Author Topic: EEVblog #681 - More Solar Roadways BULLSHIT!  (Read 78353 times)

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Offline EEVblog

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #75 on: November 09, 2014, 11:39:46 pm »
(The figures Dave showed suggest you are approx 4x better to put the panels on your roof)

I goofed that figure actually, it should be 5x
And that is using best case measured data for a newly installed solar road system.
How can any intelligent reasoning human think this is in any way a good idea? :palm:
 

Offline EEVblog

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #76 on: November 09, 2014, 11:41:52 pm »
Maybe Dave can do a video on what needs to be changed to make solar roadways viable?

Nothing will make it viable, because you are missing the entire point. Solar roadways produce at best 1/5th the energy compared to an (always cheaper) rooftop solar system.
 

Offline Chasm

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #77 on: November 10, 2014, 01:29:06 am »
There is also another option. Not every study has the goal of proving that something can be done. Sometimes the actual goal is to prove that something does not work.
An example for this is GROWIAN, a major test installation for wind energy ~30 years ago. The topology, a two blade downwind turbine, was choosen knowing that it has major problems with bearing loads. And the study did deliver. Growian never worked for long, even after many cycles of re-engineering refits and rebuilds. Certainly nobody could say that the did not try or spend heaps of money on it. There is a reason why practically all wind turbines we see today are three blade upwind configuration.

Guess which lobby controlled that crucial parameter of the study...

That said, solar power is already proven.
Solar roadways? Maybe asn option after we run out of space on buildings. By then solar roadways should a better option than stupid stunts like replacing forests with solar farms. ;)
 

Offline NANDBlog

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #78 on: November 10, 2014, 07:45:51 am »
http://notrickszone.com/2014/09/24/eike-german-power-grid-more-vulnerable-than-ever-on-the-brink-of-widespread-blackouts/

Actually it's not nearly as bad as the UK is at the moment, mostly due to a series of accidents we suffered. Cracks in the reactors. Germany has the opposite problem - too much power. It will take them some time to adapt the grid to make best use of it, but they are doing pretty well. Let's see if they hit their target of a 40% CO2 reduction by the mid 2020s, and keep the lights on.
And in the meantime if they bring down europe with them, sorry about that, right?
http://en.wikipedia.org/wiki/2006_European_blackout
The whole grid is connected together, if one big country makes stupid things and makes the grid unreliable, they can send us back to the stone age. And btw, the most of the solar stuff doesnt work during a blackout.
 

Offline Teemo

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #79 on: November 10, 2014, 09:30:59 am »
Excuse me for coming in with different approach, but most efficient solar energy collecting and storing device to this day is invented by nature itself. It is the TREE. Living, growing tree collects sunlight with its leaves, and stores the energy in itself. Unfotunately best way invented to use that energy is to chop down the tree and burn it:( . But then we can plant a new tree and the cycle begins again:)
Trees growing roadside are the best solar roadways! And it is economical (cheap) too:) only need to invest in chainsaw and chimney:)
 

Online coppice

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #80 on: November 10, 2014, 09:44:24 am »
Excuse me for coming in with different approach, but most efficient solar energy collecting and storing device to this day is invented by nature itself. It is the TREE. Living, growing tree collects sunlight with its leaves, and stores the energy in itself. Unfotunately best way invented to use that energy is to chop down the tree and burn it:( . But then we can plant a new tree and the cycle begins again:)
Trees growing roadside are the best solar roadways! And it is economical (cheap) too:) only need to invest in chainsaw and chimney:)
There are much more effective solar collecting plants than trees, but your general premise is correct. Burning plant matter is environmentally near to harmless, as long as you start enough new plants growing to balance the ones you burn, and ensure the ash fertilizes those new plants.
 

Offline frvisser

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #81 on: November 10, 2014, 10:46:54 am »
Hey have a look at this. Another dutch project called http://plant-e.com. They make a sort of fuelcells with plants in it and it delivers about 5v dc. You don't have to chop down tree's for making use of their photosynthesis.
 

