The local electricity authority here (and it is far from unique in rural France) has maintained its network for decades without outside aid (other than standardisation, very good thing). It is part of the national network 1) by legal obligation 2) out of need to distribute half the electricity consumed from outside sources. The second constraint could change with increased local generation.

I'm not suggesting an independent local grid would be a good idea, nor that there is some magic bottom-up solution for electricity generation. Just that I think your sweeping disqualification of local potential is mistaken.