Hydroelectric Power=
Hydroelectric.jpeg
(Image retrieved from: www.fuelfromthewater.com/hydroelectric.htm)

History of hydroelectric power:

The name comes from "hydro", the Greek word for water http://www.darvill.clara.net/altenerg/hydro.htm [ASar8]
2,000 years ago greeks used water wheels to grind wheat into flour.([[http://ffdedn-2.phys.uaf.edu/104_spring2004.web.dir/Todd_Robyn/page5.htm)[SHer8]
1700's hydro-power was used for military lumber and pumping irrigation water.(http://ffdedn-2.phys.uaf.edu/104_spring2004.web.dir/Todd_Robyn/page5.htm.)[SHer8]1882 Appletown Wisconsin became the first operatianal hydro-electric generating station for the united states. (http://ffdedn-2.phys.uaf.edu/104_spring2004.web.dir/Todd_Robyn/page5.htm.) [SHer8]the invention of they hydraulic turbine made htdropower a sudden expansion. [[http://ffdedn- [SHer8]2.phys.uaf.edu/104_spring2004.web.dir/Todd_Robyn/page5.htm|(http://ffdedn- [SHer8]2.phys.uaf.edu/104_spring2004.web.dir/Todd_Robyn/page5.htm]].)in the 1900's 40% of the United States electricity was provided by hydro electric power. (http://ffdedn-2.phys.uaf.edu/104_spring2004.web.dir/Todd_Robyn/page5.htm.) [SHer8]Note to SHer8: just notifying a spell check in your history part. I believe you meant to say Greeks instead of geeks. I mean if that term existed back 200 years then thats cool. But just double check your work. [AAgu8]Note to Sher8: also check because I believe it was also 2,000 years ago that the Greeks did that. [RGov7]
  • Within the next 20 years, around the globe somewhere in the vacinity of 300 hydroelecric plants were operational. http://ffden-2.phys.uaf.edu/104_spring2004.web.dir/Todd_Robyn/Page5.htm [TCal8]
  • The first hydroelectric powerplant in the west was in San Bernardino, Ca. [TCal8]
  • In 1881 the street lamps were powered by hydropower from Niagara Falls. [TCal8]
  • In 1907, 15% of our generation of electicity in the United States came from Hydropower. [TCal8]
  • By 1940 this percentage hopped to 40% [TCal8]
  • The first federal Dam was located on the Columbia River, this was called the Bonneville Dam and begun operating in 1937. [TCal8]
http://www.fuelfromthewater.com/history.htm [TCal8]
  • The United States' first industrial use of hydroelectric power was the generating of electricity to power 16 brush-arc lamps at the Wolverine Chair Factory in Grand Rapids, Michigan in the year 1880. [SKoe8]
  • The first house in the world to be generated by hydroelctricity alone was the Cragside House, which was located in Northumberland, England, in the year 1878. [AAgu8]
http://home.clara.net/darvill/altenerg/hydro.htm
  • The tallest dam in the world that creates the biggest reserve of hydroelectricty is the Rogun dam in the country of Tajikistan. It stands at about 1000 feet tall. [AAgu8]
http://www.webmutations.com/energy/reports/present/rephydro.html

The following timeline is courtesy of Bechtel BWXT Idaho, LLC.
B.C., Used by the Greeks to turn water wheels for grinding wheat into flour, more than 2,000 years ago.
1775, U.S. Army Corps of Engineers founded, with establishment of Chief Engineer for the Continental Army.
1880, Michigan's Grand Rapids Electric Light and Power Company, generating electricity by dynamo, belted to a water turbine at the Wolverine Chair Factory, lit up 16 brush-arc lamps.
1881, Niagara Falls, city street lamps powered by hydropower.
1886, about 45 water-powered electric plants in the U.S. and Canada.
1887, San Bernardino, Ca., first hydroelectric plant in the west.
1889, 200 electric plants in the U.S. use waterpower for some or all generation.
1901, first Federal Water Power Act.
1902, Bureau of Reclamation established.
1907, 15% of electric generating capacity in U.S. was provided by hydropower.
By 1920, 25% of U.S. electrical generation was by hydropower. 1920, Federal Power Act establishes Federal Power Commission authority to issue licenses for hydrodevelopment on public lands.
1933, Tennessee Valley Authority established.
1935, Federal Power Commission authority extended to all hydroelectric projects built by utilities engaged in interstate commerce.
1937, Bonneville Dam, first Federal dam, begins operation on the Columbia River.
1937, Bonneville Power Administration established.
By 1940, 40% of electrical generation was hydropower.
Between 1921 and 1940, conventional capacity in the U.S. tripled; almost tripled again between 1940 and 1980.
Currently, about 7% of U.S. electricity comes from hydropower. Today, there is about 80,000 MW of conventional capacity and 18,000 MW of pumped storage
(http://www.fuelfromthewater.com/history.htm) [HSha2]


