I picked 600w for nice round amperage numbers in the above math; even just a few hundred watts presents the same issues though. You could fit a decent size set on the balcony, covering the outside of the balcony railing.

I wouldn't be so sure on the second point. I live in a 3bed apartment with 2 main outlet circuits. 1 supplying the livingroom and half of one bedroom. Another supplying the other two bedrooms + the other half of the 3rd bedroom.

Between the main entertainment/lighting electronics in the livingroom, the portable ac in the adjoining bedroom, the watercooler/heater, and recently a set of ebike battery chargers; that circuits base load sits around 6.5a during a charge cycle, with peaks right around 15a when the ac runs+the water cooler, occasionally peaking right up to 16.5a. I've tripped the breaker a few times running the vacuum at the wrong time ontop of those.

The other bedrooom circuit is similarly loaded with a couple computers, device chargers, and another ac (cooling is crap in this place plus our unit faces the sun all day); though not quite as heavily as the other circuit.

The living room circuit is where a solar system would be installed (it's where the outdoor outlet is connected) and the main appeal of a system like that is not having to modify wiring since we're not allowed to touch that as tennants (the corporate landlord is rather unlikely to allow modifications even from a licensed electrician either).

Supposedly the solar inverter would shut off during a mains power outage, but is it fast enough to prevent shock if the plug was disconnect and touched?

IDK, interesting systems, just curious about them. I'll have to look closer when they're actually available.