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Comment by samtho | Hacker News Reader

This is correct. I see a future where there is an optional 48VDC line that is run in our homes to power stuff like LED lights and dedicated USB ports. This can become especially important for homes that use solar and stored electricity where you might be having to go from 48VDC -> 120/240VAC -> 12VDC -> 5VDC (see note) with each conversion resulting in the loss of some power due to the fact that these cannot be 100% efficient.

Note: a lot of flyback-style transformers are setup to step down the AC voltage 1/10th (12V in 120VAC, 24V in 240VAC) because transformers are cheap/abundant for that. It’s cheaper often to put a buck converter that takes any voltage from 12-24V and convert it to a fixed required voltage.

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If we’re moving to a new standard I’d much rather we standardize around 240V DC with an improved plug design.

You’d have HUGE savings on the copper required for a standard home, plus you’d get a substantial increase in power capacity.

240VDC conversion to any low voltage (1V for cpu/gpu) won't happen.

Most of the copper is spent on carrying hundreds of amps at low voltage not the 12V lanes.

240VDC is way too dangerous for residential use. And really it's not super practical to drop that down to 5v for charging your widgets. 48V makes much more sense.

And for that matter, I wouldn't want 240VDC on utility poles either. If a line goes down, it's so much more dangerous.

The more sane solution would be a high capacity DC converter installed next to the line transformer that feeds your street. DC infrastructure inside the home makes total sense at moderate voltages. City scale DC at line voltages is honestly terrifying.

All of Europe uses 220v-240v for residential use.

That’s AC, not DC.

Irrelevant. It’s virtually the same risk, the only minor difference between 240V AC and DC is a hypothetical arc is harder to extinguish in DC (AC benefits from the oscillation slightly), but if were to the point that wires are arcing we’ve already got major problems.

Huh? DC is generally considered safer than AC at a given current or voltage:

https://en.m.wikipedia.org/wiki/Electrical_injury

It is, however, considerably more complex to make DC circuit breakers or ground fault detection devices.

Nonsense. I have 600v DC from my solar panels. It’s not magic, just needs proper insulation.

Utility poles are 10’s of thousands of volts (AC), I guarantee you that will cook your goose AC or DC.

Why not just throw in a DC/DC converter from 48 to 12V? You need protection anyway (so that failure won't take down your whole 48V microgrid) and perhaps even management.

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