Energy Transmission and Distribution Workers

Electricity was developed as a source of power during the 19th century, when a variety of technological advances made large-scale production of electricity feasible. The development of the first electric light bulb played an important role in the early growth of the electric power industry. Thomas Edison demonstrated his first carbon filament lamp in 1879, and by 1882, the first permanent, commercial electric power-generating plant and distribution network was established in New York City. Other generating plants and power line networks soon followed throughout Europe and America. These early systems proved to be inefficient at transmitting power over long distances because they used direct electric current, but generators that produced alternating current became practical in the 1890s. Many new uses for electric power were developed, and by the early 1900s, electric-powered devices were increasingly common in homes, businesses, and factories across the United States.

Other advances, such as the development of oil-insulated transformers, also contributed to delivering electric power over great distances. In 1914, it was possible to send 150,000 volts over aerial transmission lines. There were problems, however, in the underground transmission of power. Several procedures were tried and dismissed, but the development of lead-sheathed cable in 1925 made it possible to transmit more than 100,000 volts underground.

Today, electric power generated at central power stations is sent to substations, then on to consumers via overhead lines, underground and submarine cables, and microwave systems. At generating stations or nearby substations, voltages must be stepped up so that less power is lost through resistance as the electricity is transmitted over long distances. Transformers in substations at the end of long transmission lines must decrease voltage to levels that are suitable for distribution to users.

Digital technology is being developed to turn the power grid—the network of power lines that transmits electricity from generating plants to customers—into a smart grid. The U.S. Department of Energy reports that the smart grid "will consist of controls, computers, automation, and new technologies and equipment working together, but in this case, these technologies will work with the electrical grid to respond digitally to our quickly changing electric demand." The development of the smart grid will reduce the number of jobs that are available to power plant operators, distributors, and dispatchers in the future.