DC Watts vs AC Watts

[dzl_]

Originally Posted by somewhereinusa

One thing not mentioned here. It is quite easy to safely wire AC from one end of your bus to the other to run any 120V appliance. Twrlve gauge will run pretty much anything rated for 120V at that distance.
With DC you have to run increasingly larger wire as power requirements and distance increase. And the size requirements go up quite rapidly.
My fridge, microwave and induction cook tops are about 20 feet from the power source. Wouldn't have been feasible on DC.

You are probably already aware, but just to clarify for anyone else reading, what you are describing is true in practice, but not for the reasons stated (AC vs DC).

A lower voltage system will require a higher amount of amps to deliver the same amount of power.

As an example, a 1000w load, will pull roughly:
83.3A @ 12v DC (common DC voltage)
41.7A @ 24v DC (common DC voltage)
20.8A @ 48v DC (common DC voltage)
8.33A @ 120v AC (US AC voltage)
4.54A @ 220v AC (EU AC voltage)
1.00A @ 1000V DC (common max string voltage for solar)

Your wire size is proportional to the amperage it will carry, and the round trip length of the wire run. For a given load, higher voltage = lower amperage = smaller gauge wire. I don't believe it makes any difference whether its an AC or DC circuit.