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Electrification Timeline


At the beginning of the 20th century, following a struggle between the direct-current systems favored by Thomas Edison and the alternating-current systems championed by Nikola Tesla and George Westinghouse, electric power was poised to become the muscle of the modern world. Today it keeps our factories running—as well as the telecommunications industry, the appliances in our homes, and the lifesaving equipment in our hospitals. In myriad other ways the ready access to electricity helps maintain the well-being of billions of people around the globe.

  1903   Steam Turbine Generator

The steam turbine generator invented by Charles G. Curtis and developed into a practical steam turbine by William Le Roy Emmet is a significant advance in the capacity of steam turbines.  Requiring one-tenth the space and weighing one-eighth as much as reciprocating engines of comparable output, it generates 5,000 kilowatts and is the most powerful plant in the world.

  1908   First solar collector

William J. Bailley of the Carnegie Steel Company invents a solar collector with copper coils and an insulated box.

  1910s   Vacuum light bulbs

Irving Langmuir of General Electric experiments with gas-filled lamps, using nitrogen to reduce evaporation of the tungsten filament, thus raising the temperature of the filament and producing more light. To reduce conduction of heat by the gas, he makes the filament smaller by coiling the tungsten.

  1913   Southern California Edison brings electricity to Los Angeles

Southern California Edison puts into service a 150,000-volt line to bring electricity to Los Angeles.  Hydroelectric Power is generated along the 233-mile-long aqueduct that brings water from Owens Valley in the eastern Sierra.

  1917   First long-distance high-voltage transmission line

The first long-distance high-voltage transmission line is established by American Gas & Electric (AG&E), an investor-owned utility.  The line originates from the first major steam plant to be built at the mouth of a coal mine, virtually eliminating fuel transportation costs.

  1920s   Windmills used to drive generators

Windmills with modified airplane propellers marketed by Parris-Dunn and Jacobs Wind are used to drive 1- to 3- kilowatt DC generators on farms in the U.S. Plains states. At first these provide power for electric lights and power to charge batteries for crystal radio sets, but later they supply electricity for motor-driven washing machines, refrigerators, freezers and power tools.

  1920s   First Plant to Reheat Steam

In Philo, Ohio, AG&E introduces the first plant to reheat steam, thereby increasing the amount of electricity generated from a given amount of raw material.  Soon new, more heat-resistant steel alloys are enabling turbines to generate even more power.

  1920s   High-pressure steam power plants

Boston Edison's Edgar Station becomes a model for high-pressure steam power plants worldwide by producing electricity at the rate of 1 kilowatt-hour per pound of coal at a time when generators commonly use 5 to 10 pounds of coal to produce 1 kilowatt-hour.  The key was operating a boiler and turbine unit at 1,200 pounds of steam pressure, a unique design developed under the supervision of Irving Moultrop. 

  1931   Introduction of bulk-power, utility-scale wind energy conversion systems

The 100-kilowatt Balaclava wind generator on the shores of the Caspian Sea in Russia marks the introduction of bulk-power, utility-scale wind energy conversion systems. This machine operates for about 2 years, generating 200,000 kilowatt-hours of electricity. A few years later, other countries, including Great Britain, the United States, Denmark, Germany, and France, begin experimental large-scale wind plants.

  1933   Tennessee Valley Authority

Congress passes legislation establishing the Tennessee Valley Authority (TVA). Today the TVA manages numerous dams, 11 steam turbine power plants, and two nuclear power plants. Altogether these produce 125 billion kilowatt-hours of electricity a year.

  1935   First generator at Hoover Dam begins operation

The first generator at Hoover Dam along the Nevada-Arizona border begins commercial operation. More generators are added through the years, the 17th and last one in 1961.

  1935   Rural Electrification Administration bring electricity to many farmers

President Roosevelt issues an executive order to create the Rural Electrification Administration (REA), which forms cooperatives that bring electricity to millions of rural Americans.  Within 6 years the REA has aided the formation of 800 rural electric cooperatives with 350,000 miles of power lines. 

  1942   Grand Coulee Dam completed

Grand Coulee Dam on the Columbia River in Washington State is completed. With 24 turbines, the dam eventually brings electricity to 11 western states and irrigation to more than 500,000 acres of farmland in the Columbia Basin.