  • Water power was first harnessed in the northeast and soon used to power textile mills, sawmills and other simple machinery. Most of the American continent was settled first by locating a small dam and mill to provide the production necessary to drive a local economy. Many small towns still possess their own small mill ponds. It wasn't until the development of the generator in the 1880's that water-generated electricity became a viable use for the mill. The role of the generator and the new discovery of alternating current finally made hydro-electric power available to power street lights, homes and factories. (http://www.helium.com/items/1151635-what-happened-to-hydroelectric-power) [jgon2]

  • Hydropower converts the energy of flowing water into electricity or hydroelectricity. The amount of electricity generated is determined by the volume of water and the amount of "head" (the height from the turbines in the powerplant to the water surface) created by the dam. The greater the flow and head, the more electricity is produced.
  • The mechanical power of falling water is an age-old tool. Of all the renewable energy sources that generate electricity, hydropower is the most often used. 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. In the 1700's, mechanical hydropower was used extensively for milling and pumping. (http://inventors.about.com/library/inventors/bl_lester_pelton.htm)
  • [jgon2]
  • We have used running water as an energy source for thousands of years, mainly to grind corn.[jgon2]
The first house in the world to be lit by hydroelectricity was Cragside House, in Northumberland, England, in 1878. [jgon2]
In 1882 on the Fox river, in the USA, hydroelectricity produced enough power to light two paper mills and a house.[jgon2]
Nowadays there are many hydro-electric power stations, providing around 20% of the world's electricity. [jgon2]
The name comes from "hydro", the Greek word for water. (http://www.darvill.clara.net/altenerg/hydro.htm#more) [jgon2]

  • 1881- Niagra AFalls City street lamps powered by hydropower
  • 1882-First hydroelectic power plant was built in Appleton, Wisconsin, on the Fox River.
  • 1886-About 45 water-powered electic plants in the US and Canada
  • 1887-San Bernardino, California, opens first hydroelectic plain in the west
  • 1889-Two hundred electic plants in the US use waterpower for some or all generation
  • 1901-First Federal Water Power Act
  • 1907-Hydropower provides 15% of the US electrical generation
  • 1920-Hydropower provides 25% of the US electrical generation. Federal Power Act establishes Federal Power Commision authority to issue licenses for hydro developement on public lands
  • 1937-Bonnevill Dam, first Federal Dam, befins operation on the Columbia River.
  • 2003-About 10% of the US electricity comes from Hydropower [KCyw2]
http://wiki.answers.com/Q/What_is_the_history_of_hydroelectric_power

The concept of using a dam to carry water through turbine blades and then into a generator to produce the electricity was discovered by Michael Faraday in 1831 when he found that electricity could be generated by rotating magnets within copper coils. http://www.usbr.gov/power/edu/pamphlet.pdf [MMad7]

Over the past 100 years, the United States has led the world in dam building. Secretary of the Interior Bruce Babbitt recently observed that, 'on average, we have constructed one dam every day since the signing of the Declaration of Independence'. http://www.altenergy.org/renewables/hydroelectric.html [MMad7]


  • Hydropower has become the leading source of renewable energy. It provides more than 97% of all electricity generated by renewable sources worldwide. Other sources including solar, geothermal, wind, and biomass account for less than 3% of renewable electricity production. [MMad7]
  • In the US , 81% of the electricity produced by renewable sources comes from hydropower. [MMad7]
  • Worldwide, about 20% of all electricity is generated by hydropower. Some regions depend on it more than others. For example, 75% of the electricity produced in New Zealand and over 99% of the electricity produced in Norway come from hydropower. http://www.altenergy.org/renewables/hydroelectric.html [MMad7]

The Hoover Dam, also known as Boulder Dam, is a concrete gravity arts dam in the Black Canyon of the Colorado River. It is the second tallest dam in the United States. It is located on the border of U.S. states Arizona and Nevada and is 30 miles southeast of Las Vegas. [MMad7]
It is named after Herbert Hoover, who played an instrumental role in its construction first as the Secretary of Commerce and later as the President of the U.S. Construction. The dam ended up costing about $49,000,000. Construction began in 1931 and was completed in 1936, over 2 years ahead of schedule. [MMad7]
The dam was designated a national historic landmark in 1985. Generating 2080 Mega Watts, the dams power is spread throughout Arizona and Nevada, as well as 10 California cities, including Los Angeles.

