Tesla replaced my MCI units because of poor production in the winter, but now it's much worse.

[Thomias]

I have a 15.1kW Solar Roof that was powered on March 1, 2021 in a West suburb of Chicago. My peak production in my first summer was about 13+kWh and I was able to store some credit for winter.
Once winter hit, my production was virtually nothing and I ate through my credits before December.
In February 2022, Tesla came out and replaced the MCI units to help produce more energy with less direct sunlight.
This summer my peak energy production dropped to about 10kWh from 13+, and I barely produced any additional credit due to this.
Now I am getting Sunny days in the end of September with 0 production now.

Has anyone else had a similar experience? Or did Tesla just goof on my install plan by not recognizing the larger home just south of my house?
I find it very difficult to get any direct answers from anyone there at all.

I wonder if I am alone with this Solar Roof experience. I have not even mentioned the other issues I have had during and after install in addition to this ongoing issue, because I am not here to bash Tesla. I knew there can be some issue being a newer company with new technologies, but this is a bit extreme.

Thanks all, I hope to hear some of your stories and experiences. Perhaps we can come up with a solutions as well.

 

[CrazyRabbit]

Edit: So you have a lot of shading, is the large home new/

I have a 17.9 system and produce around 12.5. Your system seems normal

 

[trautmane2]

Has anyone else had a similar experience? Or did Tesla just goof on my install plan by not recognizing the larger home just south of my house?
I find it very difficult to get any direct answers from anyone there at all.

Yes - I have had a similar experience and have written about here:
concerned inverter change won't solve production problem

It is interesting that you mention the possibility of shading from your neighbor's house as something Tesla might have missed in their original design/production estimate. My neighbor's home shades my east facing roof and might be contributing to my roof's reduced production.

Are you really getting 0 production from a south facing roof in September?
That sounds bad.

 

[CrazyRabbit]

Would be worth a thousand words to see a google maps view.

 

[Thomias]

Glad to see some discussion here, I had notifications going to junk and didn't notice... Sorry.
Neighbors house is over 15 years old, so it's definitely something that was missed during design.
Considering I was getting peak 13kW before the MCI replacement, I do not believe 10kWh is normal, and now overal production is very low in comparison to my first year where I had a few system outages even. :/

 

[Thomias]

Something is definitely wrong, cause I am not getting any shade on the roof yet, but producing nothing.
Attached a south roof photo at noon today...clear skies and 0 production.
Inverters are not faulting either, so just odd. 0 production every day in the last 11 days with the exception for last Thursday and Monday with somewhat normal production at about 30kWh total per day.
Technically, the shading from the neighbors house should hit hard in the next couple of weeks, so I attached a photo from the north to show the house behind mine as well.

 

[trautmane2]

Something is definitely wrong, cause I am not getting any shade on the roof yet, but producing nothing.

I agree - have you connected to your inverter to start debugging the source of the problem?

Connecting to Tesla Solar Inverter | Tesla Support

Tesla inverter viewing string data

 

[Thomias]

I agree - have you connected to your inverter to start debugging the source of the problem?

Connecting to Tesla Solar Inverter | Tesla Support

Tesla inverter viewing string data

They are Delta Inverters, I do not believe I can access these at all.

 

[Thomias]

Edit: So you have a lot of shading, is the large home new/

I have a 17.9 system and produce around 12.5. Your system seems normal

Thanks for the info. Is your roof multiple levels and angles?
My roof gets hit all at once, so I get all panels active at the same time and high peak because of this. I posted some photos to clarify as well.

 

[Redhill_qik]

Would be worth a thousand words to see a google maps view.

There street level pictures that were posted weren't scrubbed, so here is the google maps view of the OP's house. Some shading from the house to the south which will be worse in the winter, but larger trees to the west that will reduce production in the afternoon. These may have grown taller year-to-year.

@tpapadopoulos Please post your panel layout plan that Tesla gave you for your installation with the PV tile allocation between the north and south roofs. Also, are you really seeing 0 kWh of production with sunny weather? If you are then this is a system fault and you should be talking with Tesla solar support and they can look into the details and send a tech out if needed.

 

[dareed1]

They are Delta Inverters, I do not believe I can access these at all.

Use the instructions in the first paragraph of this post (and following posts) to get up to 10 days of history of string voltages and currents. In my solar panel system, I can also check the connection status of the MCIs.

 

[trautmane2]

They are Delta Inverters, I do not believe I can access these at all.

Oh - sorry I thought you already had Tesla inverters.

As @dareed1 states, you can use the M Professional app to access your Delta inverter.
Once you're connected and logged-in, click Menu (upper right) and Stats or History (can't remember).
I could only get the stat charts to populate if I connected in the morning when the sun was up - never bothered to figure out why it didn't work at other times.
All of the graphs I posted here came from M Professional.

 

[Thomias]

Thank you, seems I tried using that app in the past. I will try it again now.
I also have a Tesla tech out here for this 0 production issue, nothing they can do right now about the poor production for whatever reason.
This is the 4th time I've lost production due to the inverters in the 1.5 year life of my system.
Hope after today that I can access them to resolve the error or maybe have them replaced...

Keep you posted in a few hours.

 

[Thomias]

Tesla/Delta claim both inverters failed, error: Phase Locked-Loop Failed.
Waiting again to find out when they can be replaced.

M professional worked, I can access the inverters now to see data. Thanks Trautmane2 and Dareed1.

 

[Thomias]

Still waiting on Tesla to let me know when they will replace Inverters.
I went ahead and started looking into all the settings in my M8-TL-US Delta Inverters using the M professional App and realized that Inverter 1 is set to Utility code IEEE-1547, however Inverter 2 is set to IEEE-1547A.
Would that not cause a Phase-Locked Loop error almost all the time? How can the phase sync if there is a slight configuration difference between Inverter 1 and 2?

 

[trautmane2]

I have no idea about the differing utility codes. It will be interesting to see if fixing your inverters will involve replacement with Delta or Tesla inverters. Based upon discussions with the crew currently working on my roof, I would not be surprised if they opted to switch to Tesla inverters in the hope of reducing/simplifying future maintenance. However, switching from Delta to Tesla has been a big job for the crew working on my roof: 4 full work days over 8 calendar days so far. The difficult piece has been replacement of all the MCIs.

 

[Thomias]

Tech was good enough to come out a replace Inverter 1 with one they had in stock. Was nice to have it done so quickly.
It only worked the rest of that day, and now I have the Phase-Locked Loop failed.

 

[Thomias]

Disconnected service so that I can go off grid and the inverters can produce and recharge my batteries. I was right, it works without grid, so for some reason it's just not able to match supplied service phase. So my production issue has now become even more strange with this added error causing 0 production.
Fun stuff here. :/

 

[buckets0fun]

Have CTs ever been replaced within your system?

 

[Thomias]

Have CTs ever been replaced within your system?

No, not to my knowledge.