EEVblog #632 - Solar Roadways Are BULLSHIT!

[Fungus]

About the only good thing for a solar road is it is flat, it is not any more proof against either nature of Yoof wiv an Hattitude, who will damage it. Only those who cannot find a rock, hammer or anything heavy to drop on it will not damage it.

That's bothered me as well. As soon as they find out how much fun it is to break roads they'll be all over it, innit.

Plus what happens if a sharp object falls off a lorry. Doesn't matter how tough you make glass, it's still vulnerable to being bashed with pointy objects.

nb. Yes, the whole idea is a fail, this is just one more reason.

[TheNewLab]

 Just watched this vid.  Some other considerations;

Wouldn't traffic reduce amount of solar recv'd by panels? maybe not on back road stretch, but on a major street with traffic? Freeways? again back roads sure, only aren't the LEDs more important for major routes.

So let's say  they actually work on the road and are actually safe. Let's say the US govt pays both for the product and labor ( like an Eisenhower massive highway program.) Lets say these panels last ten years..
 What about the cost of maintenance? I suspect it would end up a great make work project that would end up disappearing.

Electrical engineering aside, I just cannot get past tires on glass and having to brake...at all. let alone hard..on in wet weather.

Being solar though, I would really like to see something that would work. not so much on the road itself..just lighting back road signs would be nice. or using the stuff for a walkway...

[EEVblog]

UPDATE!
Solar Roadways have released DATA!
http://solarroadways.com/data

Oh, what's that, it's not data on their panels, but just commercial panels placed around the place to get some data on the difference between flat panels and tilted panels 
That's what they release after all these years!
 

[LabSpokane]

Those guys just redefined the lower bound of stupid. 

[timgiles]

Those guys just redefined the lower bound of stupid. 

Erm.... I dont get it. Looks to me like in 80% of month-locations, the tilted are better. Where I live, roads are not flat, they follow the lie of the land.

 

I thought the internet was meant to make us (the human race) better, clever-er (he he), at least better informed - instead we the Inde-my money-go go go, Kick-me in the face-starter (and steal my money) and the idea that placing solar panels where objects will be over them as part of the design!

 

[HackedFridgeMagnet]

Snow? No data because of four months of snow?

"Snow" indicates months where no data was collected because the panels were covered in snow and collected zero solar energy. Keep in mind that Solar Roadways will collect solar energy in every kind of weather as the panels will never be covered in snow thanks to our heating elements.

At some point this is clearly not feasible they should just admit that. That point is probably somewhere near the equator. 

[coppice]

"As can be seen from the data collected so far, the flat panels generate more energy than the tilted panels during overcast days. "

They don't seem to be showing that data. They do show that in some months the flat panel produces more than the tilted one,  but they don't seem to present any data tying that to overcast conditions. It seems logical that this would relate to overcast weather, but they aren't even making a minimal effort to present a case supporting that.

[daqq]

Finally, with this new information a new era of solar power can begin.

[EEVblog]

Finally, with this new information a new era of solar power can begin.

Ground breaking research! 

[CaptCrash]

From the data that has been published, I think that the following can be stated (with the caveat, that there is very little data).
For all of the following I have used the 12 months of data 2015 June - 2016 May (the first record has been ignored).

1. Mounting the panels in an angled layout provides for a performance improvement of 12.4% across the test sites.
No big surprise here

Method:
Sum the power output of all flat panels 568.8 Kw
Sum the power output of all angled panels 639.3 Kw
Take the difference between these figures and calculate the % improvement based on the lower number
(639.3 - 568. / 568.8 = 12.4%

2. Flat mounted panels perform in a more irregular manner than angled panels providing for an unoptimised output.
Flat mounted panels vary by 2.2x over the test period in the amount of power produced, angled panels are more stable in their power production with a ratio of 1.6.

This then provides a further issue, where additional panels would be required to maintain a given base load over the year.  The variability in the performance of the panels over the year will mean that additional capacity would be required at various times of the year (37.5% more panels needed during low output months).

Method
When looking at the monthly power output of a panel, calculate its proportion of the total power produced and express as a percentage.
Find the max value for each panel
Find the min value for each panel
Calculate the ratio of each panel (min:max) and then provide an average of the three panel locations.

