of umbra and penumbra, so the shadow area is always greater than the geometrically projected area of the object casting the shadow.

Any single cell in a series which is shadowed acts as a resistance to all the other cells, rather like an aged battery in series with new ones.

Road panels are laid flat.  The further from the equator the lower the efficiency.


A better design: An open-sided shelter.

Solar panels should be placed above the road, forming a roof.
The side towards the prevailing wind should consist of open mesh or louvres.  The other side is best left open.

The panels are fixed, oriented to about 12 local time and midway between local max and min zenith angle.  This makes for a simple design with no need for motors to move the panels.

The open mesh or louvred side will actively reduce the impact of wind, rain or snow on road users.

The streetview image linked below shows how the Swale crossing and the louvres keep rain off the ground to such an extent that the soil is bare of plants.

Swale crossing

I am currently installing solar panels in my garden to power my fridge.  I can confirm by direct experiment that if a part of a panel is in shadow, then the whole panel acts as if in shadow: the power drop is significant.
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Rob Dekker

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Re: Solar Roadways
« Reply #151 on: September 21, 2017, 08:49:16 AM »
Regarding solar roadways, I am completely with Dave @ EEVblog, and with several  posters here.

Here is another debunking by Dave on the French system, which uses some sort of polymer PV system that they get to glue to the road :


Even though this concept the cheapest solution out there, it is still 3X the cost of properly installed PV panels, at half the production. A 6X cost disadvantage. To use Dave's words : "It's just completely impractical !".

In general, from an engineering point of view, if you have X dollars to burn on a solar system, as long as you don't live at the equator, you don't put it flat on the ground, you tilt it towards the sun ! Gives a 1/cos(lat) improvement.

And even if you really want to put it flat on the ground, don't let anything drive over it !
You need all kind of enforcements to let vehicles drive over you panels, which pumps up the cost tremendously. At least put these solar panels between freeway lanes or next to railroad tracks or ANYWHERE where you have a bit of free space.

Putting them in a place where vehicles drive over them is just insane.

And regarding putting a 'snow-melt' system in the road, or some LEDs, that is just a completely separate system that has nothing to do with your solar cells in the road. After all, the LEDs are only useful at night and the snow-melting system would switch on when the road is covered in snow. Either way, you will NOT have solar power when these systems switch on.
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Sigmetnow

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Re: Solar Roadways
« Reply #152 on: October 06, 2017, 03:15:30 AM »
Those of you who "don't get it," please remain calm.  See what happens.

Solar Roadways posted on their Facebook page:
Quote
Exciting News: We were in Austria last week, meeting with an interested manufacturing partner there called Blue Sky Energy:
http://www.bluesky-energy.eu/?lang=en.

They currently manufacture environmentally safe saltwater batteries which would pair nicely with SR.

They have a huge, fantastic, open factory as you can see in the photos and they are interested in beginning the manufacturing of Solar Roadways panels there for the European market. We are now in talks with them regarding the details. If you are interested in getting involved in this European endeavor, feel free to email us for more info or request a personal introduction to Blue Sky Energy...
...
It’s time to get full production going around the world so we can begin to say “Yes” to the interested customers who reach out to us from all over the world every week.
https://www.facebook.com/solarroadways/posts/10154633700377126
Photos at the link.

Solar Roadways commented:  "Thank you Kaye Clark, we are blessed to have tons of interest from all 50 states. We are also in talks re manufacturing in Ohio and once we get going, we'll need manufacturing in just about every state. :) "
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crandles

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Re: Solar Roadways
« Reply #153 on: October 06, 2017, 11:14:32 AM »
Replies to every comment it seems. Almost as if they are more interested in getting an internet presence/following than getting on with doing things?? Or is that too harsh?

Sigmetnow

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Re: Solar Roadways
« Reply #154 on: October 06, 2017, 08:06:46 PM »
Replies to every comment it seems. Almost as if they are more interested in getting an internet presence/following than getting on with doing things?? Or is that too harsh?

They've done that since the beginning.  It's a little unusual, but they are always very polite, and I think they genuinely appreciate positive comments, given all the flack they also receive!  They don't sponsor or pay for ads, so only people who follow them (or look them up) will see the comments.  No doubt they feel they should use any opportunity to correct misinformation they come across, and spread positive news.
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Sigmetnow

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Re: Solar Roadways
« Reply #155 on: December 02, 2017, 04:43:14 AM »
Solar Roadways is partnering with an Ohio company to manufacture their panels, which will soon be available for purchase.

Quote
Happy News: We have agreed on terms with our Ohio manufacturing partner, E-Mek Technologies, and the final contract is scheduled to be completed in December. The team pictured was at our headquarters in Sandpoint, Idaho yesterday to wrap up our agreement.

They will begin manufacturing panels in the new year. Jobs will be created in Ohio and a couple of new jobs in Idaho (Software, Firmware, Hardware Engineers) as well. Panels will soon be available for purchase. Many distributors will be needed all over, beginning in the Ohio area. Ideal distributors are those who already have a network in place, such as General Contractors, Rooftop Solar Companies, Real Estate Developers, Landscape Contractors, etc. Watch for news about trainings for distributors and installers.

We hope you will take the time to “like” and comment on their new Facebook page: https://www.facebook.com/emektech/

You can also learn more about them on their website: https://www.e-mek.com/

If you would like to be personally notified when panels are close to becoming available:
Customers@SolarRoadways.com

If you are interested in jobs in Ohio, or becoming a certified Solar Roadways distributor:
Careers@SolarRoadways.com
Distributors@SolarRoadways.com

We are happy to make personal introductions to the team at E-Mek.
https://www.facebook.com/solarroadways/posts/10154760212307126
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Sigmetnow

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Re: Solar Roadways
« Reply #156 on: December 15, 2017, 10:12:46 PM »
Installation soon in Baltimore, Maryland: the Inner Harbor Visitor’s Center.  Temporary display; indoors. Larger permanent display to be installed outdoors later this spring.

