At the beginning of 1878, the famous American scientist and businessman Thomas Edison founded the Edison Electric Light company (now General Electric) and began to actively sell ... direct current. In 1880, he patented his system for the production and distribution of electricity, which included three wires - zero and ± 110 volts (this reduced the material consumption with the same energy losses). At the same time, Edison is actively improving the first electric bulbs, bringing their operating time to 1200 hours. It was then that Edison said his famous phrase: "We will make electric lighting so cheap that only the rich will burn candles" and began to implement it. By 1882, the company had launched the first power plants in London and Manhattan, and a few years later in the United States there were more than a hundred direct current power plants operating on a three-wire Edison system. But this is just a prehistory ...
In 1884, Thomas Edisson hires a young but very talented scientist Nicolas Tesla to refine DC generators, promising him $ 50, 000 (at that time, an amount approximately equivalent to $ 1 million today) if he succeeds in constructively improving electrical machines direct current, invented by Edison. However, after the successful completion of all the improvements, Edison refused to do this, joking that the emigrants did not understand American humor. After this statement, Tesla resigned, having worked at Edison Electric Light for about a year. Having received negative recommendations from his employer, Tesla was forced to interrupt for ancillary work for a whole year. However, soon friends lent him money, with which Tesla opened a company for the production of street lighting lamps and the inventor's business went uphill. Moreover, the company's office is located on Fifth Avenue, just near the headquarters of the company of the longtime abuser Edison. from that moment on, a century-old struggle broke out, known in America as the "War of currents"
DC power plants did not allow the transmission of large power to the consumer due to high losses. It was this shortcoming that Tesla noticed and set about developing an AC motor. Together with businessman Westinghouse, they start a large-scale campaign for the distribution of alternating current networks, which have shown themselves to be much more efficient than permanent ones. In retaliation, Edison went into black PR, publicly demonstrating the killing of animals with alternating current, and in 1887, Edison-funded engineer Harold Brown proposed the idea of killing criminals with current - of course, “dangerous” alternating current, not “safe” constant. Despite Edisson's best efforts, in 1891 a three-phase AC system was presented by a consortium led by AEG at an exhibition held in Frankfurt am Main. In 1893 Westinghouse won a tender to build a power plant at Niagara Falls. According to Tesla, "the capacity of the waterfall will be enough for the entire US." To reconcile Westinghouse and Edison, the latter got the construction of a power line leading from the power plant to Buffalo, the nearest major city. Tesla soon lost interest in this area and took up scientific research in the field of electromagnetic fields, leaving Westinghouse despite all the persuasions.
In the end, General Electric bought the Thomson-Houston AC machine company and began manufacturing them itself. Nevertheless, the anti-advertising of alternating current continued - in particular, Edison personally filmed the execution by electric shock of the elephant Topsy, who trampled three people and was killed for this in 1903.
Already at the beginning of the 20th century, most power plants supplied alternating current, there were many DC consumers. Alternating current for them was converted to direct current using mercury rectifiers. DC power plants were built until the 1920s. Helsinki finally switched to alternating current in the 1940s, Stockholm in the 1960s. Nevertheless, in the United States until the end of the 1990s, there were 4, 6 thousand scattered DC consumers, and in 1998, attempts began to convert them to alternating current.
In November 2007, a decision was made to terminate the supply of direct current through the networks and the chief engineer of Consolidated Edison, which was engaged in this, cut the symbolic cable. So the famous "war of currents" ended.