One shaded solar panel dragging down the system - switch it off?

[Weight]

Canine. My Renogy 12V100W panels do not act like that. There is a diode on each panel. Diode is inside the weather proof box on the panel.

 

[John61CT]

“Dutch build quality / engineering“

Lol, I never knew that was a thing. Tulips, beer, hashish, Victron?

But of course you know that Victron products are actually made in India.

And Apple in China.

Location of the factory is irrelevant, as long as the brand owner puts in the required QA processes / systems and is diligent in oversight.

And yes, northern European business culture is well known for such diligence and attention to details.

A global 5-year warranty speaks to that aspect as well.

Is it really necessary to spell all this out? Sheeesh

 

[John61CT]

Here is how a shaded panel drains power in a parallel system

But not all, maybe not even most.

With a flexible MPPT controller tgat lets you go serial or parallel as you desire, easy enough for the owner to do A/B testing.

Many people when they do so, find that partial shading on paralleled panels has little impact on output, beyond the %age of shade cast.

If partial shading is likely

The ideal remains 1:1 :: SCanel

The worst is serial

And parallel is in between.

 

[Canine]

You guys, I just explained to you how that works. How can you possible deny that? Those are the facts. Weight, look at where that last diode is. Is it blocking electricity from going into the panel? No! Look at it. All you have to do is look. If you want to pretend that electricity won't take the path of least resistance without it being blocked, that is up to you. Facts clearly don't matter here or much of anywhere else for that matter. John, your prose is sooo difficult to read. I'm not sure what you wrote, but it appears you are disagreeing with me. What I wrote is factually true. If you want to twist it around like other people, that is your choice as well. I'm going to leave the facts to stand for themselves.

If that isn't good enough, so be it. It's your solar; you can do what you want with it. I just have a problem with you misleading other readers on here who are trying their darndest to do it right.

 

[John61CT]

I am not paying attention here to the underlying whys and hows.

I am saying it is a fact **on many parallel systems** that the reduction in watts output is roughly proportional to the % of partial shading.

In the past I thought that 30% shading on one panel could pull down total output by half or more, on all paralleled setups

which made the case for 1 SC per panel stronger.

That argument still holds for serialing panels.

And again, a Victron MPPT gives the flexibility for **anyone** to test **for themselves** which of the three options works best for **their** panels and setup,

and also test the impact of various shading scenarios

without having to decide in advance.

 

[bonvanroulez]

And Apple in China.

And the quality of Apple’s made in China products is exemplary, but I have never, ever heard it referenced as “Cupertino build quality” or "USA build quality".

Location of the factory is irrelevant, as long as the brand owner puts in the required QA processes / systems and is diligent in oversight.

I suspect this is doublespeak for you didn’t actually know that Victron products were made in India.

And yes, northern European business culture is well known for such diligence and attention to details.

But you said Dutch. Just for fun I googled “Dutch engineering”. The top result was the tale of the little boy that stuck his finger in the dike. I’m sure the Dutch have some great accomplishments, but unlike "German engineering" or "Swiss precision", no, “Dutch engineering” is not a thing.

A global 5-year warranty speaks to that aspect as well.

A warranty is meaningless if it’s not backed up with good service and support. I doubt you have had personal experience with Victron’s rather lame support.

Do you actually own or use any Victron products in real life? Or like so many other of your recommendations is your touting of Victron products simply parroting what you’ve read on the marine and sailing forums? Please do tell us of your actual personal experiences with Victron products.

I am an actual Victron owner/user, and will say that it’s a pretty good value for a product that works pretty well, albeit with some buggy firmware/software, but that it’s design and build quality are far from exemplary. 

Is it really necessary to spell all this out? Sheeesh

Sheesh indeed

 

[tx2sturgis]

How much shading and where the shading occurs on the panel also makes a difference, but I don't want to get into that.

I will. 

There is a difference between partial shading in the daytime, with SOME light falling on the panel, versus ZERO photons falling on the panel surface, such as pitch black night, or packaged in it's shipping carton.

Even a partially shaded panel will show some output, more importantly it will hold some voltage, usually counteracting reverse flow, and prevention of dragging down the remaining panel's output when wired in parallel. In series, YES...the entire series string will show a lower output to the controller.

This is a fundamental advantage to using panels in parallel: The entire system will be more tolerant of partial shading of one or more panels.

If a panel is completely 100% blocked from receiving sunlight, (such as at night) then, of course, it's voltage will drop to zero.

And only then could reverse current occur if there are no blocking diodes. 

I have seen my panels show about 3 volts simply sitting under a street lamp at night. No power was being produced, since that is not enough to charge a battery or wake up the controller.

 

[Weight]

Sorry to disappoint. I have four 100 watt Renogy panels parallel through a 45 amp PWM MorningStar controller feeding my EGC2 battery bank. If one or more panels are >partially< in shade I do not even notice the reduced charge at the battery. If one panel is blocked out with a cover, that is >totally< in shade, the other panels keep on trucking and I see 16 to 19 amps charging at the Victron battery monitor. I have done this. I know how my system works.

 

[John61CT]

I just went to look at a Quattro, says made in the Netherlands, I know I've seen Made in China.

So again, it doesn't matter at all where made, very few of there products are subpar afaic.

And yes, American products certainly do have a decent worldwide reputation once exported, or even when the factory's been outsourced.

Finally the Dutch and Europe in general do have very high standards for quality export products across the board.

If you are trying to claim Victron is not good quality, have fun with that!

