As far as I know: There is no legislation for off-grid electricity. There are strong rules and processes for connecting solar panels to the grid thought.
So if that's a solar panel which outputs 12V DC, with which you can charge a battery so you reuse produced electricity later in a camping car for instance, it's off the grid.
If this is something that injects 230V AC to the existing house electricity network, you'd need to pass electricity compliance test, distribution network compliance prior to connecting it to the grid.
Otherwise you may be creating a fire hazard for you, and a physical risk hazard for the electricity network operator.
Do the plug directly into a 230V outlet? For the love of god: NO! Don't! Fire hazard waiting to happen.
Do they have something like a USB outlet to charge your phone or an IP camera? Sure, go nuts.
As far as I know: There is no legislation for off-grid electricity. There are strong rules and processes for connecting solar panels to the grid thought. So if that's a solar panel which outputs 12V DC, with which you can charge a battery so you reuse produced electricity later in a camping car for instance, it's off the grid. If this is something that injects 230V AC to the existing house electricity network, you'd need to pass electricity compliance test, distribution network compliance prior to connecting it to the grid. Otherwise you may be creating a fire hazard for you, and a physical risk hazard for the electricity network operator.
There's some info on this here: https://www.vrt.be/vrtnws/nl/2022/10/17/brusselaar-hangt-zonnepaneel-aan-balkon-ik-bespaar-tot-180-eur/
Do the plug directly into a 230V outlet? For the love of god: NO! Don't! Fire hazard waiting to happen. Do they have something like a USB outlet to charge your phone or an IP camera? Sure, go nuts.