I was not planning on using it, I just state that your name is just a detail within data-mining. Does not matter if this is Windows 10 or another release, so not using it is actually not really an option.

And you think just using some fake username will prevent Microsoft from knowing who you are? Sounds a bit naive, unless you plan to do utterly nothing on that computer. They won't even need a key-logger for that.

You would be amazed by the cables you would need for that. It is not so much about AC or DC but about voltage levels. With standard copper cables from the mains, you would be able to transfer the energy from 1 old fashion light-bulb before they would overheat. Not to mention the amount of energy which would be wasted within you cables. There is a reason why electric companies use high voltage lines, generally higher voltages mean higher efficiency but also higher risks, AC or DC.