Hi guys, I really need help please.

Solar Panels: x16 JA Solar 545w; and x2 Canadian Solar 405w Super High Power Mono PERC HiKU. I had this panels installed in may, production was around 6.7kw on sunny day whe 16 JA panels were connected to solis invertor, as soon as 2 canadian panels was connected production will not go over 4.5 kw on sunny day. I am really annoyed by that. Is there any chance that those 2 panels are source of the problem? I hope that inverter doesn't read canadian panels 405w instead JA 545w?I rather have installers back and disconnecting those 2 and have them as decor on roof instead having drop in production. I would really appreciate your advice please. Also what I should get from this system on sunny day as I think there might by something wrong. I am keep on checking on app and inverter when is full sun on them, there is no dirt or shading on them, but I can't go over 4.7kw which is bit shame as it cost me £19000 including 2 pylontech 4.8kw batteries

 

Thank you

Edited September 30, 20232 yr by Miroslav Hrib

 

Is there any chance that those 2 panels are source of the problem?

Very likely if you have reduced output since they were added, but we would need to know how they are wired and set up. Are they all wired in series or some in parallel? Are they all facing the same direction and angle or were the new panels added in a different direction. If panels are in series and facing a different angle they will only provide what the lowest performing panel can. The new panels are also lower wattage so if in series they will be pulling down the other 16 to their spec.

If the panels are in series you will have added 2x405W (810W), but reduced the rest by 16x140W (2240W), therefore reducing the total by 1430W... this is a very rough calculation, but would explain the overall loss in production, it could be more accurate with the Vmp and Imp of the panels. The rest could be due to other factors like orientation of panels, lower sun in autumn etc.

 

Hi guys, I really need help please.

Solar Panels: x16 JA Solar 545w; and x2 Canadian Solar 405w Super High Power Mono PERC HiKU. I had this panels installed in may, production was around 6.7kw on sunny day whe 16 JA panels were connected to solis invertor, as soon as 2 canadian panels was connected production will not go over 4.5 kw on sunny day. I am really annoyed by that. Is there any chance that those 2 panels are source of the problem? I rather have installers back and disconnecting those 2 and have them as decor on roof instead having drop in production. I would really appreciate your advice please. Also what I should get from this system on sunny day as I think there might by something wrong. I am keep on checking on app and inverter when is full sun on them, there is no dirt or shading on them, but I can't go over 4.7kw which is bit shame as it cost me £19000 including 2 pylontech 4.8kw batteries

 

Thank you

Repeating some of the above. There is every chance that the 405W Canadian Solar panel are part of the problem, but it might not be the only issue. The charge rate of your batteries could be the other factor. I'm saying this without knowing the full layout of your system, but let's start with the panels.

The JA Solar panels produce maximum power at around 13.04A current, while the Canadian solar produce peak power at 10.42A. You can verify these Imp value on your panel's label, I'm just going on a google search. What it indicates, though, is, if you've got the panels in series, you will be throttling the 545W panels to around 80% of its peak capability. 

The second issue depends on your location and time of year. Since you say you paid in pounds, that' the UK, in May, so you are comparing your late Spring generation to mid-late autumn generation which should be less. I think you should check an online calculator like the pvwatts.nrel site to judge what you should be generating for your location and time of year.

Last thing, your two Pylontech batteries have a combined charge rate of 100A, or around 5kw. If you are not running any other loads, chances are your inverter is just producing what it can dump into the batteries at that time.

those 2 marked red panels are canadian, I am saying that as soon as installers realized that panels are to big in size because of chimney and boiler pipe they decided to install 2 smaller canadian panels later on and problems started so I think that might be the problem. its south facing garden roof on sun most of the day no trees etc. Installers didn't measur roof properly they came with 18 ja panels, but because of chimney and pipe they realized they are to big, bit unproffesional but I need to solve this issue asap. 

Edited September 30, 20232 yr by Miroslav Hrib

This raises another problem of shading, which is that you seem to have shadows falling from the chimneys onto the top row of panels, which will further limit generation on those panels, not only on the shaded panel, but on all the panels in that string.

Something to check. I suspect that the top string of 9 panels are supplying a separate MPPT compared to the lower string. And it's the top string that's got all the problematic panels, the 405W panels, as well as the shading falling over the 545W panels in that string. The lower string looks to be free of issues. Can you find a screen on the inverter showing the generation per MPPT? Or else how are your strings configured?

Good replies already provided. As you have found yourself the 2 x Canadians are throttling all your panels. The easiest fix will be to have the Canadians removed to remove the throttle. Not a major job.The chimneys will be another problem and a bigger task to overcome.

Once inverter name and model is provided I am sure we can try and help with the shade from the chimney side. Also if you can provide sketches of where the shade is during different times of the day or the actual roff direction where the panels are fitted and if other portions of roof is available or the size of the roof towards the left in the picture. Coordinates close by would help without providing the exact lo0cation.