Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Very low solar generation - 26k System - 3 Inverter - 3 PW - Less power on sunny days

This site may earn commission on affiliate links.
I’m far from an expert in this, but according to your drawings, it seems to me that strings 3 and 13 should be swapped so that each inverter is fed from strings with similar azimuths.

Your drawings show inverter 1 handling your SW facing panels with the exception of string 3, which is NW. Inverter 3 is handling the NW facing panels with the exception of string 13, which is SW. Inverter 2 is handling the SE panels and appears to function normally.

I’d try to double check the wiring to see if this is actually the case, or what.
 
I’m far from an expert in this, but according to your drawings, it seems to me that strings 3 and 13 should be swapped so that each inverter is fed from strings with similar azimuths.

Your drawings show inverter 1 handling your SW facing panels with the exception of string 3, which is NW. Inverter 3 is handling the NW facing panels with the exception of string 13, which is SW. Inverter 2 is handling the SE panels and appears to function normally.

I’d try to double check the wiring to see if this is actually the case, or what.
Thanks ! I’ll take a look. I know trees aren’t helping but I do think the strings are not configured correctly. I’ll take a look when I get home and report back

One question I have does the entire inverter matter for the direction / parallel lines or is it just the strings going to the mppt in each line of the inverter
 
I’m far from an expert in this, but according to your drawings, it seems to me that strings 3 and 13 should be swapped so that each inverter is fed from strings with similar azimuths.

Your drawings show inverter 1 handling your SW facing panels with the exception of string 3, which is NW. Inverter 3 is handling the NW facing panels with the exception of string 13, which is SW. Inverter 2 is handling the SE panels and appears to function normally.

I’d try to double check the wiring to see if this is actually the case, or what.
So i looked into it alittle more in depth tonight.

Inverter 2 does seem to be the best overall and most accurate.
That has a total of 6 strings into 3 mppt all facing north east 49 azimuth.

Inverter 1 has 5 total strings 4 mppt
1 mppt has 15 panels 229 azimuth
1 mppt has 8 panels 137 azimuth
1 mppt has 24 panels 227 azimuth
1 mppt has 2 strings parallel 2x28 (56) panels 227 azimuth


Inverter 3 has 4 total strings into 2 mppt
1 mppt has 2 strings parallel (not sure) shows as each 1x30 (60 total) panels
- 1 string is 227 azimuth
- 1 string is 317 azimuth
1 mppt has 2 strings parallel 2x20 (40 total) panels both are 317 azimuth


It looks like they are combining strings in the roof as well as jumping them. Im not really sure how it works based on the diagrams. It does look like all the combined strings match amount of panels. I take it thats important based on the warning in the inverter box that says they must be same amount of panels?

Inverter 3 seems a bit odd , looking at the diagram and my info above , the picture seems to indicate that there are only 3 mppt with a jumper? Similar to inverter 2?
 
Just alittle update,

I am now only producing 12.5 kwh a day and peaking around 2.8kw. Seems way to low for my system. I have a ticket out with tesla and they will be getting back to me soon. My neurino keeps disconnecting / beeping now as well. Hopefully they find something.
Do you have any update, I am seeing a similar problem where a rainy/cloudy day would produce more than a sunny day.
 
Just alittle update,

I am now only producing 12.5 kwh a day and peaking around 2.8kw. Seems way to low for my system. I have a ticket out with tesla and they will be getting back to me soon. My neurino keeps disconnecting / beeping now as well. Hopefully they find something.
Did they get back to you? I am having the exact same issue. Production is so low, but weirdly rainy/cloudy days are better than sunny days
 
Did they get back to you? I am having the exact same issue. Production is so low, but weirdly rainy/cloudy days are better than sunny days

Hello, so I waited about 30 days for tesla to tell me they updated my neurino / changed my hz for my battery backups and completely ignore the rest of my request and closed it.

My neurino is still beeping / doing its chime randomly and frequently as if its not connecting or something. The solar generation is as inconsistent as ever now.

The sunny / cloudy thing is as bad as ever. For instance these two days show what I’m talking about. (Attached pics)
One shows a fully sunny day , im talking clear skys all day. I maxed out at 1.8 kw and generated 8.9 kwh that day.

The second pic shows a fully cloudy day almost 0 sun and even some rain. Topped out at 4.6kW and generated 19.9 kWh for the day.

Clearly something isnt right. Now that we got snow, and alittle remains on the roof, the last 3 days i have generated 4.3 kwh , 5.1 kwh, and 6.0 kwh. (all sunny days). The odd thing is i have almost no snow on the roof as it all slid off but the only spots where theres still some are the heavily shaded areas, Almost kind of proves my theory that those areas are causing some significant issues w/ my generation. Perhaps parallel lines.