http://www.darvill.clara.net/altenerg/hydro.htm#adv [MMad7]

For years, America's hydroelectric dams were hailed as symbols of progress, ingenuity and humankind's triumph over nature. Seemingly determined to leave no river untamed, government leaders and private companies built more than 100,000 dams during the 19th and 20th centuries. Today, of the major rivers in the lower 48 states, only the Yellowstone River still flows unimpeded, and the U.S. has more dams than every country in the world except China.
http://www.2facts.com/icof_story.aspx?PIN=i0502440&term=hydroelectric+energy [jgo2nd]


in 1995, all of Idaho's power came from hydroelectric plants.[MRec7]
http://ga.water.usgs.gov/edu/wuhy.html
By 1920, hydroelectric plants accounted for 40 percent of the electric power produced in the United States. [MRec7]
http://www.waterencyclopedia.com/Ge-Hy/Hydroelectric-Power.html

Hydropower is one of the oldest sources of energy. It was used thousands of years ago to turn a paddle wheel for purposes such as grinding grain. Our Nation's 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.
http://tonto.eia.doe.gov/kids/energy.cfm?page=hydropower_home-basics [ASar8]

The largest hydroelectric dam in the world is Rogun in Tajikistan. (11) It stands over 1000 feet tall. Hydroelectric energy is one of many energy sources used in the world[jgon2nd] http://www.webmutations.com/energy/reports/present/rephydro.html



Hydroelectric energy is a renewable energy source using the hydrologic cycle of water, which involves evaporation and the flow of water due to gravity. [jgon2nd]
http://www.totalsolarenergy.co.uk/hydroelectric-energy.html
Reliability of hydroelectric power:?

  • - unlike solar and wind power, hydroelectricity can be controlled, which means that we can choose when to use the right amount of power due to the fact that water is always there and that we don't have to wait for the sun to show or winds to be prevelant. [AAgu8]
    http://www.howtopowertheworld.com/advantages-of-hydroelectric-energy.html
  • A big advantage of hydroelectric power is that its a renewable resource, unlike fossil fuels that take thousands of years to develop, water is everywhere and quantity does not matter. http://ga.water.usgs.gov/edu/hydroadvantages.html [TCal8]
  • 96% of our nations renewable energy comes from hydropower. http://www.usbr.gov/power/edu/pamphlet.pdf [TCal8]
  • Hydroelectricity uses the energy of running water, without reducing its quantity, to produce electricity. All hydroelectric products, of small or large size, whether run of the river or of accumulated storage, fit the concept of renewable energy. (http://ga.water.usgs.gov/edu/hydroadvantages.html) [RGov7]
  • River water is a domestic resource which, contrary to fuel or natural gas, is not subject to market fluctuations. In addition to this, it is the only large renewable source of electricity and its cost-benefit ratio, efficiency, flexibility and reliability assist in optimizing the use of thermal power plants. (http://ga.water.usgs.gov/edu/hydroadvantages.html) [RGov7]
  • Hydroelectric power plants don't release pollutants into the air. They very frequently substitute the generation from fossil fuels, thus reducing acid rain and smog. In addition to this, hydroelectric developments don't generate toxic by-products. (http://ga.water.usgs.gov/edu/hydroadvantages.html) [RGov7]
the worlds largest renewable source of electricity accountiting for 6% of world wide energy supply or about 15% of the world's electricity. cheap, and clean source.
(http://ondix.com/pdf/docs/sample_essay_1071167929.pdf)
[SHer8]

  • More reliable than most other forms of electricity. Water flows down hill. As long as the lakes and rivers that are feeding the hydroelectric station don't dry up, they will always generate electricity. You will never run out of gas or uranium or coal to power the plant. [KCyw2]
http://wiki.answers.com/Q/Is_hydroelectric_power_reliable


Hydropower is an essential contributor in the national power grid because of its ability to respond quickly to rapidly varying loads or system disturbances, which base load plants with steam systems powered by combustion or nuclear processes cannot accommodate. http://www.usbr.gov/power/edu/pamphlet.pdf [MMad7]

