AC vs. DC: Westinghouse, Edison, and the Electrification of America
Thomas Edison is widely known in the United States as perhaps the greatest inventor of all time: the creator of the light bulb, the phonograph, and the motion picture. However, in the battle to provide electrical power across America, he came out the loser to the designs of a Croatian immigrant named Nikola Tesla, a man little known outside the fields of science and engineering.
While studying engineering as a young man in Graz, Austria, during the late 1800s, Tesla realized the limitations of direct current (DC) as a method of transmitting electricity over distance. Invented by Edison in 1879, DC was quickly put to use, providing power to buildings in New York City and other urban centers, although its limitations soon became apparent. DC is so named because the current travels in only one direction. Because of the low voltage involved and the resistance in the wires through which the electricity is sent, it is nearly impossible to transmit DC over long distances. Consequently, generating stations were needed every few hundred feet, making DC useless outside of densely packed urban environments. While examining the problem Tesla, in a flash of inspiration, came up with the idea of using AC, or alternating current, which would utilize transformers to convert the current to high voltage for transmission over distances, and back to low voltage for use. Despite several years of working for companies in Europe, however, he was unable to convince anyone of the superiority of his system.
Immigrating to America in 1884, Tesla, who idolized Edison, sought work with the well-known inventor. Already committed to the idea of a DC system and unwilling to concede that Tesla's AC system might be superior, Edison nonetheless hired the 28-year-old Croatian and offered him a $50,000 bonus if he could boost DC generator efficiency by 25%. Tesla spent several months on the project, improving efficiency by 50%, only to have Edison claim that the bonus offer was a joke. Edison's actions proved to be the last straw in a series of disagreements between the two men, and Tesla quit to work on his own ideas. By the end of 1887, he had filed for seven patents, which taken together constituted a complete system for the commercial transmission and distribution of AC power. The inventor's hard work did not go unnoticed; the Pittsburgh industrialist George Westinghouse purchased the patents and hired Tesla to work on developing the system further. The war of the currents, as the battle between Edison's DC and Westinghouse's AC would come to be known, had begun.
Edison, perhaps realizing the superiority of the AC system, concentrated on discrediting AC by portraying it as a dangerous, even potentially lethal, method of delivering electricity. He hired a small-time inventor named Harold Brown to travel the country giving demonstrations, during which he would electrocute dogs and horses using AC to show that the system was unfit for commercial use. At the same time, the state of New York, looking for a safer, more humane method of executing its death row prisoners, came to Edison for recommendations. Sensing an opportunity, Edison didn't hesitate to recommend AC electricity as the best way to kill a man. In August 1890, Brown, using a Westinghouse AC generator, assisted authorities in executing the convicted ax murderer William Kemmler who became the first victim of the electric chair. The execution was far from humane, taking a total of eight minutes to achieve its end, and was described by The New York Times as "an awful spectacle, far worse than hanging."
Despite Edison's propaganda campaign, the advantages of an AC system were becoming apparent. The same year that Kemmler was "Westinghoused," as electrocution was labeled by critics, the Westinghouse Company built a 13-mile- (21-km-) long power line, transmitting electricity from the generators at Willamette Falls, Ore., to the city of Portland. The following year Westinghouse made history again by sending enough current over a 3-mile (5-km) distance to power a 100-horsepower ore crusher in Telluride, Colo., and in yet another milestone, Westinghouse installed a 100-mile- (160-km-) long AC line from Lauffen to Frankfurt, Germany. By 1892 Edison's company, Edison General Electric, had merged with the Thomson-Houston Company, which was already active in manufacturing and producing AC systems. Although he was named as a director of the resulting General Electric Company, Edison took little part in its activities.
The final blow to the DC system came at the 1893 Columbian Exposition in Chicago. Both General Electric and Westinghouse submitted proposals to provide the fair with electric lighting. General Electric's DC proposal carried a price tag of $1 million and brought with it a thick webbing of heavy copper wires. The Westinghouse bid, coming in at half the price, was chosen to light the fair, demonstrating the practicality and reliability of AC power. The war of the currents was over, and the course of industrial development throughout the world changed forever.
