War of the currents
The war of the currents was a series of events surrounding the introduction of competing electric power transmission systems in the late 1880s and early 1890s. It grew out of two lighting systems developed in the late 1870s and early 1880s; arc lamp street lighting running on high-voltage alternating current (AC), and large-scale low-voltage direct current (DC) indoor incandescent lighting being marketed by Thomas Edison's company.[1] In 1886, the Edison system was faced with new competition: an alternating current system initially introduced by George Westinghouse's company that used transformers to step down from a high voltage so AC could be used for indoor lighting. Using high voltage allowed an AC system to transmit power over longer distances from more efficient large central generating stations. As the use of AC spread rapidly with other companies deploying their own systems, the Edison Electric Light Company claimed in early 1888 that high voltages used in an alternating current system were hazardous, and that the design was inferior to, and infringed on the patents behind, their direct current system.
This article is about the battle between electrical distribution methods. For the 2017 film, see The Current War.
In the spring of 1888, a media furor arose over electrical fatalities caused by pole-mounted high-voltage AC lines, attributed to the greed and callousness of the arc lighting companies that operated them. In June of that year Harold P. Brown, a New York electrical engineer, claimed the AC-based lighting companies were putting the public at risk using high-voltage systems installed in a slipshod manner. Brown also claimed that alternating current was more dangerous than direct current and tried to prove this by publicly killing animals with both currents, with technical assistance from Edison Electric. The Edison company and Brown colluded further in their parallel goals to limit the use of AC with attempts to push through legislation to severely limit AC installations and voltages. Both also colluded with Westinghouse's chief AC rival, the Thomson-Houston Electric Company, to make sure the first electric chair was powered by a Westinghouse AC generator.
By the early 1890s, the war was winding down. Further deaths caused by AC lines in New York City forced electric companies to fix safety problems. Thomas Edison no longer controlled Edison Electric, and subsidiary companies were beginning to add AC to the systems they were building. Mergers reduced competition between companies, including the merger of Edison Electric with their largest competitor, Thomson-Houston, forming General Electric in 1892. Edison Electric's merger with their chief alternating current rival brought an end to the war of the currents and created a new company that now controlled three quarters of the US electrical business.[2][3] Westinghouse won the bid to supply electrical power for the World's Columbian Exposition in 1893 and won the major part of the contract to build Niagara Falls hydroelectric project later that year (partially splitting the contract with General Electric). DC commercial power distribution systems declined rapidly in numbers throughout the 20th century; the last DC utility in New York City was shut down in 2007.