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jond avatar image
jond asked

Why isn't my PV generation covering all my day loads?

I have 20 x 360w panels on my roof (one roof, facing north).


5 strings of 4. MPPT 250|100.


Why isn't the PV covering all the day loads?


ESS not feeding in. Set to about 60% state of charge for self consumption.


The multiplus II 5kva is still pulling from the battery and grid. See image below 11am:



Multiplus-IIESSVRM
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Warwick Bruce Chapman avatar image Warwick Bruce Chapman commented ·

Jon did you resolve this?

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jond avatar image jond Warwick Bruce Chapman commented ·

Not yet,


The customer feels the array should cover all day loads 20 x 360w panels. So either the system isn't generating what it should or the customer's usage is more than what the panels can handle.


See here 10:00 & 11:00 o'clock:


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3 Answers
dgnevans avatar image
dgnevans answered ·

Can you advise more on how your sertup is do you have images from your Venus. can you put up an image from vrm for the same periods for solar.

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jond avatar image jond commented ·

The clien't doesn't have a good WIFI connection at site, I only have the available images.



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Robert Riebli avatar image
Robert Riebli answered ·

Is it a 3-phase grid connection? if so, an EM24 meter is recommended so that what is drawn from the grid is correctly displayed.

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jond avatar image jond commented ·

So it could be that the PV is covering the loads, but it is displayed incorrectly? I was expecting 6000w and looks like im only getting 4000w during times loads are high with the 20 x 360w panels.


It is single phase with 2 x MPII in parallel.


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Alexandra avatar image
Alexandra answered ·

@jond

I agree that is an awesome array you should have no problem. I am running 12 x 330w and easily make 3500w continuously.

A few more questions about your setup though.

1) Do all your panels have the same orientation? For example all on one roof face facing north?

2) Are all your strings making proper contact? Do you measure the full VOC on each string when they are not plugged into the mppt?

3) The next would be settings. Have you power limited the mppt? It may sound silly but I have seen installers do that and not realise it.

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jond avatar image jond commented ·

1) Yes. One roof facing north.


2) We tested this. All seems to be fine. Voc is 47.2 per panel ... so per string (4) its around 180V & 9A and total array also 180V & 45 A


3) Where do you do this? while programming the MPPT? I'm sure we didn't limit settings here.


I was expecting around 6000w, Here is a newer photo, does this look normal for ESS system or should all the loads be covered by may array. Its winter here, around 20 to 25 degrees and very sunny.




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