The North American power grid, consisting of five smaller grids, is said to be the largest machine ever created by mankind.
Power transmission lines in the US. Photo: Popular Science
The United States alone has 600,000 miles of transmission lines and 5.5 million miles of distribution lines. By all accounts, it’s an engineering feat, according to Popular Science . It’s grown from a small power station in New York City to a continent-spanning megaproject.
At 3 p.m. on September 4, 1882, an engineer working at a power station in midtown Manhattan turned on the switch. Within seconds, six 100-kilowatt DC generators, each weighing 27 tons and powered by coal, sputtered into life. Providing direct current (DC) power to residents within a 400-meter radius, Thomas Edison’s Pearl Street station was the first in the world to power 400 lamps for its initial 85 customers. This was the beginning of the American electrical grid.
Although the Pearl Street station ushered in a new era and Edison’s DC technology proved its worth, it could not be transmitted over long distances because engineers at the time could not increase the voltage after generating electricity. Because of this limitation, power stations had to be built as widely as mailboxes in cities and towns.
However, with the support of businessman George Westinghouse, another inventor and former Edison employee named Nikola Tesla, developed an induction motor using alternating current (AC) which was easier to manufacture and had less energy loss because its voltage could be increased/decreased by a transformer.
The competition between the two sides lasted until the late 1880s, with AC slowly gaining the upper hand. By the 1890s, a few AC generating stations in Colorado, Oregon, and California began transmitting electricity over long distances to residents. As the War of Currents drew to a close, power plants sprang up across the country, powering new inventions like the trolley.
The man who led the American electrical grid into the future was businessman Samuel Insull. When Insull arrived in Chicago in 1892, the city was getting its electricity from 20 different companies. After becoming president of the Chicago Edison Company, Insull quickly increased load factors, used more efficient steam turbines, and bought up other companies to convert rival power plants into transformer stations. Over the next 15 years, Insull acquired more than a dozen power plants and renamed the company Commonwealth Edison.
Many businesses quickly imitated Insull's success, raising concerns about monopoly power. The U.S. government established a number of local and federal regulatory agencies. The country became increasingly electrified, and President Franklin Roosevelt passed a series of policies to encourage competition and expand electricity to rural areas.
Finally, before World War II, the modern U.S. electrical grid began to take shape. To avoid blackouts, the federal government required cross-connections between electric companies. This meant that if the power went out in Boston, Massachusetts, electricity produced in Ohio could make up the shortfall. In the 1960s, the Eastern and Western grids provided the bulk of America’s electricity. While these two major grids were synchronized, there was little connection between them.
Throughout the 10th century, advances in DC voltage boosting and stepping down occurred. In 1990, the first large high-voltage direct current (HVDC) system began supplying power to New England. HVDC systems are more expensive because they require converters at both the power plant and the substation, but power can be transmitted farther and more efficiently than high-voltage AC (HVAC) systems. Today, HVDC is preferred when power needs to be transmitted over distances of nearly 400 miles.
An Khang (According to Popular Mechanics )
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