3. The data from Chesterfield, MO looks a bit odd.  In two of the three samples, the flat panel has significantly out performed the angled panel.
In no other test data did the flat panel so significantly outperform the angled panel.  With only three samples there is not really enough data to accurately suggest an answer, though it does raise some questions

a. Is there an issue/fault with one of the panels or inverters?
b. Are the mounting locations of the panels are being affected unevenly by the trees to the west of the installation location (assuming this is the panels https://www.google.com.au/maps/dir/38.6378614,-90.5167265/Missouri+Department+of+Transportation,+1590+Woodlake+Dr,+Chesterfield,+MO+63017,+USA/38.639774,-90.5159339/@38.639753,-90.5160978,59m/data=!3m1!1e3!4m10!4m9!1m0!1m5!1m1!1s0x87d8cda70a6fd38b:0x2b4c54d496dfbc0d!2m2!1d-90.5162299!2d38.6398386!1m0!3e2?hl=en)?
c. Have the ID's/data for the micro-inverters have been swapped in error?

If the data is incorrect and has been swapped in error, this would move the overall improvement in power production for angled panels to 16.1% rather than 12.4% (Flat 559.1 Kw Angled 649 Kw).
It would also improve the variable nature of power production of the flat cells from 2.2x to 2.1x and worsen the variable nature of the angled cells from 1.6x to 1.66x

This would lead to the following results in terms of power production of flat panels vs angled panels, with the percentage being the improvement in power that the angled panel can produce.
Oracle, AZ 117%
Chesterfield, MO 116%
Eagle, ID 115%

In terms of a data credibility question, this would look to be the most likely cause.  Otherwise, for some reason in Chesterfield, the flat panels have out performed the angled panels by 30% which seems unlikely.  Though they are a different panel from the other locations, so this may be possible, but it would seem unlikely for a manufacturer of panels to optimise of for this flat installation and to be detrimental in an angled installation.

It is also worth noting that nothing in the data page mentions the actual angle utilised in the three test locations.  It is unclear if optimum angles have been used for each location, or a common angle has been utilised.

Summary
By mounting panels on an angle produces 12.4%-16.1% more power and has significantly more stable level of power production.
On top of it being a silly idea to make a glass road, put panels under it, make the surface textured to reduce light penetration, obscure the panels with cars/trucks/dirt/oil etc, reengineer roads and power connectivity.  It also adds a significant level of increased variability to the supply of power.

  Great work solar roadways, Im not sure if it would have been possible to post data that undermined your concept more, other than perhaps data from the angled panel, a flat panel and one of the Solar Roadways Hexagonal units, with the textured glass and a typical amount of debris that would be found on an equivalent area of roadway.

[System Error Message]

so many arguments.
I thought i should mention a few interesting points though. With such a road you dont need heating elements. The power circuits will produce heat which will be consistent, good to melt snow so just by using the heat from energy loss in making electricity you save even more power instead of using energy for a heating element.

Its not good to talk about money in the sense of making something because raw materials vary in cost from time to time and from manufacturer to manufacturer. China has built many ghost cities.

I think putting solar on top buildings will be better because in the City or highway if you have traffic jam than you're covering the road. Sidewalks, the lane bits of a parking lot, buildings would be better for solar rather than roads which are covered as they are driven on. People dont block more sun than cars. Solar covered telephone poles and bus stops as they also double as a roof during rain doubling as a roof for your walkways during rain.

The project may be legit but the idea and implementation very inefficient.

[gildasd]

1. Mounting the panels in an angled layout provides for a performance improvement of 12.4% across the test sites.
No big surprise here

Lets just make conical car and truck wheels then! Problem solved*!


*Wheel chairs, baby carts, motorbikes and bicycles might be inconvenienced.

[Delta]

so many arguments.
I thought i should mention a few interesting points though. With such a road you dont need heating elements. The power circuits will produce heat which will be consistent, good to melt snow so just by using the heat from energy loss in making electricity you save even more power instead of using energy for a heating element.

Its not good to talk about money in the sense of making something because raw materials vary in cost from time to time and from manufacturer to manufacturer. China has built many ghost cities.

I think putting solar on top buildings will be better because in the City or highway if you have traffic jam than you're covering the road. Sidewalks, the lane bits of a parking lot, buildings would be better for solar rather than roads which are covered as they are driven on. People dont block more sun than cars. Solar covered telephone poles and bus stops as they also double as a roof during rain doubling as a roof for your walkways during rain.

The project may be legit but the idea and implementation very inefficient.

The crux of the matter is simply that underneath a bloody road is about the worst place you could ever install PV panels.

The idea is utter stupidity, and has zero redeeming features.

[Brumby]

1. Mounting the panels in an angled layout provides for a performance improvement of 12.4% across the test sites.
No big surprise here

Lets just make conical car and truck wheels then! Problem solved*!

I'd LOVE to see you in action in a brainstorming session!!

[Delta]

1. Mounting the panels in an angled layout provides for a performance improvement of 12.4% across the test sites.
No big surprise here

Lets just make conical car and truck wheels then! Problem solved*!

I'd LOVE to see you in action in a brainstorming session!!

The round wheel is SO last millennium!

