Solar not producing during grid outage.

Solar not producing during grid outage.

I have both solar panels and a powerwall installed and operating just fine. Recently however we lost grid power on a clear and sunny day and saw that solar production also went to 0 at the same time, as soon as the grid came back up solar production also returned. Our powerwall covered us fine during the outage but no power came from the solar panels to either charge the battery or power the home. It was my understanding that when you have both solar panels and the back up powerwall, the inverter allows energy generated by solar to go to either the home energy use or to recharging the battery.

Has anyone else had this issue and if so how do you resolve it?

mcdonalk | March 6, 2019

I have not had this issue. Of the several significant power interruptions we have had in the past year, only one occurred during the day, and I seem to recall that I noticed nothing unexpected. Is it possible that during the interruption that you lost internet connectivity, in which case the application would not be reporting current information?

jto2v | March 8, 2019

I thought the internet might be the case too but it stayed on during the entire outage and I could see the supply from the powerwall in real time in the app. I actually called Tesla support about it as it was happening but in between calling and speaking to someone the grid power had come back on, solar was back producing, and on their end nothing looked amiss. I'm wondering if its a setting or an issue with the inverter, like perhaps it was configured as if there was no back up battery and to operate in a safe mode when grid power went off? I was planning to call customer support again but wanted to check first on the forum.

WSE51 | March 29, 2019

jto2v did you get info from Tesla about this? has a more active forum about Powerwalls, and this thread has some pretty technical discussions, including someone else who seemed to have the same issue:

My system is only 3 days old. We simulated a power outage and the solar kicked in after 5 minutes (installer said that's the plan); and the Powerwall provided power during that 5 minute delay.

jto2v | April 18, 2019

@WSE51 Thanks for sharing, the thread you shared was helpful. The power outage we experienced was relatively short which explains some things. I'll try a simulated outage and see what happens.

Tesla-David | April 18, 2019

@jto2v your experience does not represent what I have experienced over past 10 months with our 2-PW2 installation coupled with our 13.2 kWh solar PV system. We did three backup tests and the solar continued to charge the batteries during the outages. Your solar should definitely be charging up the PW2's and supplying your home unless the PW2's were already fully charged during an outage. Hope you get to the bottom of this. Please report back your findings.

fourspeedolds | April 22, 2019

I had this issue with my powerwalls(3) when power company shut down grid. I lost all power to the house & guest house (that's another issue). After 5 min my powerwalls brought the house back up & supplied power. I went outside & found the solar was not producing, inverters said "external events". My app showed powerwalls @ 99% & it was in backup mode & solar not producing. I called Tesla about it & it turns out the solar wont produce if it has nowhere to put the power. Since my batteries were @ 99% they didn't need to be charged & the grid was down so no place for the power to go, solar was kept off.

DermMD | May 2, 2019

Thanks. This I did not think of but makes sense. Also good to know that Tesla's setup can isolate the PV. I think in truth solar panels will be active for as long as they're exposed to the sun and unlikely that they can be turned off. Or can they?

gpez | May 3, 2019

@fourspeedolds is correct, this is the reason why. The Gateway will protect a fully charged Powerwall from overcharging by shutting off the solar inverters. They'll turn back on when the Powerwall charge drops low enough to safely be charged. I've actually noticed that with my microinverter system some will actually stay on and "float" at exactly the house consumption level instead of discharging or recharging the Powerwall.

The app REALLY needs to tell you this information. Something like "The Gateway has turned off solar production to protect the Powerwall from overcharging during the utility outage and will resume production when the Powerwall has sufficient capacity." Would be super helpful.

@DermMD they can be turned off. Think of it like a switch that your inverters have that can disconnect the panels. If your inverters are UL1741 SA compliant ( they will turn off if they detect the grid frequency is too high or too low from normal which is 60hz in the US. The Gateway will increase the frequency to trigger your inverters to turn off and return back to normal when the solar input is needed again. Unfortunately some (including myself) are finding that the way the frequency changes affects sensitive electronics such as computer UPS, home automation systems, and LED lights.

As others have mentioned TMC has a lot of threads about this issue.