Reclamation, the second largest supplier of wholesale water and hydroelectric power in the American West, owns 58 powerplants throughout the Western United States that produce an average of 42 billion kWh (kilowatt-hours) per year, enough to meet the residential needs of more than 14 million people. [MMad7]
This is the electrical energy equivalent of about 72 million barrels of oil. Hydroelectric powerplants are the most efficient means of producing electric energy, and as their efficiency coincides with their ability to be renewed easily and without pollution, this form of energy is also extremely reliable. http://www.usbr.gov/power/edu/pamphlet.pdf [MMad7]


17% of the total number of power generating
units in the United States and Canada.
According to a North American Electric
Reliability Council (NERC) Generating
Availability Report, failures of the wicket gate
mechanism, turbine governor, generator
bearings and lube oil system are among the
top 25 causes of forced and scheduled outages
and deratings of hydroelectric turbines.This
There are two categories of hydroelectric
turbines:Impulse and Reaction. Impulse
turbines are driven by one or more water jets
directed tangentially into “buckets”or “paddles”
of a wheel-shaped runner turning in air.
Reaction turbines are completely immersed in
water,and are driven by the difference in water
pressure between the pressure side and the
discharge side of the runner blade — much like
a windmill propeller is driven by the w [jgo2] http://www.pall.com/pdf/PGHYDEN.pdf

Advocates of hydroelectric energy have vehemently denounced environmentalists' calls for the demolition of dams. With the costs of traditional fuel--particularly oil--on the rise, supporters argue, the U.S. should be working to improve, rather than dismantle, hydroelectric dams. Taking down dams would only increase the U.S.'s reliance on foreign sources of crude oil, and threaten American farms, manufacturers and shipping companies who need dams for irrigation and water transportation, supporters say. Many leaders have also called on the federal government to loosen its regulation of hydroelectric energy to give private interests greater freedom to construct and maintain dams.
http://www.2facts.com/icof_story.aspx?PIN=i0502440&term=hydroelectric+energy [jgo2nd]

Hydro power relies on the water cycle http://tonto.eia.doe.gov/kids/energy.cfm?page=hydropower_home-basics [ASar8]

How is hydroelectric power used?:

    • Hydroelectric power is used to provide power for cities or certain areas that are near the said dam. as in case for Ontario, half of their power is produced by the process of Hydroelectricity. [AAgu8]
http://home.clara.net/darvill/altenerg/hydro.htm
    • Some Hydroelectric power plants even have the ability to store energy. These are known as Pumped storage plants. The power is sent from the grid into the generators. The generators spin the turbines backwards, which makes the turbines pump water from a low reservoir to an upper reservoir. This water is then released to the turbines, spinning them forward and activating the generators which will produce electricity. [AAgu8]
http://www.oilprice.com/article-Hydroelectric-Energy-Explained.htm
w
  • Huge power generators are placed inside dams. Water flowing through the dams spin turbine blades which are connected to generators. Power is produced and is sent to homes and businesses. (http://ga.water.usgs.gov/edu/wuhy.html ) [RGov7]

Hydroelectric_dam_diagram.png[HSha2]

  • he damming of streams and rivers has been an integral part of human civilization from its early history. Controversy paralleled this use because impounding and diverting water for upstream users affects those who live downstream, and also modifies the local habitats of plants and animals. Dams are built to control floods, improve navigation, provide a drinking-water supply, create or enhance recreational opportunties, and provide water for irrigation and other agricultural uses. A small percentage of dams (less than 3 percent in the United States) are used to generate power. (Atkins, William Arthur. "Hydroelectric Power." Water: Science and Issues. Ed. E. Julius Dasch. Vol. 2. New York: Macmillan Reference USA, 2003. 187-191. 4 vols. Gale Virtual Reference Library. Gale. BARRINGTON HIGH SCHOOL. 3 Nov. 2009) [RGov7]
  • Hydroelectric Power is a clean source of renewable energy where an adequate water source is readily available. Hydropower plants provide inexpensive electricity without environmental pollution such as air emissions or waste byproducts. And, unlike other energy sources such as fossil fuels, water is not consumed during electrical production, but can be reused for other purposes. (Atkins, William Arthur. "Hydroelectric Power." Water: Science and Issues. Ed. E. Julius Dasch. Vol. 2. New York: Macmillan Reference USA, 2003. 187-191. 4 vols. Gale Virtual Reference Library. Gale. BARRINGTON HIGH SCHOOL. 3 Nov. 2009) [RGov7]
  • The simple design of hydroelectric plants allows for inexpensive repair and maintenance cost. [SKoe8] http://drake.marin.k12.ca.us/stuwork/rockwater/Upload%20this%20doc--dams%20and%20hydropower%20report/pros%20and%20cons.html
  • Hydroelectric power plants are usually automated and need a small amount of workers to run them. [SKoe8] http://www.alternativeenergysecret.com/hydroelectric-energy.html
  • Hydroelectric plants can function properly for a very long time. [SKoe8] http://hubpages.com/hub/facts-about-hydroelectric-energy
  • Dams prevent floods from occurring. [SKoe8] http://www.webmutations.com/energy/reports/present/rephydro.html
  • Hydroelectric is a clean, non-polluting type of energy. [SKoe8] http://www.webmutations.com/energy/reports/present/rephydro.html

