And indeed, they can tax excess solar, but they can't tax the power you use yourself. Backfeed tax gets too high to use the grid as a battery? Buy a home battery, problem solved.
^Not recommended literally due to brownouts/etc, but a cheap power management IC on a breadboard can solve that. Alternatively, add a battery/etc.
Home solar panels and batteries are just like this except on a bigger scale; and with (hopefully) more QC.
This is incorrect. Treating solar panels like batteries for specific appliances (or integrated like the panel on a Solocam S220), is not the use case nor is this a discussion about off-grid or microhomes.
I would suggest not making broad statements about what can and can't be taxed in the future.