Sudden drop of production on sunny day

[houser2021]

There seems to be erratic power reporting to Gateway?

Can you clarify what you mean? Is the tesla inverter having trouble communicating to my wifi?

 

[sorka]

I called the service adviser and he told me since I do not have PTO and not officially turn on the system now, the reporting from the app may be wrong. He asked me to wait until PTO and check again. I guess I will have to wait until PTO. Not sure if PTO and some official activation will make a difference at all.

If I had your levels of production with that size system with no shading on clear days, I would never have paid Tesla until they fixed it. I had an issue with the the powerwalls output frequency causing my HA switches to all go nuts. Tesla fixed this this long before I was ever granted PTO.

Also, if PG&E knew there was a problem with the system, they'd never grant PTO. Tesla needs to fix this before PTO is granted, not after. You're allowed to test the system prior to PTO to work out any problems. Tesla can't just say you need to get PTO first.

 

[charlesj]

Can you clarify what you mean? Is the tesla inverter having trouble communicating to my wifi?

I would think that the solar production side, reporting power output is inconsistent someplace or it could be wire connection issues that comes and goes away.

Are you able to go and look at your power company meter when you notice this, if it is readings of drastic changes going to the grid if it is already going to the grid?
I would also contact Tesla, tell them the weather is clear and sunny, this should not be happening.

I had issues when Tesla added a current sensor at my solar breaker but the antenna of the sensor was inside a power panel, all steel. It worked erratically at times. I should think so. i wouldn't encase my wi-fi in a steel box and expect good operation.

A tech came out and relocated the antenna outside the steel box; almost flawless now.

 

[houser2021]

I would think that the solar production side, reporting power output is inconsistent someplace or it could be wire connection issues that comes and goes away.

Are you able to go and look at your power company meter when you notice this, if it is readings of drastic changes going to the grid if it is already going to the grid?
I would also contact Tesla, tell them the weather is clear and sunny, this should not be happening.

I had issues when Tesla added a current sensor at my solar breaker but the antenna of the sensor was inside a power panel, all steel. It worked erratically at times. I should think so. i wouldn't encase my wi-fi in a steel box and expect good operation.

A tech came out and relocated the antenna outside the steel box; almost flawless now.

thanks for the details. I have a neurio inside my panel but the antenna is not sticking out. I’ll let them know to fix this. Although I thought that was for measuring consumption only

 

[dareed1]

I think I'm having the same problem. 8.16kW system installed last month with Tesla inverter and 2 Powerwalls on south facing roof, no shade or obsructions. Today no clouds, temp is 77F, at peak 12:30pm system maxed out at 3.8kW. Been maxing out at 3.8-4kW since beginning of month. Not enough power generation to fully charge PW every day.

Focus on this issue only when talking to Tesla. The Powerwall charging is only slightly relevant; it shows that this is not a monitoring problem. Apparently the system is only generating roughly half power. Two obvious possibilities: 1) One of the strings (12 panels) is not connected or its MPPT channel is not working, or 2) the two strings are Y-jumpered (connected in parallel) and fed to only one MPPT channel. If 1) the graph of production versus time will be a bell-like curve. If 2) the graph will be flat topped for perhaps 3 hours. (On sunny days, of course.)

I had an issue like this with our Delta M8 inverter, and it was necessary to be be persistent with Tesla. The first and second responses from Tesla were A) it's working fine, and then B) we'll have to wait a year to see if it meets production targets. I kept hammering and eventually got the support person to talk to a tech, who could immediately see that the system was malfunctioning.

BTW, our system got PTO on December 18, 2020, and as of April 12, the system is finally almost right. I could have speeded things up a little. After a while I realized that waiting for Tesla to call me back doesn't work. My advice is to always stay on the phone until a live person responds.

 

[charlesj]

thanks for the details. I have a neurio inside my panel but the antenna is not sticking out. I’ll let them know to fix this. Although I thought that was for measuring consumption only

Hopefully that is you issue as well. My subpanel on the 2nd story is where the sensor is and Gateway on the far side of the garage, a good distance.
I was questioning the antenna at the time but installer said it was fine.
Mine was easy to fix as I had an unused knockout with a plug that was just lifted out and the new tech attached the antenna and wire to a fitting that went into that hole. Now the antenna is in the wall cavity with just the sheetrock and other walls in the way. It works.

Depending on your setup but the Gateway gets info from solar, battery, and most likely from the main cable in the Gateway then calculates and integrates usage.

 

[taphil]

Focus on this issue only when talking to Tesla. The Powerwall charging is only slightly relevant; it shows that this is not a monitoring problem. Apparently the system is only generating roughly half power. Two obvious possibilities: 1) One of the strings (12 panels) is not connected or its MPPT channel is not working, or 2) the two strings are Y-jumpered (connected in parallel) and fed to only one MPPT channel. If 1) the graph of production versus time will be a bell-like curve. If 2) the graph will be flat topped for perhaps 3 hours. (On sunny days, of course.)

Thanks for the input. I started a new thread specifically about my system to get some analysis.

New solar and Powerwall install, low production?

Hi, I'd appreciate some analysis on my new installation and if there's a problem with it. I got a 8.16kW 24 panel system plus 2 Powerwalls installed in March. Located about 20 miles east of Downtown Los Angeles. Telsa Gateway 2, Tesla 7.6kW inverter, and the two Powerwalls are installed in...

teslamotorsclub.com

 

[EVTomorrow]

Just a quick follow up everyone: after Tesla officially activated the system, the sudden drop never occurred. So what the advisor told me was actually true: I had to wait for system activation to test it out.