I like this idea.. I've actually been thinking about something like this for a while.
You could have a DC distribution panel next to the main one, that converts the mains voltage to 24/48 VDC for lighting circuits and DC receptacles. 240 Watts (10 or 5 Amps) could be enough to power a lot of devices on a branch, while still allowing the wires to be reasonable (14 AWG or smaller).
I think the bigger win would be for LED lighting circuits, but device chargers could use it too.
Why? I can't see any gain to converting to 48 volts if you just have to convert it again anyway. There isn't much difference between converting from 120 vs 48.
You could have a DC distribution panel next to the main one, that converts the mains voltage to 24/48 VDC for lighting circuits and DC receptacles. 240 Watts (10 or 5 Amps) could be enough to power a lot of devices on a branch, while still allowing the wires to be reasonable (14 AWG or smaller).
I think the bigger win would be for LED lighting circuits, but device chargers could use it too.