[samcheng]

50 or 60 Hz AC, especially 3-phase, makes it really easy to build and operate electric motors, too, and to transform between different voltages.

The OP’s argument is that solar power generation, plus the fact that most electrical consumption is now fundamentally DC-friendly (LEDs, electronics, electric cars, etc.), may change the equation. The concept of a whole-house rectifier is an interesting one, and something that is already used in some data centers. You still have the problem of different electronics wanting different voltages, though...

[eigenvector]

As you note, for facilities like data centres that are engineered for a specific type of load, a building-level rectifier makes sense. For a home where you have many devices using a little bit of power at a variety of voltages, you're going to end up with lots and lots of small DC converters everywhere which defeats the point. Just run 120 VAC.

[dreamcompiler]

> 50 or 60 Hz AC, especially 3-phase, makes it really easy to build and operate electric motors, too

Three-phase motors are never used in residential settings, and most residential motors would be more efficient as brushless DC. There's no need for sinusoidal AC motors any more except in specialized industrial applications.

[samcheng]

I agree - brushless DC motors really make AC motors obsolete in 90% of use cases.

[7952]

Whilst most devices may use DC internally that may not be true of consumption. You still have electric showers, cookers, hobs, washing machines, dryers, heaters, air-conditioning, vacuum cleaners and kitchen appliances like blenders.

[dreamcompiler]

Yes. High-power residential loads like heaters would still work best on AC because HVAC is safer than HVDC.