Offline sunnyhighway

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #82 on: November 10, 2014, 11:07:24 am »
Nothing will make it viable, because you are missing the entire point.

Lets define viable.

From my point of view viable means that it does not have to make a profit during its life-time. Even a slightly higher price point could be considered viable as there is the added bonus of cleaner air and the absence of horizon pollution. The economics of these are very complex.

It's just like designing an rf-cirquit. You can do all the calculations and simulations you like, but there will always be some parameters you didn't think of which can affect the final outcome. The only way to know for sure is to make a prototype and start measuring in the field. And that's just what the dutch did with this solar cycling-path, build a prototype and start measuring with a 3 million euro R&D budget.
 

Offline MadScientist

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #83 on: November 10, 2014, 11:17:36 am »
In my experience, almost none ( yes none) of these domestic "green" energy initiatives make any sense financially.  Almost everyone of them  has to be subsidised. The fact is that  hydrocarbons are cheaper then bottled water.

I and some of my friends, looked at solar hot water heating, wind power, PV generation, Nothing has less then a 10 year payback, lots has over a 20 years payback ( arguably greater then the life of the equipment). Thats not even taking into account the net future  value of money etc.

Even if you look at adding insulation to existing homes, the payback doesn't make sense, just buy more oil.

Unless these technologies fall dramatically in price, they will be consigned to the dustbin of history.

( PS I was amazed at one commentator , suggesting that to heat a 100sqm house in france ( yes an uninsulated one was costing €4000 a year - what I smell is BS)

Here in Ireland, we have some of the highest oil prices in Europe , Heating oil is now around €0.72 /litre. An average family home here ( typically rural as most towns have Naturel gas, which is much much cheaper) ,is around 160-200 sqm, and would rarely consume in excess of €2000-2500 to heat.  my house is 100sqm and is built to insulation standards of 1995, its costs under €1000  to heat. Heating season in Ireland would typically be End of September to May.

Thats make your original payback calculation way longer, approaching 20 years. a 20 year ROI is ridiculous


Very very few of these "green" initiatives  make sense, Oil is cheaper then bottled water or milk, until that changes really dramatically the situation will remain
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Offline EEVblog

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #84 on: November 10, 2014, 11:20:47 am »
Lets define viable.
From my point of view viable means that it does not have to make a profit during its life-time. Even a slightly higher price point could be considered viable as there is the added bonus of cleaner air and the absence of horizon pollution. The economics of these are very complex.

You are still missing the point. This project and nothing to existing solar power technology. It simply uses existing cells in the most inefficient and hostile way possible.
It's not rocket science to know this is a bad idea.

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The only way to know for sure is to make a prototype and start measuring in the field. And that's just what the dutch did with this solar cycling-path, build a prototype and start measuring with a 3 million euro R&D budget.

They didn't need to spend anywhere near that sort of money to get data out of a horizontal solar panel covered in thick glass.
Basically, just like Solar Roadways, they put the design of the cart before the horse. It's doesn't matter a rats about the glass and the physical stuff if the fundamentals of putting a solar panel in the worst possible environment is not sound.
 

Offline hli

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #85 on: November 10, 2014, 12:55:34 pm »
Nothing will make it viable, because you are missing the entire point. Solar roadways produce at best 1/5th the energy compared to an (always cheaper) rooftop solar system.
I did not mean viable as in 'better than putting solar cells on roof tops' - I stated that already. If you see that project under a pure economical perspective it surely makes no sense since the alternatives are better for a long time to come.
But it might be viable in the sense that one can use that technology in places where you need energy (but don't have it avaliable) and construct a roadway anyways, or where other places are already used (there are already oh so many rooftops in Germany occupied by solar cells...).
So I see the dutch project as kind of a feasibility study: can it work technically? What problems are to be solved from the technical perspective? E.g. from the photos it seems that there is much dirt on the glass, and nonetheless they claim to come close to the calculated energy output. That seems like an interesting result to me. And it would mean that there is no so much maintenance needed after all.
Also, there are other places where solar cells might be put on places where people walk or drive on (e.g. a yacht - roof space is kind of limited there...).
So I would like to think of what needs to be changed to get solar roadways to a cost point in the future to where solar cells on a rooftop are today. Since the latter are already economical viable, the former ones can be too. Even though in that future roof tops still are the better alternative, as long as they are available.
 

