yes see that's makes no sense to me all the more reason I might as well learn thus shit now lol! plus it's a good trade to have!
A quick lesson in electricity:
Watts=amps x volts or put differently, amps=watts / volts
Wire thickness (gauge of wire) is determined by amps:
10 gauge wire is good for ~30 amps
12 gauge for ~20 amps
14 gauge for ~15 amps
There is more to wire size like length of the wire (longer runs need larger wire), multi-strand vs solid wire, etc., but for today's lesson this should cover it.
Now using the above information, imagine running 2200 watts of lights. On 110 volts that would be 20 amps (2200 watts / 110 volts = 20 amps). You would need at least 12 gauge wire for this.
Now use the same 2200 watts on 220 volts. 2200 watts / 220 volts = 10 amps. See there, you only need 14 gauge (or less actually - say 16 gauge).
Look at any electrical appliance (blender, vacuum, saw, etc) and it should have a tag or stamping that states how many amps it draws. Take your a/c for example and say it draws 9 amps. Assuming it operates on 110 volts, that would make it 990 watts.