While studying engineering as a young man in Graz, Austria, during the late 1800s, Tesla realized the limitations of direct current (DC) as a method of transmitting electricity over distance. Invented by Edison in 1879, DC was quickly put to use, providing power to buildings in New York City and other urban centers, although its limitations soon became apparent. DC is so named because the current travels in only one direction. Because of the low voltage involved and the resistance in the wires through which the electricity is sent, it is nearly impossible to transmit DC over long distances. Consequently, generating stations were needed every few hundred feet, making DC useless outside of densely packed urban environments. While examining the problem Tesla, in a flash of inspiration, came up with the idea of using AC, or alternating current, which would utilize transformers to convert the current to high voltage for transmission over distances, and back to low voltage for use. Despite several years of working for companies in Europe, however, he was unable to convince anyone of the superiority of his system.
Immigrating to America in 1884, Tesla, who idolized Edison, sought work with the well-known inventor. Already committed to the idea of a DC system and unwilling to concede that Tesla's AC system might be superior, Edison nonetheless hired the 28-year-old Croatian and offered him a $50,000 bonus if he could boost DC generator efficiency by 25%. Tesla spent several months on the project, improving efficiency by 50%, only to have Edison claim that the bonus offer was a joke. Edison's actions proved to be the last straw in a series of disagreements between the two men, and Tesla quit to work on his own ideas. By the end of 1887, he had filed for seven patents, which taken together constituted a complete system for the commercial transmission and distribution of AC power. The inventor's hard work did not go unnoticed; the Pittsburgh industrialist George Westinghouse purchased the patents and hired Tesla to work on developing the system further. The war of the currents, as the battle between Edison's DC and Westinghouse's AC would come to be known, had begun.
Edison, perhaps realizing the superiority of the AC system, concentrated on discrediting AC by portraying it as a dangerous, even potentially lethal, method of delivering electricity. He hired a small-time inventor named Harold Brown to travel the country giving demonstrations, during which he would electrocute dogs and horses using AC to show that the system was unfit for commercial use. At the same time, the state of New York, looking for a safer, more humane method of executing its death row prisoners, came to Edison for recommendations. Sensing an opportunity, Edison didn't hesitate to recommend AC electricity as the best way to kill a man. In August 1890, Brown, using a Westinghouse AC generator, assisted authorities in executing the convicted ax murderer William Kemmler who became the first victim of the electric chair. The execution was far from humane, taking a total of eight minutes to achieve its end, and was described by The New York Times as "an awful spectacle, far worse than hanging."
Despite Edison's propaganda campaign, the advantages of an AC system were becoming apparent. The same year that Kemmler was "Westinghoused," as electrocution was labeled by critics, the Westinghouse Company built a 13-mile- (21-km-) long power line, transmitting electricity from the generators at Willamette Falls, Ore., to the city of Portland. The following year Westinghouse made history again by sending enough current over a 3-mile (5-km) distance to power a 100-horsepower ore crusher in Telluride, Colo., and in yet another milestone, Westinghouse installed a 100-mile- (160-km-) long AC line from Lauffen to Frankfurt, Germany. By 1892 Edison's company, Edison General Electric, had merged with the Thomson-Houston Company, which was already active in manufacturing and producing AC systems. Although he was named as a director of the resulting General Electric Company, Edison took little part in its activities.
The final blow to the DC system came at the 1893 Columbian Exposition in Chicago. Both General Electric and Westinghouse submitted proposals to provide the fair with electric lighting. General Electric's DC proposal carried a price tag of $1 million and brought with it a thick webbing of heavy copper wires. The Westinghouse bid, coming in at half the price, was chosen to light the fair, demonstrating the practicality and reliability of AC power. The war of the currents was over, and the course of industrial development throughout the world changed forever.
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