  1953   Seven-state power grid

The American Electric Power Company (AEP) commissions a 345,000-volt system that interconnects the grids of seven states. The system reduces the cost of transmission by sending power where and when it is needed rather than allowing all plants to work at less than full capacity.

  1955   Nuclear power plant power entire town

On July 17, Arco, Idaho, becomes the first town to have all its electrical needs generated by a nuclear power plant. Arco is 20 miles from the Atomic Energy Commission’s National Reactor Testing Station, where Argonne National Laboratory operates BORAX (Boiling Reactor Experiment) III, an experimental nuclear reactor.

  1955   New York draws power from nuclear power plant

That same year the Niagara-Mohawk Power Corporation grid in New York draws electricity from a nuclear generation plant, and 3 years later the first large-scale nuclear power plant in the United States comes on line in Shippingport, Pennsylvania. The work of Duquesne Light Company and the Westinghouse Bettis Atomic Power Laboratory, this pressurized-water reactor supplies power to Pittsburgh and much of western Pennsylvania.

  1959   First large geothermal electricity-generating plant

New Zealand opens the first large geothermal electricity-generating plant driven by steam heated by nonvolcanic hot rocks. The following year electricity is produced from a geothermal source in the United States at the Geysers, near San Francisco, California.

  1959   First large geothermal electricity-generating plant

New Zealand opens the first large geothermal electricity-generating plant driven by steam heated by nonvolcanic hot rocks. The following year electricity is produced from a geothermal source in the United States at the Geysers, near San Francisco, California.

  1961   France and England connect electrical grids

France and England connect their electrical grids with a cable submerged in the English Channel. It carries up to 160 megawatts of DC current, allowing the two countries to share power or support each other’s system.

  1964   First large-scale magnetohydrodynamics plant

The Soviet Union completes the first large-scale magnetohydrodynamics plant. Based on pioneering efforts in Britain, the plant produces electricity by shooting hot gases through a strong magnetic field.

  1967   750,000 volt transmission line developed

The highest voltage transmission line to date (750,000 volts) is developed by AEP. The same year the Soviet Union completes the Krasnoyansk Dam power station in Siberia, which generates three times more electric power than the Grand Coulee Dam.

  1978   Public Utility Regulatory Policies Act

Congress passes the Public Utility Regulatory Policies Act (PURPA), which spurs the growth of nonutility unregulated power generation. PURPA mandates that utilities buy power from qualified unregulated generators at the "avoided cost"—the cost the utility would pay to generate the power itself. Qualifying facilities must meet technical standards regarding energy source and efficiency but are exempt from state and federal regulation under the Federal Power Act and the Public Utility Holding Company Act. In addition, the federal government allows a 15 percent energy tax credit while continuing an existing 10 percent investment tax credit.

  1980s   California wind farms

In California more than 17,000 wind machines, ranging in output from 20 to 350 kilowatts, are installed on wind farms. At the height of development, these turbines have a collected rating of more than 1,700 megawatts and produce more than 3 million megawatt-hours of electricity, enough at peak output to power a city of 300,000.

  1983   Solar Electric Generating Stations

Solar Electric Generating Stations (SEGs) producing as much as 13.8 megawatts are developed in California and sell electricity to the Southern California Edison Company.

  1990s   U.S. bulk power system evolves into three major grids

The bulk power system in the United States evolves into three major power grids, or interconnections, coordinated by the North American Electric Reliability Council (NERC), a voluntary organization formed in 1968. The ERCOT (Electric Reliability Council of Texas) interconnection is linked to the other two only by certain DC lines.

  1992   Operational 7.5- kilowatt solar dish prototype system developed

A joint venture of Sandia National Laboratories and Cummins Power Generation develops an operational 7.5-kilowatt solar dish prototype system using an advanced stretched-membrane concentrator.

  1992   Energy Policy Act

The Energy Policy Act establishes a permanent 10 percent investment tax credit for solar and geothermal powergenerating equipment as well as production tax credits for both independent and investor-owned wind projects and biomass plants using dedicated crops.

  2000   Semiconductor switches enable long-range DC transmission

By the end of the century, semiconductor switches are enabling the use of long-range DC transmission.


     1- Early Years
     2- Rural Electrification
     3 - AC or DC?
     4 - Power Generators
     5- Looking Forward
     Essay - E. Linn Draper, Jr.

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