Quote
Baltimore Area Supporters: Scott and our team member Alyssa will be in Baltimore next week installing a 6–panel display inside the beautiful Visitor’s Center at the Inner Harbor (seen behind us in this photo). There will be a larger permanent display installed at the Inner Harbor in the spring. The Sandpoint pilot installation of SR3s is doing its job of bringing forth glitches and areas to upgrade. Scott is already in the midst of designing SR4, so we decided to wait and install SR4s for Baltimore. The temporary display using SR3 panels will give east coast supporters a place to go to see the panels in the meantime.

There will be a press conference at the Visitor’s Center at 2:00 p.m. on December 18th and you all are invited to come by, see the panels and meet Scott and Alyssa. Mark Dixon of YERT will be there filming. Solar Roadways is included in their film (http://www.yert.com/film.php) about solutions to Climate Change and they are now working on a full length documentary about Solar Roadways (http://www.solarroadwaysfilm.com/). Visitors on the 18th may have an opportunity to be included in the film if desired.

Watch for lots of pics on our Instagram account: https://www.instagram.com/official_solar_roadways/
...
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oren

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Re: Solar Roadways
« Reply #157 on: December 16, 2017, 10:44:21 AM »
3 months after my previous post here I allow myself to post again, still calling BS. Every one of their press releases screams it's a prolonged scam with a poorly conceived idea behind it, something from a science fair project rather than a business or real solution.
"Panels will soon be available for purchase" - not even giving a target date. Moving as slow as possible on purpose, of course not afraid of any competition.
"Many distributors will be needed all over, beginning in the Ohio area" - even the language is funny. And why is the manufacturing location relevant to where the distributors will be needed?
"Ideal distributors are those who already have a network in place, such as General Contractors, Rooftop Solar Companies, Real Estate Developers, Landscape Contractors, etc."  - who are the potential customers? I thought roadways belong to public entities, and the distributors are anything but the list shown here. Supposedly they should begin by a large proof-of-concept deployment with some city government.
"in Baltimore next week installing a 6–panel display inside the beautiful Visitor’s Center at the Inner Harbor (seen behind us in this photo). There will be a larger permanent display installed at the Inner Harbor in the spring." - indoors display, almost a joke. And a snail's pace of doing anything.

Apologies in advance for the rant, and see you again in 3 months...

Bob Wallace

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Re: Solar Roadways
« Reply #158 on: December 16, 2017, 05:09:21 PM »
I think the real tell here is that no big money has gotten involved by either funding expansion or buying out the idea and expanding it.

Sigmetnow

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Re: Solar Roadways
« Reply #159 on: December 16, 2017, 06:02:47 PM »
A.  They are still developing and improving the product — version 4 is mentioned above.  Rome was not paved in a day!  ;D

B.  They have mentioned partners, like the Ohio manufacturing company posted above.  And that they have projects with others whom they are not allowed to publicise yet.

See you in three months! ;)
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TerryM

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Re: Solar Roadways
« Reply #160 on: December 16, 2017, 08:06:42 PM »
3 months after my previous post here I allow myself to post again, still calling BS. Every one of their press releases screams it's a prolonged scam with a poorly conceived idea behind it, something from a science fair project rather than a business or real solution.
"Panels will soon be available for purchase" - not even giving a target date. Moving as slow as possible on purpose, of course not afraid of any competition.
"Many distributors will be needed all over, beginning in the Ohio area" - even the language is funny. And why is the manufacturing location relevant to where the distributors will be needed?
"Ideal distributors are those who already have a network in place, such as General Contractors, Rooftop Solar Companies, Real Estate Developers, Landscape Contractors, etc."  - who are the potential customers? I thought roadways belong to public entities, and the distributors are anything but the list shown here. Supposedly they should begin by a large proof-of-concept deployment with some city government.
"in Baltimore next week installing a 6–panel display inside the beautiful Visitor’s Center at the Inner Harbor (seen behind us in this photo). There will be a larger permanent display installed at the Inner Harbor in the spring." - indoors display, almost a joke. And a snail's pace of doing anything.

Apologies in advance for the rant, and see you again in 3 months...


Wasn't aware that three months had passed already.


If I offer a parking lot with a solar shade roof, and you offer a parking lot with solar paving. My parking lot will be producing energy whenever the sun shines & your parking lot will only produce when people have left your lot to park in the shade at my lot. 8)


Solar paving is a wonderful solution to a nonexistent problem.
Terry

ghoti

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Re: Solar Roadways
« Reply #161 on: December 16, 2017, 09:00:07 PM »
Quote
Solar paving is a wonderful solution to a nonexistent problem.
Terry
So true but the solar paving idea was an almost direct result of the deniosphere spreading false concerns like "where would we put all the PV panels needed?" The innocent response was we'll just cover all the wasted space we call roads with PV to solve that problem.

The solution has kind of wandered off the initial reasoning and you might expect since it never was a need.

Bob Wallace

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Re: Solar Roadways
« Reply #162 on: December 16, 2017, 09:30:29 PM »
Quote
The innocent response was we'll just cover all the wasted space we call roads with PV to solve that problem.

I recall those discussions well before the idea on putting panels on the rod surface appeared. 

The answer was to build canopies over roads, especially in places with hot summers were cars get caught up in stop and go traffic.  Use the space that is not being used for anything else.  Provide shade for traffic and lower AC needs.