 

[Canine]

I give up. I will let the readers decide what is misinformation or what isn't. I'm not going to keep arguing; that isn't helping anyone.

 

[John61CT]

I have seen my panels show about 3 volts simply sitting under a street lamp at night. No power was being produced, since that is not enough to charge a battery or wake up the controller.

Yes voltage means nothing without watts or amps.

I remember some idiot, claimed to be a solar professional, raving last year how great his high tech Renogy panels were especially great with shading, and that they charged just fine from moonlight or streetlights or something

8-D

 

[John61CT]

Sorry to disappoint. I have four 100 watt Renogy panels parallel through a 45 amp PWM MorningStar controller feeding my EGC2 battery bank. If one or more panels are >partially< in shade I do not even notice the reduced charge at the battery. If one panel is blocked out with a cover, that is >totally< in shade, the other panels keep on trucking and I see 16 to 19 amps charging at the Victron battery monitor. I have done this. I know how my system works.

Exactly.

However other panels, or your panels on a different SC may well show very different results.

 

[bonvanroulez]

If you are trying to claim Victron is not good quality, have fun with that!

Not to derail this thread further, I think a new thread to discuss Victron products would be very interesting, I think I will start a thread sometime soon. I hope some actual Victron users will join the discussion.

 

[bonvanroulez]

I remember some idiot, claimed to be a solar professional, raving last year how great his high tech Renogy panels were especially great with shading, and that they charged just fine from moonlight or streetlights or something

"Idiot"?  That's pretty harsh. I remember that thread. I believe the person you are calling "some idiot" was member GotSmart, although later in that thread HDR agreed with his statement.

Renogy Eclipse panels?

 

[Weight]

Yes, John. That is why qualified my results with the equipment list. I believe any quality nominal 12 volt parts would have the same results. I suspect panels designed for roof top fixed location uses, do not have the necessary diode. They would also require MPPT controllers.

 

[Canine]

It's quite difficult to determine where to draw the line between being nice and not hurting people's feelings while standing up for what you believe in.

I'm going to make a stand here. Since I know that I am 100% correct without any doubt in any way whatsoever, I want the readers to know how electricity works. When a panel is shaded and doesn't have a diode between it and the electricity, the panel becomes a consumer of electricity not a producer of electricity. Why do charge controllers have diodes in them? To keep electricity from flowing back into the panel. That is simply how it works. Before charge controllers, diodes alone were used to stop the flow of electricity. I can't in good conscience let this go. Anyone can state their meter reads that their panels don't consume electricity when shaded, but that narrow, empirical evidence pales in comparison to the laws of physics.

But that's me. Perhaps I'm the deluded one? I've seen a number of people who have misapprehend what is right in front of their nose; am I one of those people? Of course I don't think so. Then again, I'm one person conflicting with a number of people. No one has backed me up stating, "Hey. Canine is correct." You guys being backed by others and me being the only one doesn't bode well for me.

I also want to be a part of a community, but I don't want to be a part of a community that doesn't back up absolute, undeniable facts. If I wanted that, I'd move to San Fransisco. And if something completely beyond my control were to happen to me and I needed help, I can see you guys that haven't backed me up folding like a lawn chair, leaving me swinging in the wind. It's happened before and hopefully, won't happen again. (This of course doesn't include the people who don't know how electricity works. Some do know, though, and haven't said anything.)

Or perhaps, again, I'm the one causing problems and don't deserve that kind of support. In that case when I make my bed, I need to lie in it without dragging others down. I don't want anyone enabling me.

I wish facts didn't matter so much to me; I'd have more friends. What is happening in this thread is what has happened in real life several times. Eh, what are ya gonna do?

Either I'm right and don't want to be bogged down by ignorance or I'm the deluded one foisting my ignorance on the neophytes that frequent this site. Not cool. Either way, I don't want to be a part of that. What I want is this site to be a largely authoritative site for those who want to be free from their unwittingly conditioned restraints of the world, which I believe to be at least partially in line with CheapRVLiving.

That isn't to say I will eschew CRVL in its entirety. I'll just be a part of it in Real Life and with a more selected group of people.

As soon as this is posted, I'm going to ask a moderator to cancel my account. This is the only thing I can think of to do to right this wrong- passively make a stand. Let the username Canine stand as a martyr for proven, true facts.

Stand up for what you believe in even if it means standing alone.

Toodles,

-Canine

 

[John61CT]

When a panel is shaded and doesn't have a diode between it and the electricity, the panel becomes a consumer of electricity not a producer of electricity. Why do charge controllers have diodes in them?

I don't believe anyone was disagreeing with this.

My disagreement was with a statement along the lines of:

All paralleled panel setups show an output drop disproportionately higher than the percentage of partial shading.

If you made no such claim, then speaking for myself, I was not disagreeing with you.

Perhaps the fact that all higher-priced quality panels have diodes built into their design,

combined with the fact that many members here buy their panels based on price from Amazon, Home Depot etc.

accounts for discrepancies (if any) between what we observe? Not "we" as in "you and me", but any members

I do know that serial connected panels show that sort of disproportionate drop to a much greater degree.

As stated, with the right controller anyone can test empirically which configuration suits their situation.

And using only one appropriately chosen panel per controller eliminates the issue.

Also, many people do not worry much about shade's effects.

 

[highdesertranger]

I thought all panels now-a-days have a blocking diode built in. highdesertranger

 

[Weight]

I only know my test results on my system. Your system might be different.

 

[AJ452]

The panels I have been looking at do in fact have diodes already built in. I appreciate all the input, folks!