[gildasd]

1. Mounting the panels in an angled layout provides for a performance improvement of 12.4% across the test sites.
No big surprise here

Lets just make conical car and truck wheels then! Problem solved*!

I'd LOVE to see you in action in a brainstorming session!!

I've been banned from attending.

[coppice]

1. Mounting the panels in an angled layout provides for a performance improvement of 12.4% across the test sites.
No big surprise here

Lets just make conical car and truck wheels then! Problem solved*!

I'd LOVE to see you in action in a brainstorming session!!

I've been banned from attending.

They ask you to think outside the box, but when you do you find yourself outside the room.

[Galenbo]

...With such a road you dont need heating elements. The power circuits will produce heat which will be consistent, good to melt snow so just by using the heat from energy loss in making electricity you save even more power instead of using energy for a heating element.

You have a huge underestimation of the efficiency power circuits reached in these years, and a bad understanding of the amount of joules you need to melt snow.
And combined: How to melt snow on panels with the unefficiency of circuits that convert no energy because the panels are under that snow?

[dr.diesel]

...With such a road you dont need heating elements. The power circuits will produce heat which will be consistent, good to melt snow so just by using the heat from energy loss in making electricity you save even more power instead of using energy for a heating element.

You have a huge underestimation of the efficiency power circuits reached in these years, and a bad understanding of the amount of joules you need to melt snow.
And combined: How to melt snow on panels with the unefficiency of circuits that convert no energy because the panels are under that snow?

Yup.  During the winter my roof mounted panels stay covered in snow for weeks at a time, and they have micro inverters mounted under each one.

[EEVblog]

...With such a road you dont need heating elements. The power circuits will produce heat which will be consistent, good to melt snow so just by using the heat from energy loss in making electricity you save even more power instead of using energy for a heating element.

You have a huge underestimation of the efficiency power circuits reached in these years, and a bad understanding of the amount of joules you need to melt snow.
And combined: How to melt snow on panels with the unefficiency of circuits that convert no energy because the panels are under that snow?

It's the most retarded idea in history.
It should be a standard exercise for engineering student to figure out why the idea is so stupid.

[EEVblog]

The crux of the matter is simply that underneath a bloody road is about the worst place you could ever install PV panels.
The idea is utter stupidity, and has zero redeeming features.

Actually it does. It's incredibly good at generating publicity and revenue.

[Brumby]

...With such a road you dont need heating elements. The power circuits will produce heat which will be consistent, good to melt snow so just by using the heat from energy loss in making electricity you save even more power instead of using energy for a heating element.

You have a huge underestimation of the efficiency power circuits reached in these years, and a bad understanding of the amount of joules you need to melt snow.
And combined: How to melt snow on panels with the unefficiency of circuits that convert no energy because the panels are under that snow?

Yes ... I didn't do any math, but I, too, had an adverse reaction to the idea.

I mean, it's only logical when you think that with all the solar radiation falling directly on the snow, it still remains frozen for some time, so how could solar cells underneath the snow magically create increased melting?

The crux of the matter is simply that underneath a bloody road is about the worst place you could ever install PV panels.
The idea is utter stupidity, and has zero redeeming features.

Actually it does. It's incredibly good at generating publicity and revenue.

... and that's about it.

[EEVblog]

Oh dear, a trial underway, and it will be crowd funded! 
http://www.globalconstructionreview.com/news/solar-paving-ma8ke-first-pub4lic-us-appear5ance/

[coppice]

so many arguments.
I thought i should mention a few interesting points though. With such a road you dont need heating elements. The power circuits will produce heat which will be consistent, good to melt snow so just by using the heat from energy loss in making electricity you save even more power instead of using energy for a heating element.

Try looking up the latent heat of melting water.

[System Error Message]

...With such a road you dont need heating elements. The power circuits will produce heat which will be consistent, good to melt snow so just by using the heat from energy loss in making electricity you save even more power instead of using energy for a heating element.

You have a huge underestimation of the efficiency power circuits reached in these years, and a bad understanding of the amount of joules you need to melt snow.
And combined: How to melt snow on panels with the unefficiency of circuits that convert no energy because the panels are under that snow?

While snow requires a lot of energy there is one other factor, time. You can melt snow using a low heat output but it will take longer. All those power distribution, power converters and all other components they produce heat so why be wasteful. Think about it this way, this system will be running the whole time, LEDs and power still distributed at night. Snow doesnt come down as 1 big lump, it comes down as flakes. Its only in places that get really really bad snow like the far north where the snowstorm is so thick that you cant see a thing and you get snow coming down onto the road from the slope next to it that you would need heating elements.

But the friction properties of the glass is important because when you melt snow you get water and this can make it slippery and if theres snow on the pavements and the road is angled to help with water dissipation the water could collect and make things worse.