There's an interesting solar railway in Europe.  The tracks run through a protected forest which means that the trees cannot be cut.  Tree limbs break off from time to time and end up on the track, which can be dangerous.

The solution was to build a protective canopy over the track and as long as they were building the 'roof' putting solar panels help power the train made sense.

Sigmetnow

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Re: Solar Roadways
« Reply #163 on: December 17, 2017, 03:03:53 AM »
Most of the arguments against Solar Roadways here seem to concentrate on the idea that road surfaces are not the best locations for solar panels.  That’s like saying that EVs make no sense because they can’t go 800 miles on a single charge.

The SR panels have the potential to do so much more than just generate solar power. Examples: Road flood control by diverting rainwater; burying utility cables underground; melting road/driveway/sidewalk/parking lot snow and ice; improved surface traction in slippery locations; interactive traffic warnings and markings; even new kinds of playground games.  There are many other uses for the product — perfect solar generation is not the primary goal.
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TerryM

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Re: Solar Roadways
« Reply #164 on: December 17, 2017, 11:15:20 AM »
Isn't the above similar to arguing that we need concrete roads, or we can't have bridges?


All but the last two of your "examples" are incorporated into the paved areas of my 2+Decade old high rise.


It's nice to have the snow and ice melted, then flushed away through the storm drains, but if they wanted to go green with it, I'd recommend solar shade for comfort during the summer months.
Terry

Sigmetnow

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Re: Solar Roadways
« Reply #165 on: December 17, 2017, 03:00:21 PM »
Isn't the above similar to arguing that we need concrete roads, or we can't have bridges?


All but the last two of your "examples" are incorporated into the paved areas of my 2+Decade old high rise.


It's nice to have the snow and ice melted, then flushed away through the storm drains, but if they wanted to go green with it, I'd recommend solar shade for comfort during the summer months.
Terry

Solar Roadways are not made of cement or petroleum products.  So there’s that.
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Bob Wallace

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Re: Solar Roadways
« Reply #166 on: December 17, 2017, 05:01:41 PM »
The panels sit on a concrete base.  A concrete road that has to be strong enough to handle "oversize" commercial loads.

Sigmetnow

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Re: Solar Roadways
« Reply #167 on: December 17, 2017, 05:17:52 PM »
The panels sit on a concrete base.  A concrete road that has to be strong enough to handle "oversize" commercial loads.

Point taken!  But at least it won’t have to be continually “re-surfaced” in concrete.

Edit:  And the heaviest base won’t be needed for sidewalks, driveways, playgrounds, most secondary roads, etc.

Another edit:  Since the panels distribute weight over a larger area than where a tire touches the road, it may be that a less rigorous base would be needed....
« Last Edit: December 17, 2017, 06:10:24 PM by Sigmetnow »
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Bob Wallace

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Re: Solar Roadways
« Reply #168 on: December 17, 2017, 06:29:24 PM »
The two things that cause solar panels to lose output faster are high UV levels and flexing/loading.  Panels degrade fastest where there's a lot of wind or snow loading.  Traffic passing over means loading.

I don't live where there's lots of snow and salting.  Here in CA I don't see concrete surfaces needing much repair.

I doubt a sheet of glass would spread the force over a much higher area.

I'm waiting for some proof that there is a glass that will continue to transmit light as it gets a good surface grinding from heavy vehicles running over gravel and sand.  But I've gone down my list of why I'm skeptical before.


Sigmetnow

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Re: Solar Roadways
« Reply #169 on: December 20, 2017, 02:03:59 AM »
Brief article and video from the Baltimore event.  The Abell Foundation liked the idea enough to donate $100,000 for the sidewalk project.

Baltimore’s Inner Harbor Testing Out Solar Sidewalk
http://baltimore.cbslocal.com/2017/12/18/solar-sidewalk/
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Rob Dekker

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Re: Solar Roadways
« Reply #170 on: December 20, 2017, 04:10:42 AM »
Most of the arguments against Solar Roadways here seem to concentrate on the idea that road surfaces are not the best locations for solar panels.

No Sigmetnow. It's not just "not the best location", it is the WORST POSSIBLE location to put solar panels (short of putting them indoors).

Didn't you see the engineering analysis in the Dave @ EEVblog video I posted above ?
There is a 6X cost disadvantage right off the bat, and that is just for starters.

It means that you can generate 6X the energy for the same amount of dollars invested by putting these solar panels ANYWHERE ELSE but in roads.

As for your other arguments :
Quote
Road flood control by diverting rainwater; burying utility cables underground; melting road/driveway/sidewalk/parking lot snow and ice; improved surface traction in slippery locations; interactive traffic warnings and markings; even new kinds of playground games.
You can have all these gadgets in a road surface if you like.
But then it would STILL make no cost sense to put solar panels in such a fancy road.

If we are to create a future where energy is mostly generated by solar/wind and other renewables, we should NOT start by putting ourselves at a 6X cost disadvantage. Since if we do, we will NEVER get there.
« Last Edit: December 20, 2017, 05:09:03 AM by Rob Dekker »
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Sigmetnow

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Re: Solar Roadways
« Reply #171 on: December 20, 2017, 04:44:06 PM »
Rob,
What if new technology makes solar roadways panels six times better for the environment than paved surfaces?  Wouldn’t that be worth extra monetary cost?  Particularly as we come to accept that carbon emissions must be reduced much more rapidly than we imagine can be done today.

There’s all that pizo-electric potential of vehicles passing over the road, for starters....

