Back in the late 1800s, Thomas Edison promoted the use of direct current (DC) electricity by building a generating station in lower Manhattan to serve lighting loads in that area. An ex-employee of Edison's, Nikola Tesla, along with his new employer, George Westinghouse, competed with Edison by building a high-voltage alternating current (AC) system in Buffalo, NY. Shortly thereafter, AC won out over DC because, when distributing electricity over great distances, AC can be transformed to a higher voltage and distributed over much greater distances at a much lower cost than was the case when building a multitude of local DC generating stations.
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