Which will save more cost of electricity: 125 or 225?

Question

If I ran one device rated at 125 volts 100 watts from a 125 volt power supply, and another device rated at 225 volts 100 watts (same wattage) from a 225 voltage power supply and the both voltage power supplies has the same diameter wires (type of conductors), which device would waist more electricity, making the electric bill more expensive?

Answer 1

Lets examine the power equation P=IV where power (watts) equal I (current) times V (voltage). Since power is the same and the voltage is different, the current is directly proportional the the voltage difference.

If your asking a physics homework question, V=IR where the voltage drop due to heat dissipation is equal to the current times resistance. The resistance in both cases are the same and since the 125V pulls a higher current (0.8A compared to 0.44A of the 225V), its going to suffer and higher voltage drop. So in this case, the 125V is going to waste more electricity

Answer 2

Neither. Both use EXACTLY the same amount of electricity since they are both 100 watt devices. Since watts = volts x amps, the 225 volt device will use fewer amps, but the electric companies do not care how many amps you use, they only care how many watt hours you use. That is because amps alone do not measure energy. Now watts are not a measure of energy either, they are a measure of power. Power is the rate of using energy. If you use 100 watts for one hour, you have used 100 watt hours of energy. The real unit of energy is Joules. One watt is one Joule per second. For some reason the electric companies don't like to bill you for Joules, they always bill in kilowatt hours. Go figure!

Answer 3

Power draw = (current) (voltage)

A given electrical appliance will require more current at a lower voltage. The more current, the hotter the wire gets for a given wire thickness.

Current is the rate at which electrons move through the wire. Voltage is the pressure that's pushing the electrons. The higher the pressure is, the fewer electrons you need to put a specified amount of energy into an application, because each electron will have more energy to impart.

So the higher voltage causes less energy to be lost as waste heat during the transmission of electrical power, assuming that the same wiring and the same applications are being used in either case.

Answer 4

Wasting electricity and using electricity are 2 different things. While under the above circumstances, a 225V device will USE more electricity but it will probably use the electricity more efficiently, thus causing less waste. The amount of usage and waste depends completely on the device that is being used and the amount of work that is being done as a result of using the electricity.

A small 5000 BTU window air conditioner that runs on 120V will probably waste more electricity than an 18,000 BTU window air conditioner that runs on 220V simply because you will not have to run the bigger unit as long or as often to get the same or better results.

Answer 5

Since the wattage is same in both the situations, the bill you get will be the same, for a given period of usage. I also think that the difference in the dissipation of energy as heat would be negligible. Otherwise we would all be using 225 volts, don't you think? ;-)

Answer 6

I am not sure but I believe it is based more on the draw on the electricity from devices. They use 240 in Europe all the time.

Answer 7

125 would cost more...

225 would have 2 hot wires not one and be less resistant to the current..

Answer 8

Hallo Mr James, H
We know that v=Ir
so according to qen.
device with grater resistance (225volt100watt)
would waist more electricity.

Answer 9

well first of all more offten then not its 110 and 220, and the 220 will save you more money, for some reason. don't know why, it just does

Answer 10

the first one.