Yes, however if the batteries are exhausted because there is more household load than the PV can cover then you are SOL. The batteries will need some charge and the PV needs to be supplying more than the loads demand. IOW you will likely need to reduce load.
Not sure Tesla's Powerwall has that capability.
I had heard that from also. No grid = no solar and if you take those batteries completely to zero it requires a manual restart that a homeowner can't do. To fair that's been a few years ago so be sure to get more input.
Just to clarify, the Powerwall has always had the ability to backup and AC couple with solar when the grid is down. The PW3 now has DC coupling capability so I presume it can blackstart.
Tesla allows you to set a low limit (usually 10%?) that it'll save as a reserve. Then every hour during daylight it'll try to power up the local micro-grid and see if the solar is greater than the load. If not it'll go back to sleep for another hour. Seems needlessly complex, but that's a side-effect of them doing AC coupling.
It definitely is a side effect but you have to give Tesla credit for leveraging AC coupling, so it could retrofit existing solar installations, which was their initial market. The first time I heard the term AC coupling was at the rollout of the first Powerwall in 2015 at the Tesla Design Center. My Outback Radian at that time could not do AC coupling and in 2018 when I bought an Outback Skybox. it took Outback nine months to enable AC coupling in the Skybox.
DC-coupled systems, that's how they work. AC-coupled systems need the inverter to power up and make AC for the panels to sync to and produce power. #Catch22
Definitely test all realistic situations so you know what to expect!
Indeed! I'm just testing some code to automatically turn AC splits on and off depending on SOC, so I don't have to manually control loads, but with a good understanding of your system and a guess at the future weather (the sun will come up tomorrow, or there's a hurricane headed your way) will allow you to tune your habits to minimize generator runs (or grid purchases).
No need to clarify on my part but I have been on Tesla residential sites when I worked in Puerto Rico after Hurricane Maria that crashed and would not blackstart. It was a very hectic time so I didn't get all the details since I was one of just handful of electricians. We had no choice but to abandon them and move onto the next site to try to help them.
Not sure who this is directed at, the OP didn't mention Tesla. I have EG4 18Kpv and PowerPro batteries, and I'd do it again. I had three grid-tied inverters and the switch to battery power _could_ have preserved some of them in AC-coupled mode, but once I looked at all the additional complexities I threw them out and went with EG4.
