EDIT - Issue resolved (sort of) its a firmware issue. More info in post below - https://www.solarpaneltalk.com/forum...966#post421966
Hi all,
Ive had this setup for about a year. 15 Panasonic panels with Enphase microinverters. Today I noticed that one panel was generating a bit less than others for the day. I went back day by day and noticed the same pattern going back 3 months to early October.
I looked at the timelapse of generation, and it appears that this one panel dips to about half of what panels around it are outputting for anywhere between 15 to 30 minutes. Always around the same time of day (around 10am). After the dip the panel goes back in line with other panels. On several days a dip happened in the afternoon as well.
First instinct was shadows. But it cant be, this panel is surrounded by other panels that dont have this issue. A shadow would have to be cast from the southern direction as thats the only place that has trees around the house (and even their shadows never reach the array, not even close), this panel is on the north side of the array, so if it got a shadow, everything under it would have shadow as well, but those panels are fine. I would also expect a shadow to change its location over course of 3 months and hit other panels. And as far as cloud shadows, this seems way too consistent for that.
I climbed on the roof to check it out, there was a splatter of bird poop on this panel. I cleaned it off and will see how it does tomorrow. But can bird poop do this? Like specific angle of the sun or something at that time of day cause the generation to drop in half, then recover to full? The splatter was about the size of half of one cell. Im dubious for one major reason, behavior is since October, we have had at least 2 rains since then. I dont think the bird poop is 3 months old. I was able to wash it off without scrubbing with a hose in 1 minute, I dont think sustained 6 hour rain would have had an issue.
Here is a video of the generation timelapse, 3 random weeks between October and today (but every day is like this). Sorry for recording on phone off screen, I dont have a good way to record a video of the screen right now. Time of day is bottom left, dates top left, bottom of the screen is south. Panel in question is top row 2nd from the right.
Has anyone seen anything like this before? Is the panel or microinverter going bad? What could this behavior signify? Also a technical question. When using a single inverter all panels can be brought down to the generation of the weakest one. Does each panel internally work the same way? Like if a cell is completely blocked off on a panel, does generation of all other cells also go down to whatever the lowest cell generates?
Here is a comparison of the problematic panel's graphs vs the panels to either side of it:
https://imgur.com/IwVvizI
IwVvizI.png
Hi all,
Ive had this setup for about a year. 15 Panasonic panels with Enphase microinverters. Today I noticed that one panel was generating a bit less than others for the day. I went back day by day and noticed the same pattern going back 3 months to early October.
I looked at the timelapse of generation, and it appears that this one panel dips to about half of what panels around it are outputting for anywhere between 15 to 30 minutes. Always around the same time of day (around 10am). After the dip the panel goes back in line with other panels. On several days a dip happened in the afternoon as well.
First instinct was shadows. But it cant be, this panel is surrounded by other panels that dont have this issue. A shadow would have to be cast from the southern direction as thats the only place that has trees around the house (and even their shadows never reach the array, not even close), this panel is on the north side of the array, so if it got a shadow, everything under it would have shadow as well, but those panels are fine. I would also expect a shadow to change its location over course of 3 months and hit other panels. And as far as cloud shadows, this seems way too consistent for that.
I climbed on the roof to check it out, there was a splatter of bird poop on this panel. I cleaned it off and will see how it does tomorrow. But can bird poop do this? Like specific angle of the sun or something at that time of day cause the generation to drop in half, then recover to full? The splatter was about the size of half of one cell. Im dubious for one major reason, behavior is since October, we have had at least 2 rains since then. I dont think the bird poop is 3 months old. I was able to wash it off without scrubbing with a hose in 1 minute, I dont think sustained 6 hour rain would have had an issue.
Here is a video of the generation timelapse, 3 random weeks between October and today (but every day is like this). Sorry for recording on phone off screen, I dont have a good way to record a video of the screen right now. Time of day is bottom left, dates top left, bottom of the screen is south. Panel in question is top row 2nd from the right.
Has anyone seen anything like this before? Is the panel or microinverter going bad? What could this behavior signify? Also a technical question. When using a single inverter all panels can be brought down to the generation of the weakest one. Does each panel internally work the same way? Like if a cell is completely blocked off on a panel, does generation of all other cells also go down to whatever the lowest cell generates?
Here is a comparison of the problematic panel's graphs vs the panels to either side of it:
https://imgur.com/IwVvizI
IwVvizI.png
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