Serial vs Parallel Solar Panel Shading
I was asked if a post in another thread if this "Serial is actually better for shading (than parallel) if that is a concern for you." was a typo. It is not a typo but panel shading is not always under...
Forum Discussion
liborko Wrong? Thanks for pointing out that I did not include the diode voltage drop in the calculations as I clearly stated in my second post from which you quoted.
My diodes have a 0.4V drop and that amount is not very significant when you consider the total 90V panel output. The voltage drop would be 0.4*7 for 7 shaded panel sections. But The point of my post is that the 2 unshaded panel portions will provide panel charging for serial.
Actually I’m surprised that you didn’t point out that for one fully shaded parallel panel would have the output from 2 panels while the serial output would have a small amount less due to the 3 conducting diodes. Ditto for 2 shaded panels. I’d rather have partial panel power available rather than less in the overall panel shading situations.
Keep in mind that the context of my post was about partial panel shading vs reduced light or overall shading of all panels.
Yes I did generalize some and my initially intention is to get us all a better understanding of panel shading. Over the years there have been many incorrect posts on this subject.
A diode failure is not a concern for me. My panels are well constructed commercial panels with oversized diodes and all diodes and wiring connections included the 10ga pigtails in the panel junction box are welded and well supported. But of course a failure could occur. Some panels have parallel diodes which improves reliability. Ie A three section panel could have 6 or more diodes. There are various pros and cons to serial vs parallel many of which have not been raised in this thread.
Please post information indicating how much power a partially shaded parallel panel will produce when in parallel with a non shaded panel as I have no personal experience. All of the internet information I’ve seen clearly indicates that the shaded panel with lower voltage will not produce any usable output.
This can get very involved when trying to understand panel technologies, light conditions, temperature, shading, costs, wiring losses and PWM vs MPPT CCs.
My objective was to provide a basic and better understanding of shading and we can all work together for a better understanding.
My diodes have a 0.4V drop and that amount is not very significant when you consider the total 90V panel output. The voltage drop would be 0.4*7 for 7 shaded panel sections. But The point of my post is that the 2 unshaded panel portions will provide panel charging for serial.
Actually I’m surprised that you didn’t point out that for one fully shaded parallel panel would have the output from 2 panels while the serial output would have a small amount less due to the 3 conducting diodes. Ditto for 2 shaded panels. I’d rather have partial panel power available rather than less in the overall panel shading situations.
Keep in mind that the context of my post was about partial panel shading vs reduced light or overall shading of all panels.
Yes I did generalize some and my initially intention is to get us all a better understanding of panel shading. Over the years there have been many incorrect posts on this subject.
A diode failure is not a concern for me. My panels are well constructed commercial panels with oversized diodes and all diodes and wiring connections included the 10ga pigtails in the panel junction box are welded and well supported. But of course a failure could occur. Some panels have parallel diodes which improves reliability. Ie A three section panel could have 6 or more diodes. There are various pros and cons to serial vs parallel many of which have not been raised in this thread.
Please post information indicating how much power a partially shaded parallel panel will produce when in parallel with a non shaded panel as I have no personal experience. All of the internet information I’ve seen clearly indicates that the shaded panel with lower voltage will not produce any usable output.
This can get very involved when trying to understand panel technologies, light conditions, temperature, shading, costs, wiring losses and PWM vs MPPT CCs.
My objective was to provide a basic and better understanding of shading and we can all work together for a better understanding.