Offline redtails

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #86 on: November 10, 2014, 01:49:40 pm »
Okay, you can argue that the money would be better spent adding solar panels to roofs, but giving away free solar PV to private individuals is politically unpalatable. There is also the opportunity factor - in western Europe most countries try to plan transport budgets on 10 or 15 year timescales, so if the additional cost over the budget period is zero or fairly low then there is an opportunity to use that already allocated money.

I agree that if you were playing Sim City as a benevolent dictator and got to decide everything you would populate roofs first, but that's now how the world works.

European countries have been giving out subsidies (read: free money) to private individuals and businesses for purchasing solar panels for years. In fact, in recent years, many of the subsidies for solar panels have been decreased due to budget cuts.

I think the really politically unpalatable thing here is that PV subsidies are being cut, and the budget being shifted towards solar roads. In the scheme of things, these two are not related, and I technically cannot say that the budget has shifted from one to another. But from the perspective of an average Joe, you simply can't explain why the decision was made to grant money to solar roads while pv subsidies are being cut.
« Last Edit: November 10, 2014, 01:53:56 pm by redtails »
 

Offline NANDBlog

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #87 on: November 10, 2014, 03:14:41 pm »
http://en.wikipedia.org/wiki/2006_European_blackout

Um, you realize that was five years before they even announced their intention to shut down their nuclear plants?
I gave you an example, how germany can shut down europe. It has nothing to do with nuclear plants. It is the fragility of the power grid. Sure, less nuclear means it is a bit more flexible, but more solars means also less flexible. In fact, dangerous. And the awesome politicians are indeed giving money for solar installations, because people like that. Free money. If the network cannot handle it in fifteen years, well, that is someone else's problem.
It doesnt take too much to state the facts:
Renewable energy will grow
Renewable energy fluctuates
The grid doesnt have any capacity to store energy
All available energy must be used
Alternative solutions cannot act fast enough the fluctuations
Without energy we die (pretty much)
We dont have any plans to store energy, make the grid more flexible, speed up the existing power plants or compensate the fluctuations any other way. Not on the city  scale, not on a country scale, not on the global scale. No plans.
 

Offline Artlav

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #88 on: November 10, 2014, 05:14:41 pm »
They didn't need to spend anywhere near that sort of money to get data out of a horizontal solar panel covered in thick glass.
Basically, just like Solar Roadways, they put the design of the cart before the horse. It's doesn't matter a rats about the glass and the physical stuff if the fundamentals of putting a solar panel in the worst possible environment is not sound.
Well, a negative result is also a result.
You tried, you failed, you got wiser.

But one should try, just in case there is something interesting in the concept, or some more problems that were not anticipated.
While a road is not one of them, there might be circumstances where putting solar panels behind reinforced horizontal glass would be the best option, and now we know what the difficulties are.
Abstract knowledge.
Hacking the universe since 2008
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Offline miguelvp

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #89 on: November 10, 2014, 07:39:47 pm »
They didn't need to spend anywhere near that sort of money to get data out of a horizontal solar panel covered in thick glass.
Basically, just like Solar Roadways, they put the design of the cart before the horse. It's doesn't matter a rats about the glass and the physical stuff if the fundamentals of putting a solar panel in the worst possible environment is not sound.
Well, a negative result is also a result.
You tried, you failed, you got wiser.