So I put another request in to tesla to do a whole house in person review of my system. There service has been absolutely atrocious and for the amount of money I paid for this system I'm starting to get aggravated w/ them. They "escalated" my request but said it will take 2 weeks due to holidays so ill update when that happens.
 

Attachments

  • 4071EB46-A540-41D1-B12B-ABE3A87BAF86.png
    4071EB46-A540-41D1-B12B-ABE3A87BAF86.png
    143.2 KB · Views: 73
  • EB27773E-5094-4AFF-8CB4-6B13CD3699C4.png
    EB27773E-5094-4AFF-8CB4-6B13CD3699C4.png
    143.5 KB · Views: 53
Sorry to hear that, I know the feeling as I am having a similar issue, although my system is smaller. At cloudy days my peak and total production are much better than full sunny days. But even at these cloudy days, I am still generating about 7-8kw total per day, which is way low. I contacted them multiple times per chat with no meaningful response, called them recently and the agent opened a case with 2nd tear support, will update you if they get back to me.
 
So tesla finally got back to me and gave me a nice Christmas present. Essentially told me they did a remote verification on my wiring lol and everything is fine. Production is working as expected. Yet my neurino is still beeping / not connecting for one. So bare minimum , clearly its not right. Yesterday full sun I topped out at 1.7 KW and generated 8.1 kwh. They closed my request which is my 3rd one and have not responded since. Im starting to lose my patience and not sure what the next course of action is.
 
Sorry to hear that, I know the feeling as I am having a similar issue, although my system is smaller. At cloudy days my peak and total production are much better than full sunny days. But even at these cloudy days, I am still generating about 7-8kw total per day, which is way low. I contacted them multiple times per chat with no meaningful response, called them recently and the agent opened a case with 2nd tear support, will update you if they get back to me.
Hi I'm also having similar issue with my 7.2KW system which recently received PTO. Did you get any resolution after your post on 22nd December? Please share..
 
They closed my ticket soon after saying there is nothing wrong with my system as it is peaking at almost 4.8kw at noon for few minutes, it stays around 3.5KW for 3 hours now. Since we are in Feb and the sun gets out a little longer and at a higher angle, I am producing around 20KWh per day on my 6kw system. I also asked HOA to trim the high pine trees behind my property which I think will help with production as my house is below street level and surrounded by trees. I would suggest to keep an eye on your instant production level between 11am-12pm, and see if you can get around 5-6kw on your 7.2 system, if so then it might be an issue with shade.
 
They closed my ticket soon after saying there is nothing wrong with my system as it is peaking at almost 4.8kw at noon for few minutes, it stays around 3.5KW for 3 hours now. Since we are in Feb and the sun gets out a little longer and at a higher angle, I am producing around 20KWh per day on my 6kw system. I also asked HOA to trim the high pine trees behind my property which I think will help with production as my house is below street level and surrounded by trees. I would suggest to keep an eye on your instant production level between 11am-12pm, and see if you can get around 5-6kw on your 7.2 system, if so then it might be an issue with shade.
Not sure how much shading you get or panel orientation but some of your numbers got me curios. :)
I have a smallish system that once peaked at 3.82 kW in May 2012. This system peaked at 3kW today and this past Wednesday I generated 19.9 kWh of energy. I do have a small shading issue later in the afternoon, starting about 3 PM. panels face about 190 degrees.
 
They closed my ticket soon after saying there is nothing wrong with my system as it is peaking at almost 4.8kw at noon for few minutes, it stays around 3.5KW for 3 hours now. Since we are in Feb and the sun gets out a little longer and at a higher angle, I am producing around 20KWh per day on my 6kw system. I also asked HOA to trim the high pine trees behind my property which I think will help with production as my house is below street level and surrounded by trees. I would suggest to keep an eye on your instant production level between 11am-12pm, and see if you can get around 5-6kw on your 7.2 system, if so then it might be an issue with shade.
They closed my ticket as well. I do see only one peak a day where it generated 15.6 kW. Rest of the days is close to 12 kW only. I have three zone MP1 - with 5.6 kW @ 34 Pitch and 355 Azimuth. MP2 with .8kW @23 pitch and 265 Azimuth. The third one MP3 is of .8kW@ 23 pitch and 85 Azimuth. When I tallied the power generation with pvWatts, then it seems in line with Tesla generation. So I'm not sure whether its problem or its generating as designed.