Ask HN: A DC Powered Home?

I’ve been thinking about the fact that contemporary home electrical wiring is heavily predicated on AC for power delivery which makes sense for power transmission as it’s been done for most of the last century or so, but with the shift to solar and battery storage, I’m wondering whether it makes sense for in-home electric wiring to move from 120V AC to 12V DC or something similar. Since I’m largely ignorant of practical electrical engineering skills, I’m wondering whether this is something that makes sense and what the engineering challenges would be. Certainly, other than my kitchen, it seems like everything in my house is converting its electricity to DC anyway (or could be easily modified to function with a DC power supply, like the lighting). And perhaps there’s no compelling reason why we need AC for the fridge, microwave, stove, toaster oven or other kitchen stuff.

Unless we standardize on 380-400v

High voltage DC over 50 V is usually considered pretty dangerous.

I've actually went far in planning and acquiring gear for my apartment, though it's a low priority task for me.

Turns out there are tons of stuff that sip power (set-up boxes, Ethernet switches, NAS...) that can either be powered directly by Power-over-Ethernet or through a splitter (DC-DC converter). That can be handled by a PoE Ethernet switch, which itself is usually powered at 54VDC, so it's also an excuse to run a homelab on 48VDC and get rid of tons of power supplies.

However, DC isn't well suited for the entire home for several reasons, mostly due to cheapness and historical reasons. For example, AC breakers are dirt cheap because arcs naturally extinguish when current crosses zero volts, whereas DC doesn't.

There are areas where DC is used. I work on telecommunication gear where nearly everything is -48VDC, but the beefy copper busbars needed to push large amounts of power through them would make a homeowner cry at the expense. Higher voltage is possible to compensate, but you enter not-safe-for-touch territory and I'm not knowledgeable about that.

The compelling reason is short circuits, and power ICs are cheap and good these days. With some EE knowledge, the issue is energy getting lost in house sized runs with DC.

For things like your IT closet, it does make sense to have one AC DC converter that does PoE to all of the devices, but for your kitchen it doesn't.