Yeah I think you'd definitely want a battery. TBH I just threw that question about grow lamps in there to draw attention to how you can not only run low/medium power solar setups in Germany, but you can also grow a couple of weed plants for your own use.
I think Germany might actually be the only country in Europe where you can do that fully legally? I used to think growing your own weed was fully legal in Spain and Portugal, but now after speaking to some of my family who live in Spain, I think it's really just a grey area and not technically legal at all.
Anyway, I'm not actually trying to grow my own weed or anything like that, I just think it's a stupid thing to make illegal. So go Germany, we're all counting on you!