At the EU level these exist. In Germany they're called balcony power plants: https://de.wikipedia.org/wiki/Balkonkraftwerk https://de.wikipedia.org/wiki/Balkonk

At the EU level these exist. In Germany they're called balcony power plants: https://de.wikipedia.org/wiki/Balkonkraftwerk https://de.wikipedia.org/wiki/Balkonkraftwerk They're capped at 800 W in Germany for fire safety reasons and because residential fuses are rated at 16 A. You can buy complete sets at hardware stores and even supermarkets like ALDI. They plug into a wall socket like any household appliance. You can use a WiFi connected smart socket to measure the output if the inverter doesn't come with an API. I've seen an 800 W "ready to use" one at a German discount supermarket for €300, although prices can reach €1500 and more for some of the fancier models. You do have to register them online but you don't have to inform your electrical company. If you're a tenant, your landlord has to approve of you installing one unless they have a legitimate reason to refuse you (generic "safety concerns" or complaints about them being ugly are not valid).