There are many ways to “prove” solar roadways “won’t work” today.  Just like they did with electric vehicles and re-usable rockets.  I choose to encourage the SR folks to try, and to learn.  Their next big improvement might be as equally groundbreaking.
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Rob Dekker

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Re: Solar Roadways
« Reply #172 on: December 21, 2017, 05:39:37 AM »
What if new technology makes solar roadways panels six times better for the environment than paved surfaces? 
Not sure what kind of technology you are talking about, especially since solar roadways are 6X WORSE for the environment than putting solar panels elsewhere. No matter which solar technology you use !

Quote
Particularly as we come to accept that carbon emissions must be reduced much more rapidly than we imagine can be done today.
For the same amount of dollars invested, you obtain 6X the energy by NOT putting these solar panels in a road. So solar roads will just slow down transition to lower emissions, by a factor of 6 !

Quote
There’s all that pizo-electric potential of vehicles passing over the road, for starters....
Piezo-electric elements in the road would increase drag on vehicles. It would just transfer energy from the vehicle to the piezo-electric elements. At bad efficiency too.
There is no free lunch when it comes to energy, and piezo-electrics are no exception.

Quote
There are many ways to “prove” solar roadways “won’t work” today.  Just like they did with electric vehicles and re-usable rockets.  I choose to encourage the SR folks to try, and to learn.  Their next big improvement might be as equally groundbreaking.

Please watch Dave's video, Sigmetnow. The factor 6 is not going to change with improved technology. It is INHERENT to putting solar panels in the worst possible spot (in a road).
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Sigmetnow

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Re: Solar Roadways
« Reply #173 on: December 21, 2017, 02:35:16 PM »
Rob,

You are fixating on the solar aspect, without regard to the other benefits.  So what if solar on the ground is less than optimal?  That doesn’t matter!  The point is that solar can be integrated into a new technology that may open up entirely new possibilities.

The big Tesla battery in Australia can only supply a few hours of power for a few thousand homes.  Ho-hum.  But its ability to supply ten minutes of grid frequency stabilization within microseconds of a loss can help keep the entire grid from going down. 

There is more going on here than many people imagine.  As Elon Musk said when everyone “proved” an electric car company could not succeed: “I don’t care.  We’re going to do it anyway.”  And the world has changed because of it.
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Sigmetnow

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Re: Solar Roadways
« Reply #174 on: December 21, 2017, 09:58:06 PM »
China is building solar roadways – ‘transparent concrete’ atop solar cells that charge driving cars
Quote
China is building roadways with solar panels underneath that may soon have the ability to charge cars wirelessly and digitally assist automated vehicles. This second solar roadway project – part of the Jinan City Expressway – is a 1.2 mile stretch. The building technique involves transparent concrete over a layer of solar panels.

Construction is complete and grid connection is pending, but is expected to be complete before the end of the year.

 The Jinan City solar highway is formed with three layers. The top layer is a transparent concrete that has similar structural properties with standard asphalt. The central layer is the solar panels – which are pointed out as being ‘weight bearing.’ The bottom layer is to separate the solar panels from the damp earth underneath. The road will be durable enough to handle vehicles as large as a medium sized truck.

It was noted by engineers that wireless vehicle charging could soon be integrated and automated car functions could take advantage of the inherent data in this this already wired roadway.
...
Last September the Quilu Transportation Development Group completed the first solar roadway in the same city of Jinan. This is the same  state owned company that built the first one. The first project took 10 months to complete and is fitted with 790 square yards of solar panels. ...
Even though Solar Roadways have their critics, they are being tested in multiple locations around the world....

Quote
Everyone that made fun of solar roadways (I don’t know of any serious engineers that gave positive feedback on the idea) might end up with egg on their face. How many of these groups considered that solar panels might be below 20¢/W? How many of these people considered that clear concrete would be a viable thing? China has the solar chops to take on real research and experiment with things that might fail – I no longer doubt solar roadways might work.
https://electrek.co/2017/12/21/china-solar-roadways-transparent-concrete-solar-cells-charge-cars/
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Bob Wallace

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Re: Solar Roadways
« Reply #175 on: December 21, 2017, 11:33:53 PM »
Panels only.  None of the LED and ice melting stuff.

Panels mounted under "clear concrete".  Traffic won't be driving on the panel cover glass.

" durable enough to handle vehicles as large as a medium sized truck"

Not useful for US roads.  We use big trucks and need to move heavy equipment even in rural and suburban areas.

"The first project took 10 months to complete and is fitted with 790 square yards of solar panels. "

7110 square feet.   1 kW = 5.89 m^2 = 64 sq ft with 17% efficient panels. 

111 kW of panels.  That would take only a few days to install in a typical solar farm.  And the panels would track the Sun and not get covered by vehicles and road filth.






TerryM

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Re: Solar Roadways
« Reply #176 on: December 22, 2017, 01:25:35 AM »
Ouch
Don't want to pile on, but we're talking about two different projects here and I think some of the information might be getting mixed.


#1 - http://english.ningbo.gov.cn/art/2017/10/14/art_926_847292.html


A "photovoltaic road pilot zone" that is 160 meters long and covers a total of 660 meters.
It was launched last December and completed on September 29.
It's claimed that it can "heat the surface, helping to keep it free from snow and ice."


#2 - https://electrek.co/2017/12/21/china-solar-roadways-transparent-concrete-solar-cells-charge-cars/


A "3 layer roadway being built as part of the Jinan City Expressway" this section is 1.2 Miles long.
It is expected to be completed before the end of this year, and tied to the grid at that time.
Two sizes of solar panel are being used.


Both are claimed to be able to carry "medium sized trucks."
No electrical specs are available for either project.
Both project are in the city of Jinan and involve the same state owned construction company.


