Insolation too low with seconary array added

Problems
#1

I recently added a secondary array to my system and now the insolation curve seems to be too low for my system. The chart shows the correct total wattage of the system and it properly shows the panel count and wattage for the individual panels in each array, but it also shows that output today as 133% of expected. It was a nice day, but not that nice. Here is a screenshot:

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All of the days since I added the array seem to be showing too low of an insolation estimate. The system id is 6222 for anyone that wants to look at other days.

When I added the additional array, I did not decommission the old system and create a new one as recommended, because that resets the yearly graphs and I can’t see total output year to year. Instead I just edited the existing system and added the additional array. I understand that will mess up insolation estimates when I look at old data, but I wouldn’t expect it to mess up the data for days after adding the new panels.

Prior to adding the secondary array the insolation and target percentage numbers seemed reasonable all throughout the 6 years the system had run. The new panels are at the same azimuth and tilt as the original ones so I haven’t changed that part of the configuration.

Any suggestions as to how to get the insolation curve and target percentage numbers to be correct for my system? Anyone else have this issue?

#2

Hi this is quite common with a good system,mine is very similar to yours and today mine did 136%,today
see jims maxim jinkos 6.625 KW. what i did with mine was make and set my own monthly targets, in my case the extra output is because i am using Jinko maxim panels so i have 75 maxim chips in my system and one 5KW inverter, i see your system is using a mini inverter for every panel,so if you have a day like mine today withe part shade the there is a big difference between the isolation
curve and what the system will produce

#3

The insolation estimate result will be the same with a single 7.560kW array.

The secondary splits the total estimate into individual estimates for each array.

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#4

Thanks for the replies. I get that the overall estimate is the sum of the two array estimates. I was just surprised that the production was much higher than the estimate. With the original array, the estimate pretty much matched the actual production. Perhaps the new panels (and inverters) I added are really that much better than the original panels and therefore exceed the estimated insolation.

#5

This should be a good thing :slight_smile:

#6

I added are really that much better than the original panels and therefore exceed the estimated insolation.
This should be a good thing :slight_smile:

Hi yes you are right about them being better the the average, If you really need a closer to the isolation figure then you could use the NOCT rating for your panels instead of the STC you have used,this will give you a much closer to the isolation curve and also a higher efficiency to reflect this as well. :grinning: