TESLA, WESTINGHOUSE AND EDISON ILLUMINATING COMPANY By this time, George Westinghouse was seeking for a solution to supply power over a long distance. He found Tesla’ s inventions very assuring and convincing and he believed that he could realize his target utilizing Tesla’ s inventions based on AC electrical systems. He offered 60,000 US dollars in cash and stock in the Westinghouse Corporation to Tesla in exchange for 18 of Tesla’ s patents.
Around seven years before Tesla, in January 1880, Edison set out to develop a company that would deliver the electricity to power and light the cities of the world. That same year, Edison established the Edison Illuminating Company, the first investor-owned electric utility, which later became the General Electric Corporation. In 1882, the Pearl Street generating station provided 110 volts of electrical power to 59 customers in lower Manhattan.
THE WAR OF CURRENTS The War of Currents is a series of events in which the world debated on electric power transmission systems in the late 1880s and early 1890s. Nikola Tesla and George Westinghouse( Westinghouse Electric Company) were promoting AC while Edison together with Edison Electric Light Company was promoting DC( Direct Current). In this war, Edison’ s party often employed very aggressive marketing practices which exaggerated the dangers of using AC – which Tesla championed in power transmission. These tricks aired a fear among the general public of the risk of accidental electrocution from high voltage AC leading to a question about its safety and regulation. One of the most infamous of these strategies was the 1903 electrocution of a circus elephant named Topsy in New York’ s Coney Island. Thus a long-lasting business feud over electrical power came into being.
However, New York City, being the battle ground for this war, had already invested in a number of Edison DC installations, and these of course continued to work for many years alongside the growing AC network. Unfortunately for Thomas Edison, the Westinghouse Corporation was chosen to supply power at the World’ s Columbian Exposition in Chicago, which was held in 1893. Two years later, in 1895, Tesla designed what was among the first AC hydroelectric power plants in the United States, at Niagara Falls. The following year, it was used to power the city of Buffalo, New York, a feat that was highly publicized throughout the world. But it wasn’ t until 1927 that New York decided to replace the DC equipment and it wasn’ t until 2007, just ten years ago that the last of the Edison DC installations was removed. With the outstanding success, AC power systems became the pre-eminent power system of the 20th century, and it has managed to secure its position as the worldwide standard ever since.
THE SPREAD OF AC OVER DC By the end of 1887, there were 121 DC based power stations and 68 alternating current power stations in the US. There was another competitor to Edison and Westinghouse emerging around the same time. Thomson-Houston Electric
Company, the third competitor was however arranging deals- coming to arrangements with Westinghouse which were unfavourable for Edison.
On the other hand, AC proved itself to be more adequate for transmitting power over long distances rather than DC. On technical grounds, the generation and distribution voltages of direct-current systems were the same. Due to this, DC systems had to employ large, thick wires to transmit power. Furthermore, the loads needed to be in close proximity with the plant and as a consequence, several plants had to be established even in a small geographical area. With the development of a practical transformer, alternating-current power could be sent long distances over relatively small wires at a conveniently high voltage. That voltage could then be stepped down to the level used by the customers. Alternating-current generating stations could be larger, however they were found more efficient and the distribution wires cost less than those of a DC power system. Hence AC won the battle of currents despite the fear that aired in the beginning.
WHAT IS HAPPENING NOW? IS IT AC OR DC? OR IS IT AC AND DC? While AC was found perfectly adequate for the conditions of the day, and for quite some long time in the 20th century, the changing needs of the 21st century have already started showing its limits. Even though Edison lost the battle in the beginning, the irony is that DC power systems are making its comeback just around the time that New York City finally got rid of all existing Edison DC installations.
The major advantage of DC power lines is their efficiency where a relatively less energy is lost as it is transmitted. Furthermore, there is no need for reactive power compensation along the line. Because DC flows steadily through the wires without changing direction many times each second and through the entire conductor rather than at the surface, Direct Current transmission lines typically lose less power than AC transmission lines. Moreover, a DC system can be used to link two asynchronous AC systems which make it even hygienic to be installed under existing conditions. The other advantage is the capability of a DC system to transmit power under water. It has no capacitive effects like the AC lines.
In a more practical point of view, today it is not quite a question of AC versus DC, but of AC and DC. As per this moment, a considerable amount of power is generated by renewable sources and rooftop panels are becoming a popular technology which produces DC. On the other hand, many of the devices we use run on DC. Mobile phones, computers and many other devices use an inbuilt rectifier to convert AC to DC. However it would be
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