Thomas Edison was one of the most prolific inventors in history, responsible for breakthroughs like the phonograph, motion picture camera, and the first practical light bulb. However, one of Edison's inventions that truly changed the world was his system for electrical wiring and power distribution.
Edison's DC Power Networks Cause Sparks
In the late 1800s, Edison and his researchers at Menlo Park pioneered the generation and distribution of electricity using direct current (DC). At the time, DC power offered a major advantage over the alternatives - it could be transmitted over long distances using metal conductors.
Edison quickly established local DC power networks, the first being in New York City in 1882. These early systems used copper wiring to distribute 110 volts of DC power to homes and businesses from fossil fuel-powered generators and accumulators.
While revolutionary, Edison's DC networks had some major drawbacks:
- Low voltage - 110 volts severely limited the applications for electric power. Light bulbs and motors were about the only useful loads.
- Generation limits - DC power plants were restricted to within about 1 mile of customer loads. Longer distances resulted in excessive power losses in the copper lines.
- Dangerous - Exposure to 110 DC volts could easily result in electrocution.
These shortcomings led many to view Edison's technology as unsuitable for wider adoption.
Tesla and Westinghouse Introduce AC Power
Seeing the flaws in DC networks, inventor Nikola Tesla and industrialist George Westinghouse developed a competing alternating current (AC) system in the mid-1880s.
The key advantages of AC power included:
- Higher voltages - Transformers could be used to step up AC voltage for efficient transmission over long distances.
- Polyphase power - Generators could produce multiphase AC, allowing more power to be transmitted in a smaller conductor.
- Improved safety - While dangerous at ultra high voltages, low voltage AC was safer than DC at the same power level.
To prove the capabilities of AC, Tesla and Westinghouse constructed a demonstration hydroelectric plant at Niagara Falls in 1893, transmitting electricity to Buffalo over 15 miles away.
The War of the Currents
Edison was fiercely opposed to AC power and teamed up with Harold P. Brown to undertake an ugly PR and lobbying campaign to discredit Tesla and Westinghouse's technology. This came to be known as the War of the Currents.
Some of Edison's fear tactics included:
- Misinformation - Falsely claiming AC was significantly more deadly than DC at common voltages.
- Unethical demonstrations - Publicly electrocuting animals with AC to discourage adoption.
- Lobbying against AC - Pushing for legislation limiting AC installations in cities.
Edison's smear campaign culminated in Brown's development of the electric chair, touted as a demonstration of AC's lethal potential. Despite these efforts, AC proved superior and was rapidly adopted after the Niagara Falls project went live.
The Move to AC Power
In just over a decade after Niagara Falls, AC power had become the universal standard. Some key milestones included:
- 1895 - First commercial 3-phase AC power plant opens in Mill Creek, CA.
- 1896 - Hydroelectric dam at Niagara Falls starts supplying AC power to Buffalo, NY.
- 1900 - AC networks achieve transmission distances over 100 miles.
- 1920s - Virtually all urban power systems converted to AC.
AC Power Legacies
The shift to AC networks had profound and lasting impacts:
- Ubiquitous electricity - AC enabled reliable, affordable electricity access across entire cities and regions.
- High voltages - AC could be stepped up to hundreds of thousands of volts, enabling economical long-distance transmission.
- Interconnected grids - AC allowed local grids to be synchronized and connected into massive interstate power systems.
- Modernization - Availability of AC power drove mass electrification and productivity gains across industries.
Edison's Bitterness
Despite losing the War of the Currents, Edison remained an iconic figure and continued inventing into his 80s. However, he harbored bitterness against Tesla and AC power his entire life.
Some examples of Edison's lasting animosity include:
- Refusing to convert - Never electrifying his laboratory and home in Menlo Park with AC networks.
- Disparaging AC - Publicly dismissing AC as inferior and unsafe compared to his DC systems.
- Blocking commemorations - Strongly opposing proposals to honor Tesla and Westinghouse for contributions to electrification.
In the end, Edison had no choice but to live in an AC-powered world, although he never acknowledged defeat until his death in 1931. The War of the Currents and pervasiveness of AC systems cemented Tesla's critical role in shaping modern civilization.