It's not the low voltage system you are hoping to see but right now there's a push in Germany to have lots of small photovoltaics systems installed. These setup

It's not the low voltage system you are hoping to see but right now there's a push in Germany to have lots of small photovoltaics systems installed. These setups are called "Balkonkraftwerk" ("balcony power plant") and allow up to 600W (or is it 800W now?) to be feed into mains (via a special plug and receptacle, for safety reason as I assume) without any approval required (you are only required to inform your electricity provider of the fact that you installed one). People renting still need to deal with their landlord of course. Drawback: any excess power that one does not use oneself is fed into the grid without compensation. It's a step in the right direction, I guess?