But one should try, just in case there is something interesting in the concept, or some more problems that were not anticipated.
While a road is not one of them, there might be circumstances where putting solar panels behind reinforced horizontal glass would be the best option, and now we know what the difficulties are.
Abstract knowledge.

Or they could have goggled Google's experience with horizontal solar panels 5 years ago:
http://googleblog.blogspot.com/2009/07/should-you-spring-clean-your-solar.html

current 150W solar panels that are 1 sq meter and produce about 0.75 kWh per day cost about $190 times 124 that would be $23560 for the whole thing, or 18953 euros which is around 80% the cost of a single solar pathway square meter.

With 3 million euros they could have bought 19627 sq meters of panels (of course you need to install them) giving an output of 14720 kWh per day.

So yeah expensive exercise to just attract public attention, on the wow factor, this is cool, we have to just do it, it makes us look green, give employment it's a great political gain! woohooo!


 

Offline LabSpokane

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #90 on: November 11, 2014, 06:29:53 am »
Be honest, which type of solar panel would you choose for this cycling path?

Honestly, why on earth would one out solar photovoltaic underneath the ground? Because that's exactly what has happened. This experiment is already soiled to uselessness. And the shading issue is worse than some assume, since shading one cell or panel essentially nullifies the output of the entire string of cells or panels.

No one needed to spend €3M to learn the already known. The most telling aspect of all this is that at no point is the actual output of this system revealed. For €3M, one could readily install 1-1.5 MWe solar farm, save for grid interconnects and the price of dirt.  This solar bike path is so poorly executed,I would be shocked if it produced more that a dozen kilowatts at noon.
 

Online coppice

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #91 on: November 11, 2014, 08:25:10 am »
And the shading issue is worse than some assume, since shading one cell or panel essentially nullifies the output of the entire string of cells or panels.
Most solar panel systems deal with the partial shading problem these days. Do you have evidence that this one doesn't?

The system is dumb enough. You don't have to make it appear even dumber.  :)
 

Online coppice

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #92 on: November 11, 2014, 09:31:04 am »
There is already energy storage in Germany and most other European countries. We are already dealing with the fluctuations very well, thank you.

As it happens renewables are actually less variable than nuclear or coal over the short term. The UK National Grid has done a lot of work in this area and concluded that renewables are more reliable. The simple fact is that if the wind is blowing at 20 km/h now it will only vary by 1-2 km/h over the next 15 minutes. If a turbine fails you lose a few megawatts. If a cloud passes over your solar PV output only drops slightly, unless it is a large cloud front which is also easily predictable. Compare that to say nuclear where if a turbine goes down you like lose 500MW or more instantly and without any warning, meaning you need much more spare capacity on-line all the time.
Where do you get your information? It is in serious conflict with most other information I see.

Storage is a *huge* problem. Even massive storage projects like Dinorwig can only storage quite modest amounts of energy. Dinorwig wasn't particularly costly by energy industry standards, but its huge. You can't build large numbers of things like that, and you need them if you rely on solar or wind. Solar is out of action for many hours a day, and performs poorly in winter. Wind can be out of action for many days at a time. Massive amounts of storage are the only way to avoid the need to have enough traditional power stations to cope with nearly 100% of the load.

Wind does die quite abruptly over surprisingly large areas, especially in places like the UK where the wind tends to be rather gusty and turbulent. I've seen quite a few wind turbines on trips to the UK, but I have rarely seen one operating properly. They seem to be idle a large percentage of the time. Heavy cloud cover kills the output of solar systems, and this is a very frequent event in many countries. They don't do well in northern winters, either.

If you lose a traditional 600MW turbine set you've lost 600MW. If you lose appropriate weather you've lost whatever percentage of your regional capacity that relies on that weather.

Its hard to get honest information about anything to do with energy. There is so much money tied up in the energy industries, and so many vested interests trying to promote their cause. However, some basics are pretty much self evident.
 

