Panel Production Problem or Gateway Issue?

[EM CARS]

I want to start from the beginning. I have a relatively new home. It was built in 2017 and I had the option to install solar through the builder. They used Sunpower panel. I opted for the 4kW array which consisted of 12 panels. They were placed on the south side of the roof. I was happy with the production and did better than my neighbors because I always broken even or got a small credit when my true-up hit. Fast forward to fall of 2021, I had a single powewall installed for backup purposes and PG&E outages. While my first intention was to use the Powerwall as backup only. I saw the benefits of using it during peak times and recharging it during the day. If I drained to 20% It would take most of the day to recharge due having only a smaller solar. Best days in summer I would hit around 25-27kWH and peak around 2.8-3.5kW in depending on the year. Last fall I decided to future-proof the home by adding 6 more panels and an additional PW before NEM 3.0. Making my total combined system 6.03kW. The additional panels face the same direction as the original however, I'm barely seeing an increase in production. My generation is doing down week by week. Hitting 32kWh a day and peaking anywhere from 3.0-3.8kW. I reached out to SunPower and they said all panels are reporting correctly. I asked for access to see my individual panels since I have microinverters and I discovered that 7 out of the 12 panels that were originally installed when we built the home are producing 20% of the power compared to the rest of the system. I complained and they are investigating but when they found out I had a backup battery that a not an emphases system they don't want to help as much as the panels are not reporting an error. Is it possible the gateway is scaling back the power of these panels or do I need to put more pressure on SunPower. The reason I question it is because we had a grid-out event that lasted 4 hours and during which my solar system turned off when batteries were full, but when they dropped below 98%, the system turned on the solar and I saw 4.5-4.8kW of power. Which makes me believe the gateway has some control over output of panels. Weird coincidence?

 

[arnolddeleon]

In a grid out event the Powerwalls will shift the frequency to disable solar production if there is no place for it to go (e.g. not enough load and not enough room in the batteries, this is a simplified explanation). Some inverters can also limit their output based on the frequency shift instead of just turning off. None of the these is relevant when the grid is operational.

You seem to have correctly diagnosed most of your problem already, you have panels that are under producing. Your installer (SunPower?) needs to step up.