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New install - does these reading look correct to you ?

7 comments started 2023-12-23 last 2023-12-31
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M
#1 Mr Neil

Hi everyone...

I have just had my old Solar array replaced with a new 16x 430w Solar panels, as yet I have not had any really sunny days to get some accurate readings.

I have 2 strings - each with 8 panels per string ( on top of each other ) and they are all on the same SSW facing roof with NO shadows at all, so I was expecting that I would generate equal power and figures per string.

Now below is what I got today.... and they don't seem to make sense... at first it string 1 seems to indicate around a 50W difference so I was thinking maybe a faulty panel on string 2 - but then string 2 seems to jump up !!!

Whats your view on this ?

I have a feeling this might actually be an issue with how the inverter is logging the data... does it log the string 1 & 2 at the exact same time or is there a time lag between the 2 ?

M
#2 Mr Neil

My next steps will be to put actual energy clamps on the wires before if hits the inverter to try and see what Voltage/Ampage is actually on each string.

But has anyone seen issues like this with older firmware maybe ?

M
#3 Mr Neil

FYI - this is how my array looks ( older panels - I now have 16 not 14 )

So you can see why I am expecting identical readings on both string as the chimney doesn't cast a show

#4 nophead

Perhaps clouds passing over? What do the graphs look like?

I wouldn't draw any conclusions until you get a clear sky sunny day. I don't know how closely solar panels are matched, especially under low light conditions. Most semiconductors have a spread in characteristics from one device to another. I don't know if that includes PV panels but it wouldn't surprise me.

#5 Watcher

I have 2 strings south facing, you can see string 2 (which is the right side of the roof looking north I.e. nearer the sun as it rises) started producing earlier than string 1. I suspect they will equal at midday and then swop over as sun heads down. Might this account for it?

#6 Watcher

EDIT
Gave it a bit more thought and went back to check a couple of full days rather than just today’s snapshot above and the result is….I am talking crap. My right string out performs my left all day, now I am worrying for no apparent reason!