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Teacher/Student Learning Packet
Hydroelectricity

CONCEPTS:

Generators can be powered by many sources. The most common sources are -- the wind; atomic fuels like uranium; gasoline or diesel engines; steam from fuels like oil, coal, or natural gas; and last but not least, water. Energy from water is created by the force of water flowing from a higher elevation -- usually from a reservoir or lake -- to a lower elevation, through a large pipe (penstock). When the flowing water reaches the end of the penstock it funnels into the scroll case where it hits and spins a water wheel (turbine).

A water turbine is a wheel with fins on it, somewhat like a windmill, except it uses water instead of air. Water hits and rotates the turbine, the turbine rotates the connecting shaft, which then turns the generator. Magnets spinning inside wire coils in the generator make the electricity. In this way the generator and turbine change mechanical energy into electrical energy. The electricity then flows by wires (transmission lines) to cities and homes where it is used.

After having done its job of turning the water turbines to generate electricity, the water flows downstream. There it can be stored behind dams and used again. Hoover Dam was built to make Lake Mead, from water flowing down the Colorado River. There are three other dams on the main stem of the Colorado River. The one 370 miles upriver from Lake Mead and north of the Grand Canyon is Glen Canyon Dam/Lake Powell. 67 miles south of Hoover Dam is Davis Dam/Lake Mojave. And 155 miles south of Hoover is Parker Dam/Lake Havasu.

There are over 53 dams on the Colorado River and its tributaries. All these dams use much of the same water and work together to control floods, irrigate crops, supply drinking water, make places for recreation, create habitat for wildlife, and of course -- generate electricity.

Bibliography

Hoover Dam: An American Adventure, Joseph Stevens, 1998. Univ. Of Oklahoma Press. 326 pgs. (excellent social history)

The Story of Hoover Dam. Nevada Publications. POB 15444, Las Vegas, NV 89114. 144 pgs. (informative series of technical magazine articles from 1931-36).

Construction of Hoover Dam. KC Publications. POB 94558, Las Vegas, NV 89193. 48 pgs. (basic booklet). Hoover Dam (video). Boulder City Historical Society and Museum, 444 Hotel Plaza, Boulder City, NV 89005. VHS, PAL, 1:00 min.

Last Reviewed: 9/16/2004