Online coppice

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #93 on: November 11, 2014, 02:22:47 pm »
Wind does die quite abruptly over surprisingly large areas, especially in places like the UK where the wind tends to be rather gusty and turbulent.
You are thinking on a much to small scale. Turbines have a great deal of mass and don't rotate at exactly the speed of the wind on a second-by-second basis.
Ever tried slaming a big load across a free wheeling generator? They almost stop dead. The mass of a typical 4MW turbine is tiny on the scale of its 4MW rated output. If the drive (i.e. wind) falls, the natural tendency of the turbine would be to slow at about the same rate as the wind falls, even if it falls over just a couple of seconds (unless this is during a very lightly loaded period, of course). You can't allow that to happen in a practical design, so a tight control system sheds and takes up load dynamically to keep the speed constant. Only when the wind is too weak to keep an unloaded turbine up to speed will its speed change.
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I've seen quite a few wind turbines on trips to the UK, but I have rarely seen one operating properly. They seem to be idle a large percentage of the time.
This is a myth created due to people looking to discredit wind power looking for turbines not in operation. If you simply examine the national wind power output of the UK it is clear that most of the turbines work "properly".
The UK wind industry quotes something like 80% average generating time for the installed UK wind farms, and an average of about 30% of installed capacity generated over a year. Others point out large holes in how those rather rosy numbers are arrived at. As I said before, I don't put too much credence in anything said about energy, as the huge amounts of money involved give everyone an agenda. I don't know who to believe, but on my rare viisits to southern England I see quite a lot of wind turbines, and few of them are turning. Do I happen to always go there at the wrong time to see them working?
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Heavy cloud cover kills the output of solar systems, and this is a very frequent event in many countries. They don't do well in northern winters, either.
It doesn't "kill" the output, it reduces it. Also, cloud cover is extremely predictable over the short term because we have weather radar. There is plenty of time to spool up backup generation. Clouds don't appear out of nowhere all of a sudden.
Figures for southern England say typical solar output is about 4Wh per day per watt of solar capacity, and 1Wh per day in winter. The difference between sunny and overcast days is much more extreme. So, the averaged output during high demand (winter) is 1/4 of the output during low demand (summer). It sounds like a lot of storage will be needed there, or a lot of generation you can fire up on demand. Overcast days are not generally one offs. They occur in runs of several days at a time, and output is nearly zero on those days. That also sounds like a lot of storage will be needed, even if the 1wH per day capacity of your installed base is made large enough to meet the average winter demand.
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If you lose a traditional 600MW turbine set you've lost 600MW.
Yes, but for that to happen all the turbines in the set, say 50 in a 600MW set, would have to fail simultaneously.
Who uses 50 little turbines? A traditional 600MW turbine+generator set is a single item. You either have it on line or you don't.
 

Online SeanB

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #94 on: November 11, 2014, 03:33:39 pm »
Here load shedding is happening because a silo collapsed "totally unexpectedly" from a structural crack that grew over a few months. That has shut down a whole plant that provides around 10% of the total capacity.

Now consider that any wind and such generation that is at best intermittent will need some form of storage ( limited spaces that are good for that, few countries have large plateaus and plains which are separated by a few dozen metres in height and by an easy to traverse mountain range) and no power company will build a large high capacity plant and leave it idle for most of the time, or worse still powered up and running as spinning reserve for immediate despatch, at no income but with fuel cost and maintenance.
 

Offline LabSpokane

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #95 on: November 11, 2014, 04:17:52 pm »
And the shading issue is worse than some assume, since shading one cell or panel essentially nullifies the output of the entire string of cells or panels.
Most solar panel systems deal with the partial shading problem these days. Do you have evidence that this one doesn't?