In one location the total area of the 1st project is given as 660 sq meters. In another location, within the article about the 2nd project the 1st project is claimed to have 790 sq yards of solar panels. Someone is in error since 790 sq yds is ever so slightly larger than 660 sq meters.


The top layer is claimed to be a "transparent concrete that has similar structural properties with standard asphalt" - and that's some trick since asphalt is nothing like concrete and is formulated for the specific conditions it is expected to face.


I stand by all of my previous arguments, and add that this won't stand up to normal truck use.
Sorry
Terry






Rob Dekker

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Re: Solar Roadways
« Reply #177 on: December 22, 2017, 05:32:07 AM »
It's unfortunate that there are no cost numbers given for the Chinese projects.
In the link that Sigmetnow gave I do see some hard numbers for the French project :

Quote
France soon followed suit by building a solar roadway of their own. The project is in the Normandy village of Tourouvre-au-Perche. The 1 km (0.6 mile) long solar road installation consists of 2,800 sq m (30,139 sq ft) of energy-producing panels. The system cost about 5m,

OK. Let's do the match :
2800 m^2 using 17% efficient panels with 1000 W/m^2 peak solar power gives 476000 W peak electric. At 5 Million (euro?) that is 10 EURO per watt peak.
Installed roof solar goes for about 2-3 EURO per watt peak. That's a factor 3 to 5 in cost right there.

Now from Dave's engineering analysis we know that the solar road in the Netherlands produces about half the power that nearby rooftop solar produces.

So we are looking at a 6X to 10X cost disadvantage w.r.t. rooftop solar. As Dave would say : "It's ridiculous !"

[edit] If the French would have mounted these panels NEXT TO the road, on a commercial mounting system, they could do this for the price of rooftop solar or less, and with tilted mounting they would obtain another factor 2. So for the same amount of money invested they could have obtained 6-10X the production compared to putting the solar panels IN the road.

And as a bonus maintenance and repair would be a LOT easier.
« Last Edit: December 22, 2017, 06:00:51 AM by Rob Dekker »
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Re: Solar Roadways
« Reply #178 on: December 22, 2017, 05:49:47 AM »
Quote
Installed roof solar goes for about 2-3 EURO per watt peak. That's a factor 3 to 5 in cost right there.

Installed single-axis tracking solar in the US is now $1.08/watt. 

By putting panels flat rather than angled at a constant angle (best for year round) you lose about 13% of output.  (I looked it up for Manhattan, Kansas.)

A fixed mount panel would have a CF of 18%.  With tracking it moves close to 30%.

" 10 EURO per watt peak" vs. about 1 Euro per watt peak.  Plus at least 50% more output and a longer solar day.  15x more expensive even before you discount for dirt and traffic.
--

I really am interested in learning more about the Chinese transparent concrete. 


Rob Dekker

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Re: Solar Roadways
« Reply #179 on: December 22, 2017, 06:22:59 AM »
Quote
Installed roof solar goes for about 2-3 EURO per watt peak. That's a factor 3 to 5 in cost right there.

Installed single-axis tracking solar in the US is now $1.08/watt. 

I compared it to rooftop solar.
If we take your number than the cost disadvantage of putting these panels in a road is more like 20X. Is there any more explicit expression than Dave's "ridiculous" ?

Quote
By putting panels flat rather than angled at a constant angle (best for year round) you lose about 13% of output.  (I looked it up for Manhattan, Kansas.)

Mmm. I always thought the loss of not tilting is 1/(cos(lat)) which would be 45 % for France and 62 % for the Netherlands.
I guess the remainder of the 2X production loss that Dave pointed out is due to dirt on the road and more losses due the the not so "transparent" top layer.

Quote
I really am interested in learning more about the Chinese transparent concrete.

Me too.
« Last Edit: December 22, 2017, 07:02:05 AM by Rob Dekker »
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Re: Solar Roadways
« Reply #180 on: December 22, 2017, 08:45:21 AM »
Quote
I always thought the loss of not tilting is 1/(cos(lat)) which would be 45 % for France and 62 % for the Netherlands.

I worked off this page -

http://solarelectricityhandbook.com/solar-irradiance.html

Averaged the monthly numbers for flat and optimal year round tilt.  The differences were smaller than I thought  the would be.  (Or I could have made a mistake.)

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Re: Solar Roadways
« Reply #181 on: December 22, 2017, 04:46:10 PM »
If the French would have mounted these panels NEXT TO the road, on a commercial mounting system, they could do this for the price of rooftop solar or less, and with tilted mounting they would obtain another factor 2. So for the same amount of money invested they could have obtained 6-10X the production compared to putting the solar panels IN the road.

And as a bonus maintenance and repair would be a LOT easier.

In locations with seasonal snow, I'd think there could be particular advantages to constructing these as solar canopies over roadways.  Angled panels would generate more power, while allowing snow to slide off, perhaps with a tiny bit of power to warm the panels.  Keeping snow off the roadways would make snowplowing a matter of touch-up for un-covered segments of road.  More generation per meter-squared, less rain and snow on the roads, cooler cars in the summer (needing less A/C) and generation right next to, perhaps, charging roadways.  And close to zero extra land use.

An occasional car will drive off the road and hit support structures, but clever engineering should be able to prevent serious damage to car or canopy. 

Bob Wallace

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Re: Solar Roadways
« Reply #182 on: December 22, 2017, 06:15:03 PM »
Quote
clever engineering should be able to prevent serious damage to car or canopy

Plastic tanks filled with compressible material.  Big cushions. 

There are many approaches to absorbing the energy in impacts or deflecting the main force of the impact.

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

Plus design the supports so that supports can detach from the array if they are struck.  The array might sag a bit but not come down with the loss of a single support.

