I have no idea, just want to note that those usual "balcony power plant" kits would be rather infuriating: If they don't see any power from the net they think they're unplugged and thus don't provide any power, that is, they can't be used to bridge outages. That's very important safety-wise, not only would they expose 230V at their power plug if they didn't act like that, it's also very problematic when consumers feed electricity back into the net when the net is down because people might be working on it. There might be some models with separate outlets you can use when the power is down but it's definitely not going to feed your home grid. It's also not going to work at night so you probably want a battery backup system with such a function.

It's also possible to have a switch-over system where your home grid gets isolated from the main grid when the main grid is out and you only feed your own home, and such systems are available off the shelf, OTOH now you definitely want an electrician to do the installation. And even with Slav YOLO attitude it's still going to be more pricey.

On the upside, though, all those small inverters following network frequency electronically have a stabilising effect on the network that shouldn't be underestimated, making it much more capable of staying up while large loads get connected or disconnected.