Plug-in Battery

With all the latest knee jerk reactions, people are thinking the low installation costs options.  I have double checked my understanding, looking up available products.

First of all, the regulations called for their own disconnect, ie it should not be plugged in.

Then I did all the maths.  For the balcony solar, which I won't need, one would have to be very lucky to get a payback within 5 years, even with South facing balcony.  The only saving grace is that micro inverter and solar panel should be good for 25 years.

Not taking into the fact if electricity price is decoupled from gas, electricity price could be a lot lower, hence increasing the payback.

I am more interested in battery, but a small, AC coupled battery has a bad round trip loss, taking depth of discharge into account, it is hardly any buffer.  And in the best case scenario, I could get payback in 3 years, by then, the battery is half dead. I just generated another piece of rubbish...

Also not taking into account of the price is decoupled, that would easily make the payback longer than it's life.

Let's stick with my original plan, in 7-10 years time, when the string inverter packs in, get a hybrid inverter with a battery then.  Hopefully by then the sodium battery technology is matured and cheap.