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Re: Solar Roadways
« Reply #183 on: December 23, 2017, 01:54:42 AM »
Quote
I always thought the loss of not tilting is 1/(cos(lat)) which would be 45 % for France and 62 % for the Netherlands.

I worked off this page -

http://solarelectricityhandbook.com/solar-irradiance.html

Averaged the monthly numbers for flat and optimal year round tilt.  The differences were smaller than I thought  the would be.  (Or I could have made a mistake.)

Bob, you did not make a mistake. I did. My 'cos(lat)' tilting factor for production is only valid at noon. In the morning and afternoon tilt matters less, and so I need to revise my formula.
Meanwhile your solarelectricityhandbook.com provides the right answers.
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Sigmetnow

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Re: Solar Roadways
« Reply #184 on: December 23, 2017, 03:26:19 PM »
...
So we are looking at a 6X to 10X cost disadvantage w.r.t. rooftop solar. As Dave would say : "It's ridiculous !"

[edit] If the French would have mounted these panels NEXT TO the road, on a commercial mounting system, they could do this for the price of rooftop solar or less, and with tilted mounting they would obtain another factor 2. So for the same amount of money invested they could have obtained 6-10X the production compared to putting the solar panels IN the road.

And as a bonus maintenance and repair would be a LOT easier.

Too bad batteries are soooo expensive — electric vehicles would be such a great idea!  Guess we can’t make them, though, because they’d be much more expensive than ICE cars....

Edit:  and the battery would cost 10,000 times more than a gas tank!  ;)

Do you really think they didn’t consider the alternatives?  And test out the components with a small-scale project to verify the solar generation would be sufficient for their needs and economic viability?


“And as a bonus maintenance and repair would be a LOT easier.”

LOL.  If only the surface was constructed of some sort of (hexagonal) sturdy panels that communicated with each other, reported malfunctions, and could be replaced in a minute by two guys in a pickup truck lifting out the bad panel and dropping in new one.  Like the Brusaw’s Solar Roadway. ;D
« Last Edit: December 23, 2017, 06:28:03 PM by Sigmetnow »
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Re: Solar Roadways
« Reply #185 on: December 23, 2017, 05:47:08 PM »
Quote
Too bad batteries are soooo expensive — electric vehicles would be such a great idea!  Guess we can’t make them, though, because they’d be much more expensive than ICE cars....

Feels to me as if you've gotten yourself so firmly in the solar roadway corner that you're not being your normal objective self. 

The similar comparison to putting solar panels 'above roads' and 'inside roads' is not EV/ICEV but EV/H2 FCEV.  We have to quit ICEVs because we must cut our carbon output.  Both EVs and H2 FCEVs give us low carbon transportation but one is significantly less expensive.

The solar roadway is a combination of functions.  Let's break them out....

1) Generate electricity.  Much less expensive per MWh to put the panels in a solar farm.

2) Provide signage.  Overhead signs are much easier to see than signs in the road where they will often be blocked by traffic/dirt/snow.  And you'll have to get right up to the in-road sign to read where the LED signs we use now can be read from a mile back or so.

3) Supposed long term low slippage surface.  A layer of glass over concrete.  OK, let's pull out that one function and give it a try.  How well will that glass surface hold up compared to a non-covered concrete road.

4) Ice and snow melting.  This has been tried and it simply takes too much energy to be practical.

Sigmetnow

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Re: Solar Roadways
« Reply #186 on: December 23, 2017, 06:55:23 PM »

The solar roadway is a combination of functions.  Let's break them out....

1) Generate electricity.  Much less expensive per MWh to put the panels in a solar farm.

It would be much less expensive to power cell phones with a wall charger instead than small batteries, which can be inefficient and even burst into flames if they are not made well.  But that rather obviates the idea of a mobile phone.  Despite the name, major amounts of solar power is not necessarily the overarching goal of a solar roadway.  And simple or less expensive is not necessarily the best solution.  Nobody’s saying get rid of solar farms and put in a road.  But let’s see if we can design a “smart” road that generates income without using tolls, and generates more electricity than it uses.


Quote

2) Provide signage.  Overhead signs are much easier to see than signs in the road where they will often be blocked by traffic/dirt/snow.  And you'll have to get right up to the in-road sign to read where the LED signs we use now can be read from a mile back or so. 

You cannot move overhead signs to where they are needed, or install them where they will be blocked by trees, bridges, or topography.  Would you want an overhead sign planted on your front yard?  A long solar road can give warnings in several places, well before the hazard.  Can update automatically, immediately indicating lanes that should be slowed or evacuated, or that are now clear.


Quote

3) Supposed long term low slippage surface.  A layer of glass over concrete.  OK, let's pull out that one function and give it a try.  How well will that glass surface hold up compared to a non-covered concrete road.   

The Brusaws originally used the very toughest, most friction-capable glass they could find.  Highway experts told them to dial it back. :)

Quote

4) Ice and snow melting.  This has been tried and it simply takes too much energy to be practical.

Elon Musk has said his solar roof can melt snow and still be “strongly net positive” for electricity.  Even if a solar road (or driveway, or sidewalk) needs to draw from the grid from time to time, the safety factors, and eliminating the need for poisonous chemical melters, residential or business shoveling, waiting for snowplows, etc. can make it “practical.”  How valuable is human life, less pollution and avoidance of suffering?
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Re: Solar Roadways
« Reply #187 on: December 23, 2017, 07:48:25 PM »
I'm outta here....

