Number of Strings

[GHTech]

Greetings,

I have a 8.16 kW PV, 2 PW system and a SE7600H-US Inverter installed Sep. 2020. It looks like I have only 1 string of 24 panels. I have panels on 3 different roof planes (16, 5 and 3 panels). Is this okay?

Thanks,

GHTech

 

[Ampster]

How is your production? What time period is that ouput data from? Does that picture represent your three planes? How was it in September?
There is an online tool available at pvwatts.org that might give you a way to model a typical system in your location to benchmark against your historical output.

 

[GHTech]

How is your production? What time period is that ouput data from? Does that picture represent your three planes? How was it in September?
There is an online tool available at pvwatts.org that might give you a way to model a typical system in your location to benchmark against your historical output.

The numbers i am getting are better than the pvwatts calculator. I did the 3 directions. I was just not sure if they should have used 2 strings, or it does not matter.

 

[Ampster]

The details would not matter to me if the system was performing.

 

[Vines]

Greetings,

I have a 8.16 kW PV, 2 PW system and a SE7600H-US Inverter installed Sep. 2020. It looks like I have only 1 string of 24 panels. I have panels on 3 different roof planes (16, 5 and 3 panels). Is this okay?

Thanks,

GHTech

From what you said and showed I don't have any concerns. All strings are parallel within a SE inverter anyway. Its the optimizers that do the work, rather than individual MPPT trackers.

 

[GHTech]

From what you said and showed I don't have any concerns. All strings are parallel within a SE inverter anyway. Its the optimizers that do the work, rather than individual MPPT trackers.

Hi Vines,

The reason that I asked is that I see others mention that a certain number of panels should be the maximum per string. I think that recently someone mentioned 16. I believe that my inverter can do 2 strings, and was wondering why they did not split the panels to the 2 strings. If it does not make a difference, that is fine.

Regards,

GHTech

 

[Vines]

Pretty sure Tesla is using double optimizers these days, so longer strings are possible. If you aren't noticing a production issue, don't worry.

Shorter strings are worse than long ones as then you can lose target voltage.

 

[GHTech]

Pretty sure Tesla is using double optimizers these days, so longer strings are possible. If you aren't noticing a production issue, don't worry.

Shorter strings are worse than long ones as then you can lose target voltage.

Production numbers are higher than pvwatts numbers. I am not complaining.

 

[DanB2]

My SE app shows all 33 panels on one string. I had a tech out for a different issue and asked him about it. He said that in fact there are three physical strings but for whatever reason it was mapped as one string when commissioned. All panels produce well so I am guessing it’s fine.

 

[nwdiver]

My SE app shows all 33 panels on one string. I had a tech out for a different issue and asked him about it. He said that in fact there are three physical strings but for whatever reason it was mapped as one string when commissioned. All panels produce well so I am guessing it’s fine.

I installed a SE system and never could figure out how to delineate strings on the overview. There are 3 physical strings but it's displayed as one. If you're interested in determining how many strings you have take your optimizer voltage and divide it into you inverter dc voltage (usually ~390v). That gives you the number of panels in that string assuming they're all producing roughly the same power.

But SE strings shouldn't have >6kW in them. If your optimizer voltage is <17v I would call your installer and have them fix it....