I will be exploring the contentious battle between Thomas Edison's direct current (DC) and Nikola Tesla's alternating current (AC) to become the dominant form of electricity distribution. This period in the late 1880s became known as the "war of the currents".

Edison initially had the upper hand with his DC system, but Tesla and his AC system eventually emerged victorious, changing the history of electricity distribution forever. Below, I will cover in detail the key events, innovations, and factors leading to AC defeating DC.

Edison's DC System

Thomas Edison pioneered the first electricity distribution system in the late 1870s using direct current. At the time, DC was the only feasible way to distribute electricity commercially.

Advantages of Direct Current

By the early 1880s, Edison had established his DC electricity distribution via coal-fired generators and copper wiring across downtown New York City.

Limitations of Direct Current

However, DC systems had major limitations:

These limitations meant DC systems could only cover small areas. To expand electrification, extremely expensive parallel direct current systems would be needed.

Tesla's Breakthrough with Alternating Current

In 1884, Serbian inventor Nikola Tesla emigrated to the United States to work with Thomas Edison. However, Tesla soon struck out on his own to develop his ideas for alternating current (AC) electricity distribution.

Key Advantages of Alternating Current

Tesla's AC system had two major revolutionary benefits compared to Edison's DC:

Tesla's Induction Motor

In 1888, Tesla patented his most important breakthrough - the induction motor. This polyphase AC motor ran on alternating current and had a simple, rugged design.

Crucially, it did not use brushes and could operate directly off high voltage AC power. This made it far more efficient and practical than DC motors.

The induction motor moved Tesla's AC system from theory to reality. Tesla secured backing from George Westinghouse to commercialize AC electricity distribution.

The "War of the Currents"

The emergence of Tesla's AC system directly threatened Edison's DC monopoly. A fierce rivalry erupted between the two camps, known as the "war of the currents".

Edison Spreads Fear about AC

Edison launched a propaganda campaign against the dangers of high voltage AC power, killing animals publically using AC electricity to try and scare the public.

However, AC was rapidly becoming the favored choice for central power stations and longer transmission thanks to transformers. In 1893, the Niagara Falls hydroelectric project chose AC transmission over DC, dealing a major blow to Edison's system.

Victory of AC at the 1893 Chicago World's Fair

The clinching victory for AC occurred when Westinghouse underbid Edison for the lighting contract at the 1893 Chicago World's Fair. Westinghouse lit the entire fair and its 200,000 incandescent bulbs using AC.

This high profile demonstration displayed AC's economical advantages. Within a few years, AC had become the universal standard for electricity distribution worldwide.

Why AC Beat DC

In summary, AC beat DC in the war of the currents because of its major technical and economic advantages:

Legacy of the War of Currents

The widespread adoption of AC distribution enabled rapid national electrification and heralded the modern electric era. Despite losing the war of the currents, Edison's pioneering work with DC also played a crucial role in the early development of electricity supply networks.

However, it was Nikola Tesla's AC system that truly won the war of the currents and changed the world. AC allowed electricity to be transmitted anywhere, powering the electrification of homes, businesses, and industries across the United States and beyond. This system remains the standard for electricity distribution globally today.