Panel Performance Issue?

[Gavin A]

To me that looks from the outputs like they've run it in a string of 10 panels and a string of 6 panels, though the voltages more suggest 11 and 5 - is the bigger portion of the array shaded at all?

Both configurations would be within the range of the inverter, though I doubt it'd be operating very efficiently as it's massively over specced, which could partially explain the lower outputs.

Either way, it's clear that it's not 8 panels on each.

I'm assuming the voltage readings were taken from the inverter when it was operating?

 

[lennyg]

To me that looks from the outputs like they've run it in a string of 10 panels and a string of 6 panels, though the voltages more suggest 11 and 5 - is the bigger portion of the array shaded at all?

Both configurations would be within the range of the inverter, though I doubt it'd be operating very efficiently as it's massively over specced, which could partially explain the lower outputs.

Either way, it's clear that it's not 8 panels on each.

I'm assuming the voltage readings were taken from the inverter when it was operating?

Thanks for your reply - the array is not shaded at all when the readings were taken - the readings were in full sun. How much overspecced is the inverter and how much am I losing because of such?

 

[moggy1968]

How much overspecced is the inverter and how much am I losing because of such?

massively overspecced. I would use a 3.6kWinverter, although opinions vary

 

[lennyg]

For those not necessarily wanting to read the whole thread, my issue is that my 4kw system with 2 strings is producing max 3kw with one string producing about 1900w and the other 1100w all in unshaded direct sunlight, with the voltage ratios being the same (roughly 2:1) The theory is that the strings are split 10/6 however....

An interesting (or maybe not) further piece of information - This morning we had a very bright morning but with diffused high cloud so the panels were receiving a lot of light but not direct sunlight. Taking readings from the inverter, both strings were performing similarly producing about 500W each and similar voltages on both strings - this seems tome to negate previous posts of the array being split 10/6 as I would expect the ratio between the strings to be the same.