Electrical Power Plants & Transmission

Because there are many electric motors located at long distances from the electric generators, which are located at power stations, the transfer of electrical energy between them is accomplished by a electrical circuit called a transmission system.   The voltage of the generator is increased and the current decreased by transformers.   (Power = Voltage x Current, so the power remains the same, allowing for small amounts dissipated as heat.)   This reduces the amount of heat generated by the current moving through the resistance of the wires.   Thus, 3,000 volts of the generator is transformed to 30,000 volts of the transmission lines, thus minimizing the loss.   At a transmission substation, the high 30,000 volts is reduced to, say, 1,000 volts.   This is further reduced to lower voltages (500, 440, 110, etc.) when delivered to factories, offices and homes.

To 1790

1790-1799

1800-1809

1810-1819

1820-1829

1830-1839

1840-1849

1850-1859

1860-1869

1870-1879

1880-1889

The nation's first hydroelectric plant, where the prime mover is a waterfall, is built at Appleton, WI, in 1881. ^{Carruth 333}

In January, 1882, Edison's Holborn Viaduct power station in London, UK, begins to supply direct current electricity for street lighting in New York City.  It will soon also provide lighting to private customers. ^{Singer 197-198}

On September 4, 1882, the first direct current electrical power plant with one "jumbo" generator is built on Pearl St., New York City, under the direction of Thomas A. Edison.   It services a business area within 1/4 mile, which will later be extended to 1/1 mile by increasing the voltage to compensate for line losses.   Its service area is limited by Edison's use of direct current (DC) instead of alternating current (AC) transmission, the former producing excessive line losses.   This system demonstrates the feasibility of the central electrical power station. ^{Finn 13}

The first alternating current power station begins operating in Buffalo, NY, on November 30, 1886, for supplying a few hundred incandescent lamps. ^{Singer 188}   The prime mover is a steam engine.

1890-1899

On October 4, 1890, excavation begins on the Niagara Falls power discharge tunnel, an unrecedented 24 feet in diameter, which will serve to release water from the powerhouses into the Niagara River. ^{Adams 6-7}

In 1893, Westinghouse Electric demonstrates a complete polyphase alternating current power system at the Chicago World's Fair.   It has a large 2-phase induction motor driven by the main polyphase AC generator, transformers to raise and lower the voltages and a short transmission line.   Small AC induction motors, a synchronous motor and a DC railway motor. ^{Singer 193}   This system provides substantial proof that a large AC power system is practical.

In October, 1893, Westinghouse Electric wins the contract to provide generators of the Tesla design and auxiliary equipment to the proposed Niagara Falls power station. ^{Adams 72}   The General Electric Co. receives the contract for transmitting and distributing the electricity.

In April, 1895, the first turbo-generator is tested and operated successfully at Niagara Falls. ^{Adams 39}

On August 26, 1895, Electrical power is delivered commercially to the Pittsburg Reduction Co. (later, the Aluminum Company of America) for reducing aluminum ores by electrolysis. ^{Adams 39}

On October 1, 1896, three 5000-hp turbo-generators are operational at Niagara Falls with demand for electricity exceeding supply. ^{Adams 39}

On November 15, 1896, Niagara Falls polyphase alternating current power is delivered to the Buffalo Railway Company in Buffalo, 22 miles away. ^{Adams 39}   This is the first time electricity is provided over such a long distance.   It was the achievement of an important commercial goal because at that time the city of Niagara Falls had a population of 5,000, whereas Buffalo had a population of 256,000.

1900-1909

1910-1919

1920-1929

1930-1939

On May 18, 1933, the Tennessee Valley Act becomes law to establish the Tennesee Valley Authority (TVA) to control Tennessee River floods, reforest the marginal lands, and provide rural electrification. ^{Carruth 484}

In 1936, Hoover Dam (Boulder Dam) becomes operational.   It provides hydroelectric power, flood control, and irrigation for many acres of farmland. ^{Carruth 495}

1940-1949

In 1942, the Grand Coulee Dam on the Columbia River in Washington State becomes operational.   It provids hydroelectric power, flood control, and irrigation for more than 1,000,000 acres of farmland. ^{Carruth 549}

1950-1959

1960-1969

1970-1979

1980-1989

1990-1999