  • Hydroelectric power has a very stable price, it doesnt go up and down depending on the market like fuels and natural gases. [TCal8]
  • Hydroelectric power plant reservoirs help in storing drinking water because they collect rain, this in turn reduces chances of floods and droughts. [TCal8]
  • Its renewable, clean, and could be prevent floods. (http://www.webmutations.com/energy/reports/present/rephydro.html) [jgon2]
http://ga.water.usgs.gov/edu/hydroadvantages.html [TCal8]
the blockage of streams and rivers has been an intergral part of human civalization from it's early history.(http://www.waterencyclopedia.com/Ge-hydroelectic-power. html) [SHer8]

controversy paralleled this use because impounding and diverting water for upstram users affects downstrem, also modifies local habitats of plants and animals. (http://www.waterencyclopedia.com/Ge-hydroelectic-power. html)
[SHer8]

dams are built to control floods, improve naviation, provide a water supply fro drinking, create or enhance recreational oppertunities. (http://www.waterencyclopedia.com/Ge-hydroelectic-power. html)
[SHer8]

it can also provid water for irragation and other agricultural uses! [SHer8]
(http://www.waterencyclopedia.com/Ge-hydroelectic-power. html)
[SHer8]

  • Hydropower is used to produce more electricity than other renewable methods of electricity generation in the U.S., according to the Energy Information Administration. This means that its use is more widespread than that of wind or solar power. [KCyw2]
http://hubpages.com/hub/facts-about-hydroelectric-energy


Hydroelectric power supplies about 19% of the world’s electricity.[MRec7]

http://www.beyondfossilfuel.com/hydroelectric/

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 as needed to generate electricity.
http://tonto.eia.doe.gov/kids/energy.cfm?page=hydropower_home-basics [ASar8]




A dam is built to trap water, usually in a valley where there is an existing lake.
Water is allowed to flow through tunnels in the dam, to turn turbines and thus drive generators.
Notice that the dam is much thicker at the bottom than at the top, because the pressure of the water increases with depth.
Hydro-electric power stations can produce a great deal of power very cheaply.[jg2nd]


What are the benefits of using Hydroelectric Power?

long-term renewable resourse influenced by the sun's energy

nature provides water to run the power plant. [SHer8]
non-polluting. flood control. in case of a drought, a dam will still supply water. [SHer8]
90% efficency, unlike fossil fules with 30-40%.[SHer8]
storing energy for purpose of industrial, agricultural, or reactional reasons.[SHer8]
reliable, and qwick reacting changes in public demand. cost efficent.[SHer8]
low opperating and maintanence expenses. lifespan of 50-70 years for large facilities. [SHer8]
able to develop third world nations to a more modern and advanced society.[SHer8]

(http://ffden-2.phys.uaf.edu/104_spring2004.web.dir/Todd_Robyn/page5)

.htm. [SHer8]

Advantages of Hydroelectric Power Production and Usage [HSha2]
Representatives of more than 170 countries reached consensus at the Top World Conference on Sustainable Development, in Johannesburg (2002), and at the 3rd World Forum on Water, in Kyoto (2003): all hydroelectric generation is renewable and merits international support. Read, below, the ten reasons leading them to this conclusion.
1. Hydroelectricity is a renewable energy source.
Hydroelectricity uses the energy of running water, without reducing its quantity, to produce electricity. Therefore, all hydroelectric developments, of small or large size, whether run of the river or of accumulated storage, fit the concept of renewable energy. [HSha2]

2. Hydroelectricity makes it feasible to utilize other renewable sources.
Hydroelectric power plants with accumulation reservoirs offer incomparable operational flexibility, since they can immediately respond to fluctuations in the demand for electricity. The flexibility and storage capacity of hydroelectric power plants make them more efficient and economical in supporting the use of intermittent sources of renewable energy, such as solar energy or Aeolian energy. [HSha2]