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Re: Solar Roadways
« Reply #188 on: December 24, 2017, 04:47:52 AM »
Actually the 400 series highways in Canada are equipped with overhead electric signs that warn of traffic jams ahead, bad road conditions or weather ahead, lane restrictions. or simply remind you to buckle the seatbelt. I'm also a fan of the signs that flash your speed back at you when approaching a lower speed zone.
My guess is that melting snow and ice removal would be a necessity for any solar road design. The snowplows are just too destructive to road surfaces.
In any of the "snow belts" this is going to require vast amounts of electricity, in part because of the need to clear the roads rapidly. In my parking lot snow and ice are melted through the pavement, but the design also allows snow plows to intervene during or after a heavy snowfall.


If solar paving lives up to all of it's hype, but is restrained by the high costs and low energy outputs that many here claim. Where would you find a use for the product?
It can't be used on highways because of the weight concerns so we're restricted to some residential city streets, public parking areas, or private entrances or parking. Which usage would make sense to you?


Terry

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Re: Solar Roadways
« Reply #189 on: December 24, 2017, 10:33:05 AM »
Two years and $ 3.9 million later, this is what happened with these "Solar Roadways" :



The prototype was not actually a 'roadway', but instead a bunch of tiles on a walkway in front of a public restroom (I'm not kidding).

And all this time, they did not produce ANY power at all, the LEDs are invisible in daylight, the tiles are wobbling, many of the tiles failed quickly, and ... their control panel caught fire within weeks of installation.

On the bright side, these tiles DO melt snow simply because they use a LOT of electricity.

Need we say more ?
« Last Edit: December 24, 2017, 10:47:54 AM by Rob Dekker »
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Re: Solar Roadways
« Reply #190 on: December 24, 2017, 10:53:24 AM »
Another good overview of why Solar Roadways is simply NOT working :

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Re: Solar Roadways
« Reply #191 on: December 24, 2017, 11:21:58 AM »
Elon Musk has said his solar roof can melt snow.... 

Where did Elon Musk say that his solar roof can melt snow ?

And why does Elon Musk invest in ANY far out idea EXCEPT for solar roadways ?
Because it is a REALLY BAD idea.
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Re: Solar Roadways
« Reply #192 on: December 24, 2017, 11:46:54 AM »
"Solar glass tiles can also incorporate heating elements, like rear defroster on a car, to clear roof of snow and keep generating energy"

Q: won’t it be energy intensive to melt the snow? Would it be net positive?

"strongly net positive"

https://twitter.com/BobaFaux/status/792220396653117441
28 Oct 2016

'can incorporate' would not seem to mean his personal roof does or even that the tiles his co. sell have that as an option.

On a slope probably only need a little water to lubricate the snow sliding off. On a flat road, it will be much more energy intensive (and slightly less gain due to angle).

He hasn't got enough funds to invest in large numbers of far out ideas so I doubt that argument even if I largely agree with conclusion.

Sigmetnow

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Re: Solar Roadways
« Reply #193 on: December 24, 2017, 03:24:28 PM »
...
My guess is that melting snow and ice removal would be a necessity for any solar road design. The snowplows are just too destructive to road surfaces.
In any of the "snow belts" this is going to require vast amounts of electricity, in part because of the need to clear the roads rapidly. In my parking lot snow and ice are melted through the pavement, but the design also allows snow plows to intervene during or after a heavy snowfall.   

From the SR Research page:
“In northern climates, the heating elements can use up to 2.281MW per lane mile with the heating elements constantly on. Since they only need to be on during the winter months and sporadically even then, it is difficult to calculate the total power required to get through a winter. It would vary greatly from one location to the next and from one winter to the next. The costs of running snow plows and the chemicals used by the plows would offset the cost of the electricity needed to run the heating elements in the Solar Roadway system.”
See: http://www.solarroadways.com/Research/Research   Under “Phase II Research”


Quote
If solar paving lives up to all of it's hype, but is restrained by the high costs and low energy outputs that many here claim. Where would you find a use for the product?
It can't be used on highways because of the weight concerns so we're restricted to some residential city streets, public parking areas, or private entrances or parking. Which usage would make sense to you?

Terry, the glass is more than able to stand up to highway traffic!  From the SR website:

“Glass samples were also sent off too another civil engineering university for load testing and impact resistance testing. The load testing showed that a pavement made of our SR Panels could withstand a static load of 250,000 pounds. To put that in perspective, the national weight limit for semi-trucks is 80,000 pounds. So the test results indicated that SR Panels can withstand more than three times the legal load of fully-loaded semi-trucks. These results were incredible but needed to be reconfirmed, so we were asked to perform a 3D Finite Element Method analysis (computer simulation) at a different civil engineering university. The results came back the same: 250,000 pounds.”

And about the visibility of the LEDs:
“…even on their brightest setting, the LEDs were difficult to see (and more difficult to photograph) in the daylight. We knew it would be a very easy fix for the next prototype, but it was frustrating not to be able to show the parking lot lights in the daytime.“

See: http://www.solarroadways.com/Research/Research   Under “Phase II Research”
They are also testing how the panels fare under braking and acceleration forces, etc. 

I urge everyone to read more about the actual product, rather than guessing!
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Sigmetnow

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Re: Solar Roadways
« Reply #194 on: December 24, 2017, 04:01:56 PM »
Another good overview of why Solar Roadways is simply NOT working :
...

Had to scan through most of this; couldn’t stand listening to his whiny, petulant toddler tone — which by itself reduces any believability to near zero.  As a wise man recently said, “You can prove teleportation exists using Powerpoint [or making a video].”

We covered the Sandpoint installation difficulties upthread.  If all inventors gave up after a failure the way “Dave?” suggests, we’d still be living in caves and using candles!  Learn from mistakes and carry on!

But the best part of the video is a quote showing the SR energy production.  So he admits the solar does work!  The panels just don’t use the power the way “Dave” would like.  Dave is clueless.

