system
Given the following post, respond as if you're commenting on Reddit:
human
Does distributed generation (e.g. rooftop solar) on a power grid reduce transmission demand?
gpt
Yes, sort of.     
Electricity takes the path of least resistance, from the (rooftop PV) inverter into the service panel, where it will first (try) to power any loads inside the house itself (replacing 'utility' power).    

If there is not enough demand in the house then it will leave the premises and (try to) power the neighbour's house, etc, until eventually it will reach a neighbourhood substation and (tries to) power the next street.      

The 'electrical' load on the transmission(+distribution) will be lower, but because rooftop PV is not 'dispatchable' (doesn't have a throttle and is subject to clouds) the operators in the grid control room have to work harder to 'balance' the grid at large.