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  2. Hydropower - Wikipedia

    en.wikipedia.org/wiki/Hydropower

    Operators of hydroelectric stations compare the total electrical energy produced with the theoretical potential energy of the water passing through the turbine to calculate efficiency. Procedures and definitions for calculation of efficiency are given in test codes such as ASME PTC 18 and IEC 60041. Field testing of turbines is used to validate ...

  3. Hydroelectricity - Wikipedia

    en.wikipedia.org/wiki/Hydroelectricity

    Hydroelectric power stations continued to become larger throughout the 20th century. Hydropower was referred to as "white coal". [19] Hoover Dam's initial 1,345 MW power station was the world's largest hydroelectric power station in 1936; it was eclipsed by the 6,809 MW Grand Coulee Dam in 1942. [20]

  4. Pelton wheel - Wikipedia

    en.wikipedia.org/wiki/Pelton_wheel

    A wheel power divided by the initial jet power, is the turbine efficiency, η = 4u(V i − u)/V i 2. It is zero for u = 0 and for u = V i. As the equations indicate, when a real Pelton wheel is working close to maximum efficiency, the fluid flows off the wheel with very little residual velocity. [11]

  5. AP World History: Modern - Wikipedia

    en.wikipedia.org/wiki/AP_World_History:_Modern

    In 2012, the head of AP Grading, Trevor Packer, stated that the reason for the low percentages of 5s is that "AP World History is a college-level course, & many sophomores aren't yet writing at that level." 10.44 percent of all seniors who took the exam in 2012 received a 5, while just 6.62 percent of sophomores received a 5.

  6. History of electric power transmission - Wikipedia

    en.wikipedia.org/wiki/History_of_electric_power...

    Grand Rapids Electric Light & Power Company, established in March 1880 by William T. Powers and others, began operation of the world's first commercial central station hydroelectric power plant, Saturday, July 24, 1880, getting power from Wolverine Chair and Furniture Company's water turbine. It operated a 16-light Brush electric dynamo ...

  7. Armstrong effect - Wikipedia

    en.wikipedia.org/wiki/Armstrong_effect

    Armstrong Hydroelectric Machine. The Armstrong effect is the physical process by which static electricity is produced by the friction of a fluid. It was first discovered in 1840 when an electrical spark resulted from water droplets being swept out by escaping steam from a boiler.

  8. Low-head hydro power - Wikipedia

    en.wikipedia.org/wiki/Low-head_hydro_power

    Low-head hydro power refers to the development of hydroelectric power where the head is typically less than 20 metres, although precise definitions vary. [1] Head is the vertical height measured between the hydro intake water level and the water level at the point of discharge.

  9. Hydropower Regulatory Efficiency Act of 2013 - Wikipedia

    en.wikipedia.org/wiki/Hydropower_Regulatory...

    The Hydropower Regulatory Efficiency Act of 2013 is a Law that was introduced into the United States House of Representatives of the 113th United States Congress on January 15, 2013. It passed the House on February 13, 2013 by a vote of 422-0, [ 1 ] and then passed the Senate by unanimous consent on August 1, 2013. [ 2 ]