People who say it cannot be done should not interrupt those who are doing it.

Sigmetnow

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Re: Solar Roadways
« Reply #195 on: December 24, 2017, 04:10:48 PM »
Here’s what the Department of Transportation is looking for:

Quote
In the original solicitation, eight attributes for a new type of pavement were defined:

1. It generates its own power; either through the energy of the sun or perhaps the energy of the moving vehicle mass traveling over the pavement.

2. It is intelligent enough to transfer the power generated to where it is most needed or to a temporary storage apparatus.

3. It is made of recycled or other sustainable materials.

4. It can be modular for ease of replacing worn or damaged sections.

5. It is durable enough to withstand repeated loading from heavy traffic at or above the level of current pavement systems.

6. It meets or exceeds safety characteristics of existing pavement systems.

7. It mitigates water runoff through either permeability or designed retention and filtration.

8. It is at a cost that allows it to be financially self-sustaining; meaning that the benefits of power generation and water runoff mitigation over the design life outweigh its initial cost.
SR says:
Quote
The combination of the power generation, leasing of the accompanying Cable Corridor to power and data companies, water runoff mitigation, and potential advertising (parking lots) should cover the costs of the system. None of this even takes into account the amount of subsidies available for renewable energy projects.
« Last Edit: December 24, 2017, 05:31:24 PM by Sigmetnow »
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Re: Solar Roadways
« Reply #196 on: December 24, 2017, 06:24:44 PM »
Quote
On a slope probably only need a little water to lubricate the snow sliding off. On a flat road, it will be much more energy intensive (and slightly less gain due to angle).

This is my experience.  Once the panel heats up enough to melt the snow/ice in direct contact with the front glass the snow starts sliding off the panels.  Only a tiny percentage of the snow is melted, it's simply escorted off the premises.

Actually melting all the ice and snow would take very much more energy. 

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Re: Solar Roadways
« Reply #197 on: December 24, 2017, 06:41:18 PM »
I thought I was done with this topic.  Guess not...

Quote
The load testing showed that a pavement made of our SR Panels could withstand a static load of 250,000 pounds. To put that in perspective, the national weight limit for semi-trucks is 80,000 pounds.

No, the test showed that the glass could withstand that load. 

Quote
Glass samples were also sent off

Now, how was the test performed?  A 250,000 pound load spread over what area?  An 80,000 pound truck divides its weight over 18 contact points (bottoms of wheels).  4,444 pounds per wheel.  Work that down to pounds per square inch (PSI).  Was the test 13,889 pounds per wheel footprint?  Was it the same PSI loading or was the load evenly spread over a piece of glass?

To test panels they would need to be loaded 4k pounds or more per 'footprint' and the load repeatedly applied and removed.  Solar panels lose efficiency for two reasons - high UV and loading stress. 


Sigmetnow

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Re: Solar Roadways
« Reply #198 on: December 24, 2017, 09:28:17 PM »
Sandpoint, Idaho Solar Roadways installation — right now.

LEDs visible.
In daylight.
From a distance.
Snow melted. (Compare piles and ragged edge of snow where the bare sidewalk was shoveled.)

Edit: And these panels are not the latest, Version 4, panels!
About the visibility of the LEDs:
“…even on their brightest setting, the LEDs were difficult to see (and more difficult to photograph) in the daylight. We knew it would be a very easy fix for the next prototype, but it was frustrating not to be able to show the parking lot lights in the daytime.“

Photo below.  Webcam here:
http://www.sandpointidaho.gov/visiting-sandpoint/solar-roadways
« Last Edit: December 24, 2017, 09:48:31 PM by Sigmetnow »
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Sigmetnow

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Re: Solar Roadways
« Reply #199 on: December 24, 2017, 09:35:43 PM »
I thought I was done with this topic.  Guess not...

Quote
The load testing showed that a pavement made of our SR Panels could withstand a static load of 250,000 pounds. To put that in perspective, the national weight limit for semi-trucks is 80,000 pounds.

No, the test showed that the glass could withstand that load. 

Quote
Glass samples were also sent off

Now, how was the test performed?  A 250,000 pound load spread over what area?  An 80,000 pound truck divides its weight over 18 contact points (bottoms of wheels).  4,444 pounds per wheel.  Work that down to pounds per square inch (PSI).  Was the test 13,889 pounds per wheel footprint?  Was it the same PSI loading or was the load evenly spread over a piece of glass?

To test panels they would need to be loaded 4k pounds or more per 'footprint' and the load repeatedly applied and removed.  Solar panels lose efficiency for two reasons - high UV and loading stress.

I think the U.S. DoT is well aware of exactly how the panels must be tested!

I refer you again to the Solar Roadways website:  http://www.solarroadways.com/Research/Research
To wit:
Quote
November, 2015 – Solar Roadways Incorporated is awarded a Phase IIB SBIR (Small Business Innovative Research) contract by the U.S. Department of Transportation. The 2-year $750,000 Phase IIB contract includes additional civil engineering tests including:

Freeze/Thaw Cycling: Panels will be placed in an environmental chamber and exposed to extreme temperatures to make sure the mechanical/electrical systems hold up.

Moisture Conditioning: Additional environmental chamber testing. This time, the panels will be frozen into a block of ice and then thawed – many times.

Shear Testing: Panels will be subjected to high shear forces to simulate heavy vehicles braking.

Advanced Loading: Will simulate years of truck abuse in a matter of months.

While we plan to begin with non-critical applications such as driveways, parking lots, sidewalks, bike paths, etc., these civil engineering tests will get us closer to being ready for public roads and highways – our ultimate goal.
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