© 2010 Board of Regents University of Nebraska The History of Electricity

© 2010 Board of Regents University of Nebraska

The History of Electricity


Electrical Discoveries•Natural occurrences of electricity:

•Lightning•Static-amber rods rubbed with cat fur•Electric fish (electric eels, electric catfish, others)•Nerve operation•Brain activity


Electrical Discoveries•Numerous scientists from 1600’s on started treating this as more than a curiosity•Benjamin Franklin’s kite experiment in 1752 proved lightning was electricity•Luigi Galvani in 1791 proved that electricity is what makes nerves work

Ben Franklin



Electrical Inventions•Electromagnetism united electricity and magnetism in 1819 (Orsted and Ampere)•Faraday invented the electric motor in 1821•1830’s: several inventors created the telegraph•Alexander Graham Bell invented the telephone in 1876•Thomas Edison invented the electric light bulb in 1879•Nikola Tesla invented Alternating Current

Thomas Edison


Nikola Tesla



Electrical Inventions•Whale oil, “town gas”, kerosene primary means of providing gas lights for many years prior to electricity•Widespread use of electricity to operate lights•Batteries•Electric vehicles•Enhanced and larger electric motors: AC and DC•Large generating systems: AC and DC


The Industrial Revolution•2nd half of the 1700’s through the 1800’s•Mechanization transformed modern society•Large industries sprang up, many powered by horses, then by steam engines•Agrarian farm life rapidly declined as farmers went to work in factories to earn better wages•Textiles, iron manufacturing, invention of concrete , all spurred growth in industrial systems


The Industrial Revolution•Prior to steam power, horse power and water power were the dominant forms of primary power for industry•Most fast-moving water was in New England states•Development of steam power opened up other areas of US for industrial development•Transportation changed dramatically thanks to steam-powered trains

Steam Locomotive



The War of the Currents: AC vs. DC•Edison promoted his Direct Current(DC) as the only “safe” way to deliver electricity to large populations•Westinghouse promoted Alternating Current (AC) as the only way to transport electricity over long distances•DC commercial power canonly be transported a few miles. •Edison invented large scale DC generators•Westinghouse bought patents for AC from Tesla

George Westinghouse



The War of the Currents: AC vs. DC•Edison started General Electric, later lost it to bankers•1882: Edison builds Pearl Street DC station in NYC•1894: Niagra Falls Power Company powered Buffalo, NY•Westinghouse/Tesla team eventually won the war of the currents•Today AC electricity can be transported 1000’s of miles by increasing the voltage at the generator to extreme levels


Electrical Distribution Begins

•Various frequencies of AC were tried. Settled on 60Hz•60Hz was used because of easy timing with clocks.•Also any frequency above about 40-50Hz makes flicker-free lighting: important in AC systems•Also higher frequencies would require faster spinning generators, creating mechanical challenges•1893: Westinghouse/Tesla system demonstrated AC at Chicago Exposition


1900’s: Electrical Distribution Begins

•Once an electrical power generating systems begins, all generators tied to that “grid” must be same frequency and phase•When loads increase demand for electricity, more generators must be added.•Numerous safeguards must be built in for safety and isolation of failures•First distribution systems were in cities where it was economical for the electric utilities to build and sell power to large customer bases


REA and TVA•Rural Electrification Administration•Tennessee Valley Authority•Great Depression of 1929•Public power vs. private (investor-owned) utilities hotly contested during 1920’s


REA and TVA•Prior to 1933, privately owned utilities refused to extend their service to rural areas, claiming lack of profitability•Private power companies set rural rates 4 times higher than city rates•Obviously, this was not perceived as a fair treatment of rural families


TVA•Tennessee Valley Authority•Federally-owned private corporation•Established in May 1933 to provide:

•Flood control•Navigation of waterways•Affordable electricity for rural communities•Fertilizer for more effective, productive farming•Economic development


TVA•Cover s most of Tennessee, parts of Alabama, Mississippi, Kentucky, a few other SE States.•Nation’s largest public power company•FDR campaigned on this issue during Presidential race: 1932•Nebraska Senator George Norris from McCook, NE partnered with Franklin Roosevelt to help establish public power entities•Red=dams; purple=nuclear power; yellow=fossil power

© 2010 Board of Regents University of Nebraska© 2010 Board of Regents University of Nebraska


REA•Rural Electrification Administration established 1935•Made loans available to local electric cooperatives to compete with big power companies•1930: 10% of rural homes had electricity•1940: 90% of rural homes had electricity


REA•PUHCA (Public Utility Holding Company Act): 1935

•Regulate electric utilities•Get control of private utilities

•REA has been reorganized (1994) and is now called RUS (Rural Utilities Service)•RUS is an agency of the United States Dept of Agriculture•RUS Tasked with providing to rural areas the following utilities:

•Electricity •Telephone•Water•Sewer


US Electrical Distribution Today

•Three separate grids:•Eastern interconnection•Western interconnection•Texas interconnection (ERCOT: Electric Reliability Council of Texas)

•Alaskan and some Canadian grids separate from the three main USA grids




•Reliability of each grid is critical •Each grid started independently at different times•Very little interconnection between the three grids

•60 Hz phase is different in each grid•Can not directly connect grids together•Must convert 60Hz AC to DC, then back to AC at the receiving grid’s phase



•Utility generators create 2300 to 30,000 volts•A transformer steps this voltage up to a higher voltage for long-distance transmission•When voltage is stepped up, current is stepped down•Some power is lost in the transformation of voltage/current•Numerous high voltage systems in use across North America

•765,000 volts 500,000 volts 345,000 volts 230,000 volts•138,000 volts 115,000 volts



•At various locations, sub-stations reduce the transmission voltage to more usable levels

•4000 volts – 69,000 volts•Final users get their power at lower voltages of 120-480 volts. •Transformers are used to change voltage levels, up and down. Only AC power can do this

Electrical Distribution System


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© 2010 Board of Regents University of Nebraska The History of Electricity