Rare win for Germany, the the land of bureaucracy, made it easy to install *small* residential solar.
You can buy small solar panels in the supermarket, and plug them into the wall socket, which normally is a no no. Per household a maximum of 800 watt though.[1] For more you need something proper that does not just connect via a normal wall socket.
[1] Maybe also 2000 watt but only 800 feed into the grid?
You can have up to 2000W panels with an inverter up to 800W. Note that the 800W is what you're allowed to produce, not feed in, but it can still be beneficial to overprovision panels because with 800W of panels you won't produce 800W of power in mornings, evenings and winter. Panels are also cheap af in Germany currently, about 60€ for a 440w panel.
You can buy small solar panels in the supermarket, and plug them into the wall socket, which normally is a no no. Per household a maximum of 800 watt though.[1] For more you need something proper that does not just connect via a normal wall socket.
[1] Maybe also 2000 watt but only 800 feed into the grid?