The system is dumb enough. You don't have to make it appear even dumber.  :)

Solar systems deal with shading through the use of bypass diodes to shunt power past a row of cells or panel with one or more cell shaded. Perhaps they have bypass diodes working differently than I expect such as a diode bypassing every cell, but what I saw through the rough surface appears to be rows of  cells wired in series, so  at least the row that is protected by the bypass diode is nullified if one or more cells in that row are shaded.  Most commercial solar panels bypass on a panel basis, so one shaded cell causes the loss of generation of the entire panel.

 And there appears to be plenty of rows in those panels that are basically non-functional due to soiling.

Worse yet is the anticipated total output of approximately a paltry 3kW when the solar road is completed in 2016. Such a waste of resources is virtually criminal.
« Last Edit: November 11, 2014, 04:23:35 pm by LabSpokane »
 

Online coppice

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #96 on: November 11, 2014, 04:31:38 pm »
Solar systems deal with shading through the use of bypass diodes to shunt power past a row of cells or panel with one or more cell shaded. Perhaps they have bypass diodes working differently than I expect such as a diode bypassing every cell, but what I saw through the rough surface appears to be rows of  cells wired in series, so  at least the row that is protected by the bypass diode is nullified if one or more cells in that row are shaded.  Most commercial solar panels bypass on a panel basis, so one shaded cell causes the loss of generation of the entire panel.

And there appears to be plenty of rows in those panels that are basically non-functional due to soiling.

Worse yet is the anticipated total output of approximately a paltry 3kW when the solar road is completed in 2016. Such a waste of resources is virtually criminal.
A mismatch between the dominant areas of dirt accumulation and the shaded cell bypass pattern might be embarassing for someone..... unless the goal is to fail.

They used to bypass in large chunks, as bypassing each cell could result in a long chain of diodes each dropping 0.7V when there is significant shading. Now there are special bypass devices which drop very little, and you can afford to bypass each cell.
 

Offline LabSpokane

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #97 on: November 11, 2014, 04:35:44 pm »
Solar systems deal with shading through the use of bypass diodes to shunt power past a row of cells or panel with one or more cell shaded. Perhaps they have bypass diodes working differently than I expect such as a diode bypassing every cell, but what I saw through the rough surface appears to be rows of  cells wired in series, so  at least the row that is protected by the bypass diode is nullified if one or more cells in that row are shaded.  Most commercial solar panels bypass on a panel basis, so one shaded cell causes the loss of generation of the entire panel.

And there appears to be plenty of rows in those panels that are basically non-functional due to soiling.

Worse yet is the anticipated total output of approximately a paltry 3kW when the solar road is completed in 2016. Such a waste of resources is virtually criminal.
A mismatch between the dominant areas of dirt accumulation and the shaded cell bypass pattern might be embarassing for someone..... unless the goal is to fail.

They used to bypass in large chunks, as bypassing each cell could result in a long chain of diodes each dropping 0.7V when there is significant shading. Now there are special bypass devices which drop very little, and you can afford to bypass each cell.

What is this "special bypass device?" An ideal diode in the form of a MOSFET plus a controller?  Which panel manufacturer is using it on a cell by cell basis?
 

Online coppice

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #98 on: November 11, 2014, 04:46:01 pm »
What is this "special bypass device?" An ideal diode in the form of a MOSFET plus a controller?  Which panel manufacturer is using it on a cell by cell basis?
That's basically what they are. TI makes them, but I don't think they are alone. I've seen prototypes using them. I think people have them in mass production.
 

Offline LabSpokane

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Re: EEVblog #681 - More Solar Roadways BULLSHIT!
« Reply #99 on: November 11, 2014, 05:22:23 pm »
The controller itself has a published price of about a dollar. So maybe it's $.50 in volume. Add a $.50 MOSFET and do that for each of the 36+ cells on a typical panel and you have one very expensive solar panel.  I'm still betting that the bypass diodes are done on a string basis of approximately 15-18 cells per "diode" - ideal or actual.
 


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