I'm renovating a house, and have been considering 24V or 48V DC outlets in a few rooms. Semiconductors become more expensive above ~32V, so 24V might be the sweetspot.
However, there's also PoE (24 or 48V!), so maybe that's the right approach. It's not like each outlet is going to run a heater anyway.
Lower voltage makes voltage drop across the line proportionally worse. Depending on the purpose PoE is probably the way to go since the wiring and hardware is all standardized and safety certified.
Unless you mean running AC and installing inverters in the wall? What is this even for? All my electronics are DC but critically they all require different voltages. The only thing I might benefit from would be higher voltage service because there are times that 15 A at 120 V doesn't cut it.
No, I meant running separate DC wires. I'm Europe, so it's 240 VAC vs 24/48 VDC. For small devices, 24 V would be useful in that you don't require an isolated SMPS, so cheaper endpoints are possible. Slightly less risk of burning down the house with some cheap Chinese AC/DC. 24 V is still high enough to use USB PD/PPS at 20 V, and I doubt I'll run enough current that the losses due to lower voltage would be a problem.
For PoE, I thought it was standardized at 48 V, but I see lots of cameras run at 24 V, and I think I've even seen 12 V. Seems a bit of a mess.
However, there's also PoE (24 or 48V!), so maybe that's the right approach. It's not like each outlet is going to run a heater anyway.