Nick,
220V ia definatley more efficient than 110V. Someone mentioned earlier about ohms law. That ohms law was for DC power. AC power has to include a power factor. P=IECosTheta. CosTheta is the power factor in ac. You want theta to be as close to zero as possible, because the Cos of 0 = 1, which means that the machine is purely resitive and no capacitance or inductance exists, so all the power is real.
Given the standard output in watts- Say 1000 Watts, and the voltage is 110V. Assuming the PF is 1, that would give you 9 Amps of current.
Given the standard output in watts- Say 1000 Watts, and the voltage is 220V. Assuming the PF is 1, that would give you 4.5 Amps of current. That doesn't sound like a lot, but the higher the wattage rating of the motor, the more difference 220V makes.
Say you have a 20 acre lake and you needed (3) 2 hp motors for aeration. You ran the aerators 24hrs/day, 7 days week at a cost of $.03 per amphr(I don't know the exact cost per hr, this is made up).
Those motors combined would draw 41 Amps at 110V
and 20.3 at 220V. That's a big difference.
$.03 for 1 amphr
At 110V
41A x 24 hrs/day x 7 days/wk x 52wks/year x $.03/ amphr= $10,745
At 220V
20.3A x 24 hrs/day x 7 days/wk x 52wks/year x $.03/ amphr= $5372
Another big question is efficiency.
Efficiency = Power Out/ Power In.
So if the motor is 85% efficient, and the input power is 1000W, then
1000x(.85)= Power Out
Power Out= 750 Watts
You are paying for 1000W and only getting 750 Watts.
So the closer the efficiency is to 100% or 1, the better off you are.
I hope this wasn't to cumbersome to read.
