This would be excellent for solar because it removes the efficiency loss from the inverters. AFAIK it's very hard to add/remove loads without spiking power to everything else on the line. A friend of mine applied for a job at a company that was trying to run DC in the home but it's not a trivial endeavor.
Almost everything complex does run on DC internally, but you feed those via AC adapters that then invert it to DC. You'd have to get bespoke DC-DC adapters (transformers, really) for everything.
AC-DC are effectively -> AC + power correction boost to even higher AC, then high voltage DC, the AC (high freq), then transformer, then low volt DC + feedback to the primary DC ; {then DC->DC (potentially)}
DC (high) voltage to DC would skip the 1st few steps of AC->DC.
> Almost everything complex does run on DC internally
almost everything runs on either 5V or 12VDC. What you would need are appliances that bypass the wall-warts/adapters and tap directly off DC, but this comes with some significant challenges. I'm already talking way outside my wheelhouse though, so I'll stop before I make a mockery of this topic.
I meant it more in the sense of: "[in the current appliances environment] is there even a use to running DC in a/your home?"
Its very cool as a theoretical exercise and you could probably make a proof-of-concept house, but if you want to live in it and use literally anything non-bespoke, you have to convert DC to AC, which kind of defeats the purpose.
absolutely, in the here-and-now. But as a system, if the entire appliance/solar industry committed to a household DC standard (and if it was technically feasible, which it very well may not be), then you might have something. Solar would just provide regulated DC (which presumably would be less lossy than inverting to AC). But the devil is in the details: a DC system would have to have a comms channel announcing "hey, I'm an appliance X, and I intend to draw X amps from the DC bus" and coordinate it with the supply, otherwise it will cause all other appliances to experience a drop in voltage. That's just one of the problems, there are others.
However, if that were worked out, you could have DC plugs in the house for all existing appliances and fixtures, and theoretically you would get a gain on both sides (no inverter, and no v-regulator (or a simpler, less lossy one)).
I think one of the "easiest" steps would probably be to run a concurrent circuit of DC from a central inverter, stepped at the same voltage as the solar / home battery output.
Then you wire your EV charger and big electrical appliances like stoves, ovens, microwaves, fridges (?), electric boilers, central AC, heat pumps, etc. into that DC circuit.
That alone would switch the majority of your electrical consumption to DC. Maybe long-term, you could have a special DC socket that you plug toasters, kettles, crock pots, vacuums etc in to, if they became available and cheaper.
