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Topic: Solar & Shade? and Controller brand? (Read 1 time) previous topic - next topic
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Solar & Shade? and Controller brand?
Yahoo Message Number: 23370
My thinking had been that if the solar panel was 10 % covered with a shadow that would cause about a 10 % reduction in output.
Is that correct?

A recent post seemed to say that a little bit of shadow caused big reduction in output.

Yesterday, I went to the amsolar website and read about the good features of the Heliotrope brand solar charge controller.
Among the features mentioned was adjusting the charge according to the temperature of the batteries.
What brand solar charge controller does LD install in 2003 model? Does that have some sort of temperature compensation? Is there a temperature sensor in battery compartment?

Ken, Patty, and little Stephanie in San Diego
Re: Solar & Shade? and Controller brand?
Reply #1 –
Yahoo Message Number: 23371
Quote
What brand solar charge controller does LD install in 2003 model?
Lazy Daze uses a Heloitrope Model RV-30 Controller for the Solar Panels.

JC
Re: Solar & Shade? and Controller brand?
Reply #2 –
Yahoo Message Number: 23384
Quote
My thinking had been that if the solar panel was 10 % covered with a shadow that would cause about a 10 % reduction in output.
Is that correct?
A leaf shadow on your panel can disable its output. A typical panel consists of 36 low-voltage cells wired in series (daisy-chained) to produce 17 Volts. The current developed by the weakest cell is all the current available from the entire panel. So, if you shadow 80% of just one cell, your maximum current will be 20% of full output.
Bypass diodes incorporated to prevent overheating of cells do not solve this problem. This is why more small panels wired in parallel is better than one large panel. If you want to depend on solar charging, avoid shade like the plague. If you can't avoid shade, conserve use of electricity.

Steve
2004 FL
2013 Honda Fit
Re: Solar & Shade? and Controller brand?
Reply #3 –
Yahoo Message Number: 23387
"A leaf shadow on your panel can disable its output."
 That's a pretty extreme statement, Steve, and my experience doesn't bear it out. I have four panels, I often park under trees, and I still get plenty of juice. In fact, my A/C shroud overhangs one of the panels by an inch. By your rule of thumb that panel should be dead as a doornail, but it certainly doesn't act that way!

Now admittedly I haven't taken indvidual panel voltage/current measurements--I don't have an easy way to do so without ripping apart my wiring, which of course I'm not going to do. So I don't have numbers on what's going on when a single leaf shades a panel. But that situation's the rule rather then the exception with Gertie, yet it doesn't seem to make much difference.
 Oh, I don't doubt that output is reduced to some extent...but my experience simply doesn't jibe with the all-or-nothing nature of your statement. If what you say were true, I'd almost never get any charge out of my panels, and believe me, I get plenty!

Andy Baird :-)
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: Solar & Shade? and Controller brand?
Reply #4 –
Yahoo Message Number: 23395
Quote
Now admittedly I haven't taken indvidual panel voltage/current measurements--I don't have an easy way to do so without ripping
apart my

Quote
wiring, which of course I'm not going to do. So I don't have
numbers on what's
 
Quote
going on when a single leaf shades a panel. But that situation's
the rule rather
 
Quote
then the exception with Gertie, yet it doesn't seem to make much
difference.

Andy, the saving grace is your 4 panels, and this is why it is recommended to go with multiple panels. You could do the experiment if you wanted, by covering three panels and then selectively shading spots on the fourth. I did a pretty extensive battery of tests on ours before installing them, and the effect is sobering.

Steve
2004 FL
2013 Honda Fit
 
Re: Solar & Shade? and Controller brand?
Reply #5 –
Yahoo Message Number: 23397
"You could do the experiment if you wanted, by covering three panels and then selectively shading spots on the fourth."
 Good point, Steve! Maybe someday I'll get around to doing it, and gather some hard data on this.

Andy Baird :-)
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"