[alexhutcheson]

Interesting idea, but running an extra set of cables is a non-starter. The cost/benefit analysis would never make sense for existing structures, and newly built structures wouldn't do it unless it was almost certain to become a universal standard. This is a classic chicken-and-egg problem.

You would also still need something similar to a wall-wart to step down the voltage to whatever your device actually uses (e.g. from 12 V to 5 V to charge your phone), so its not clear how much benefit there would really be from such a system.

Whatever specs we adopted would probably also end up not being appropriate for some future devices, so we'd probably go back to a substantial number of devices bundling their own PSUs anyway.

Interesting idea, unlikely to ever be worth the cost. If wall-warts really bother you, then just invest in some wall outlets with integrated USB sockets - there are many good options on the market.

[gwbas1c]

Also, the biggest non-starter is just how inefficient it is to move 12v any reasonable length. 12v domestic wiring only makes sense in very tiny small dwellings. (Think studio apartment or 3rd world country shack.)

Otherwise the voltage sag and resistance makes it cheaper and more efficient to do normal 120/240 voltage with device-specific converters. (For example, if I had to run 0-gauge cable from my breaker box throughout my house to support 12v, the cost of copper alone would be prohibitive.)

I honestly think standardizing on USB for devices that can use it is the best approach, given that we already have tiny AC->USB converters that don't block other plugs, and outlets with USB built-in are on the market. Furthermore, I wonder just how much we can shrink the typical wall-wart so it won't cover other plugs?

(I also think we're better off trying to do a global domestic 200 or 400 volt DC standard.)