AC vs DC: Current Battle

If you’re a history buff you may know that Thomas Edison and Nikola Tesla were embroiled in a late 1880’s battle known as the “War of the Currents.” Edison had developed direct current (DC) which was the standard in the early days of electricity.

However, DC had a problem in that it was not easily converted to higher or lower voltages.

Tesla came up with a solution to this issue known as alternating current (AC). AC was able to carry power more easily over cable lines using transformers. The DC system would require much thicker and more expensive (not to mention dangerous) wires to carry the same amount of power as the AC system.

But what are AC and DC exactly?

DC (direct current) is a current that flows in one direction. A battery is a classic example of a source of DC power. The energy flows from one end “positive” to the other end “negative” and is constant.

AC (alternating current) on the other hand, flows in one direction until is reaches a peak voltage, at which point it changes direction until it reaches 0, and then the polarity changes ones more.

The electric system that powers your home probably uses AC power. A lightbulb, for example, that is 60 Hertz will go through 60 “cycles” of current change. Your lightbulb is actually constantly flickering at 60 cycles per second – however this is too quick for the human eye to observe, and the light appears constant.

DC doesn’t have this flickering effect since the flow of energy is constant.

Is AC actually better though?

While our electricity is still predominantly powered by alternating current, many newer devices use DC power. Computers, LEDs, solar cells and electric vehicles all run on direct current. Newer methods for converting DC have also become available, and some companies are finding ways of using high voltage direct current (HVDC) to transport electricity long distances with less electricity loss.

To find out which currently flows the fastest and produces the most power, we’re employing the most scientific method of them all: a VS competition! Pick your side and let the battle for power begin! This competition starts at 11 AM ET on 9/7 and goes for 48 hours!

Bonuses are detailed in your notifications. Have fun! For science!

Art by Elena Daly