

It’s a safety requirement. If the power company powers down a part of the grid for workers to safely perform work they don’t want your solar to kick in and kill the worker.
If you want your battery or solar to power parts of the house when the grid is down you need islanding. That disconnects part of the house grid from the street grid keeping any workers safe.
I’ve got a 11.64Kw setup it went live in July 2023 and I just hit 40Mwh generation. It does about 90% of my power needs. That’s including charging two EVs and a big AC.
I would have liked to go bigger but where I live going above 11.7Kw requires a bunch of extra paperwork and insurance.
Overall no regrets. I’ve generated about $6K in savings and it cost me $13K so I’m about halfway to break even. Power rates have gone up recently so my savings should also increase.
As far as battery recommendations there are a lot of factors.
If you have net metering and a good stable grid. It’s not worth getting a battery.
If you aren’t able to export and are going to generate much more during the day then you use battery makes sense.
If you can export but lack net meeting you have to look at the expected price difference between buying power at night and selling during the day. It may be more cost efficient to add more solar instead of a battery and use the extra generation to offset buying at night.
For battery if you want backup when the grid is down you need islanding. Otherwise everything shuts down for safety when the grid does.
The other thing to consider is a single line inverter vs micro inverters on each panel. If your panels are going to get the same amount of sun a single inverter is usually better.
If you have something like a tree that is going to start throwing shade on one panel much sooner than the others then micro inverters are better.
With a line inverter if one panel in the line has 50% shade and the others are in full sun the whole line is going to be at 50% generation. With micro inverters just the one is going to have low generation.
Micro inverters are less efficient however and as you have one on each panel you have many more points of failure.
Let me know if you have any other questions. I did my installation myself so I did a lot of research.
Here is a recent generation vs usage day for me.