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Alternative Energy Sources:

BIOFUELS

BIOMASS

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SOLAR ENERGY

WIND ENERGY

OCEAN ENERGY

HYDROELECTRIC

NUCLEAR ENERGY

 

 

Hydropower as Fuel

See also:

other readings with assessment in Alternative Energy -- Wind Energy -- Geothermal Energy -- Hydropower -- Nuclear Energy --

see Alternative Energy Basics


 

HYDROPOWER GENERATES ELECTRICITY

Of the renewable energy sources that generate electricity, hydropower is the most often used. It accounted for 6 percent of total U.S. electricity generation and 71 percent of generation from renewables in 2007.

It is one of the oldest sources of energy and was used thousands of years ago to turn a paddle wheel for purposes such as grinding grain.  Our nationís first industrial use of hydropower to generate electricity occurred in 1880, when 16 brush-arc lamps were powered using a water turbine at the Wolverine Chair Factory in Grand Rapids, Michigan. The first U.S. hydroelectric power plant opened on the Fox River near Appleton, Wisconsin, on September 30, 1882. Until that time, coal was the only fuel used to produce electricity. Because the source of hydropower is water, hydroelectric power plants must be located on a water source. Therefore, it wasnít until the technology to transmit electricity over long distances was developed that hydropower became widely used.

HOW HYDROPOWER WORKS

Image of the water cycle. Solar energy heats water on the surface, causing it to evaporate.

This water vapor condenses into clouds and falls back onto the surface as precipitation.

The water flows through rivers back into the oceans, where it can evaporate and begin the cycle over again.

Understanding the water cycle is important to understanding hydropower. In the water cycle -

  • Solar energy heats water on the surface, causing it to evaporate.
  • This water vapor condenses into clouds and falls back onto the surface as precipitation.
  • The water flows through rivers back into the oceans, where it can evaporate and begin the cycle over again.

    Mechanical energy is derived by directing, harnessing, or channeling moving water. The amount of available energy in moving water is determined by its flow or fall.Swiftly flowing water in a big river, like the Columbia River Image of how a hydropower plant works.
<p>The water flows from behind the dam through penstocks, turns the turbines, and causes the generators to generate electricity.
The electricity is carried to users by a transmission line.
Other water flows from behind the dam over spillways and into the river below.along the border between Oregon and Washington, carries a great deal of energy in its flow. So, too,with water descending rapidly from a very high point, like Niagara Falls in New York. In either instance, the water flows through a pipe, or penstock,then pushes against and turns blades in a turbine to spin a generator to produce electricity. In a run-of-the-river system, the force of the current applies the needed pressure, while in a storage system, water is accumulated in reservoirs created by dams, then released when the demand for electricity is high. Meanwhile, the reservoirs or lakes are used for boating and fishing, and often the rivers beyond the dams provide opportunities for whitewater rafting and kayaking. Hoover Dam, a hydroelectric facility completed in 1936 on the Colorado River between Arizona and Nevada, created Lake Mead, a 110-mile-long national recreational area that offers water sports and fishing in a desert setting.


    WHERE HYDROPOWER IS GENERATED

    Over one-half of the total U.S. hydroelectric capacity for electricity generation is concentrated in three States (Washington, California and Oregon) with approximately 27 percent in Washington, the location of the Nationís largest hydroelectric facility Ė the Grand Coulee Dam.

    It is important to note that only a small percentage of all dams in the United States produce electricity. Most dams were constructed solely to provide irrigation and flood control.

    HYDROPOWER AND THE ENVIROMENT

    Some people regard hydropower as the ideal fuel for electricity generation because, unlike the nonrenewable fuels used to generate electricity, it is almost free, there are no waste products, and hydropower does not pollute the water or the air. However, it is criticized because it does change the environment by affecting natural habitats. For instance, in the Columbia River, salmon must swim upstream to their spawning grounds to reproduce, but the series of dams gets in their way. Different approaches to fixing this problem have been used, including the construction of "fish ladders" which help the salmon "step up" the dam to the spawning grounds upstream.

SOURCE : ENERGY INFORMATION ADMINISTRATION -- DEPARTMENT OF ENERGY -- KIDS HOME PAGE

TEST YOUR KNOWLEDGE OF THE MATERIAL

Multiple Choice Questions

1. Which statement is correct about hydropower
a) it was used thousands of years ago to turn a paddle wheel for purposes such as grinding grain.
b) because the source of hydropower is water, hydroelectric power plants must be located on a water source
c) over one-half of the total U.S. hydroelectric capacity for electricity generation is concentrated in three States
d) all of the above are correct

2. One of the negative factors for using hydropower is:
a) Hydropower requires an expensive fuel
b) Hydropower causes moderate pollution
c) hydropower does change the environment by affecting natural habitats.
d) none of the above

3. The nations largest hydroelectric plant is located in which state?
a) Washington
b) California
c) Nevada
d) Oregon

4. Hydropower production can best be described as changes in energy...
a) Chemical --> Solar --> Electrical
b) Solar ---> Chemical ---> Electrical
c) Solar ---> Mechanical ---> Electrical
d) Mechanical ---> Solar ---> Electrical

5. Which statement is not true about the Water Cylce?
a) solar energy heats water on the surface, causing it to evaporate.
b) the amount of available energy in moving water is determined by the amount of rainfall in that area
c) water vapor condenses into clouds and falls back onto the surface as precipitation
d) water flows through rivers back into the oceans, where it can evaporate and begin the cycle over again

 

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