Similarly the UK requires a "g98" notification for all solar installation, including balcony. But it's just a web form and free.
I have been wondering if there is a smart way to make use of "island" solar at home, but not thought of one other than heating assist (pipe tape heater).
I picked up one of these because of how cheap it is; can charge anything with a USB port, laptops, phones, torches, etc.
- https://www.action.com/de-de/p/3222881/re-load-solarmodul/
- https://www.action.com/de-de/p/3222880/re-load-faltbares-sol...
Despite the low capacity, given what can be done with a phone and a laptop, this is still potentially useful.