Tesla Versus Edison – The Battle Between Ac and Dc

The fight for consumer adoption of the two different forms of electricity is a little known chapter of history that had a big impact on how we live our lives today.

As everybody knows, there are two types of electricity. One type we get from batteries and is called DC, short for direct current, and the other is what powers our lights and plug sockets, AC, alternating current. It could, however all of been very different.

The story of how we ended up where we are today is of conflict between powerful industrial organisations and bitter personal rivalries. The backdrop for this drama was the dawn of the electrical age, in the late 1880’s.

Thomas Edison is one of history’s best known inventors. He was not only a pioneer of many technologies around power generating and distributing, he was also very much a businessman. Edison favoured direct current, one of the reasons being that it was simple to use with incandescent lamps, which were the main users of electricity in the early days.

There were practical advantages to using direct current. It was possible to use storage batteries to ensure continuity of supply for instance.  It also simplified the scalability of power generation. The other reason Edison favoured the direct current standard was that he owned many relevant patents that he was anxious to profit from, including a meter that only worked with DC.

Nikola Tesla had worked under Edison. Telsa was a remarkable innovator, but some of his ideas were too radical for Edison to accept. When Tesla’s proposals for an electrical system based on alternating current were dismissed out of hand by his employer, Edison vowed to set out on his own.

Although initially there were many practical advantages to using direct current, technology rapidly caught up. In addition to this, as research progressed the advantage of an alternating current network became more apparent. It is much easier to transform the voltage of alternating current. This means that power can be transmitted over long distances at high voltage, but with low current and then simply rendered into the high current low voltage form that consumers needed. This is less wasteful than transmitting power at lower voltages.

Perhaps the most interesting aspect of this story is the bizarre propaganda campaign that Edison waged to promote his favoured system in the face of the great many practical arguments against it. Edison arranged for a number of animals to be killed using AC, in order to put forward the idea in the public mind that it was inherently unsafe. This culminated in a circus elephant named Topsy being electrocuted after it had caused the death of three men.

Edison was an ardent opponent of capital punishment, however he was so desperate to smear the reputation of AC that he was willing to bury his principles and secretly pay a man to develop the first electric chair. This was used on convicted murderer William Kemmler, but did not kill him, instead only inflicting horrific injuries.

Ultimately there could only be one victor in the battle between AC and DC. The episode stands however of an example of why we shouldn’t always listen to the voices of those who oppose change simply because they stand to lose money.