At Advanced LED Lights, we’re one of the most trusted online sources for LED grow lights, not only because of our extensive stock, but also because of our immense knowledge. A common debate among LED grow light users is whether they will save more energy running their lights at 240 volts or 120 volts.
Using 240 volts allows for larger headroom, which is ideal for growers with large gardens that use a substantial light setup. However, this does not ensure a saving on your electric bill.
Volts are analogous to the water “pressure” of a shower, the more volts that are available means that the conductor is capable of delivering more energy to the user. Twice the electrical power or energy can be delivered by doubling the voltage while maintaining an unchanged current, 20 amps for example. Doubling both voltage and also the amperage would deliver four times the power or energy. Doubling the power or energy does not mean that we cut our electrical bill in half. Let’s examine why not.
Electrical Energy Usage Measured In Watts
The watts consumed, and therefore the size of your electric bill, for running a water pump or other electric motors will be almost exactly the same regardless of whether you are running the pump wired at 120 Volts or 240 Volts.
Using our water pressure analogy, when distributing water through a pipe to move a water wheel, if doubling the pressure, or volts, at which the water energy is supplied to push the wheel, the number of gallons per minute, or amps, needed to do the same work is cut in half.
So if the pipe, water wheel, and all other factors the same, but deliver water at 240 psi, you would need half as much water quantity to turn the wheel at the same rate as if we were pushing on the wheel at 120 psi.
Electrical motor voltages are similar in this regard. If you have an electric motor that is designed to run at either 120V or 240V, which not all of them are, then the label on the motor will tell us that at 120V will draw about twice as much amperage as at 240V. Most electric motors will turn more efficiently at a higher voltage. The same concept applies to the amperage draw as well. At 240V, a smaller diameter circuit wire may be permitted – thus the circuit is a little less costly, however, not to a significant extent.