I live connected to the GRID, though I have been making my live hood with Electrical and Electronic Engineering.
By definition, higher the voltage less the losses and easier to work and control the power.
I have installed wind mills and Solar Panels, non have been below 48 volts, several 120 or 240 volts battery systems.
Off course I have done some 12 & 24 volts for very small special systems.
Cost may be a factor, as well, battery maintenance for high voltage systems that some people may consider for the initial system, but for long term, there are benefits non available in the low voltage systems.
Nando