3. Hydroelectricity promotes guaranteed energy and price stability.
River water is a domestic resource which, contrary to fuel or natural gas, is not subject to market fluctuations. In addition to this, it is the only large renewable source of electricity and its cost-benefit ratio, efficiency, flexibility and reliability assist in optimizing the use of thermal power plants. [HSha2]

4. Hydroelectricity contributes to the storage of drinking water.
Hydroelectric power plant reservoirs collect rainwater, which can then be used for consumption or for irrigation. In storing water, they protect the water tables against depletion and reduce our vulnerability to floods and droughts. [HSha2]

5. Hydroelectricity increases the stability and reliability of electricity systems.
The operation of electricity systems depends on rapid and flexible generation sources to meet peak demands, maintain the system voltage levels, and quickly re-establish supply after a blackout. Energy generated by hydroelectric installations can be injected into the electricity system faster than that of any other energy source. The capacity of hydroelectric systems to reach maximum production from zero in a rapid and foreseeable manner makes them exceptionally appropriate for addressing alterations in the consumption and providing ancillary services to the electricity system, thus maintaining the balance between the electricity supply and demand. [HSha2]

6. Hydroelectricity helps fight climate changes.
The hydroelectric life cycle produces very small amounts of greenhouse gases (GHG). In emitting less GHG than power plants driven by gas, coal or oil, hydroelectricity can help retard global warming. Although only 33% of the available hydroelectric potential has been developed, today hydroelectricity prevents the emission of GHG corresponding to the burning of 4.4 million barrels of petroleum per day worldwide. [HSha2]

7. Hydroelectricity improves the air we breathe.
Hydroelectric power plants don't release pollutants into the air. They very frequently substitute the generation from fossil fuels, thus reducing acid rain and smog. In addition to this, hydroelectric developments don't generate toxic by-products. [HSha2]

8. Hydroelectricity offers a significant contribution to development.
Hydroelectric installations bring electricity, highways, industry and commerce to communities, thus developing the economy, expanding access to health and education, and improving the quality of life. Hydroelectricity is a technology that has been known and proven for more than a century. Its impacts are well understood and manageable through measures for mitigating and compensating the damages. It offers a vast potential and is available where development is most necessary. [HSha2]

9. Hydroelectricity means clean and cheap energy for today and for tomorrow.
With an average lifetime of 50 to 100 years, hydroelectric developments are long-term investments that can benefit various generations. They can be easily upgraded to incorporate more recent technologies and have very low operating and maintenance costs. [HSha2]

10. Hydroelectricity is a fundamental instrument for sustainable development.
Hydroelectric enterprises that are developed and operated in a manner that is economically viable, environmentally sensible and socially responsible represent the best concept of sustainable development. That means, "development that today addresses people's needs without compromising the capacity of future generations for addressing their own needs" (World Commission on the Environment and Development, 1987). [HSha2]
http://ga.water.usgs.gov/edu/hydroadvantages.html

  • fuel is not burned so there is minimal pollution
external image blcolball.gif Water to run the power plant is provided free by nature
  • external image blcolball.gif Hydropower plays a major role in reducing greenhouse gas emissions
  • external image blcolball.gif Relatively low operations and maintenance costs
  • external image blcolball.gif The technology is reliable and proven over time
  • external image blcolball.gif It's renewable - rainfall renews the water in the reservoir, so the fuel is almost always there

(http://ga.water.usgs.gov/edu/wuhy.html) [jgon2]

http://ffden-2.phys.uaf.edu/104_spring2004.web.dir/Todd_Robyn/page5
    • another advantage is also that with dams created since the flow of water can never stop, the electricity created from the dams is always constant and will not stop unless there is a drought of water or a dam malfunction. [AAgu8]
    • unlike other forms of energy, hydroelectric is one of the few rare renewable forms of energy. The sun will always provide water with the process of evaporation. [AAgu8]
http://home.clara.net/darvill/altenerg/hydro.htm
    • Using this type of energy is not dependent on the prices of Uranium, Oil or other types of fuel, This will make the electricity costs much more fluid and stable. [AAgu8]
http://hubpages.com/hub/advantages-hydroelectric-power
  • It can fit to almost any size valley and river, but also can power as much as cities, factories, large towns or even the average home far from electrical, generators reach. [AAgu8]
http://hubpages.com/hub/advantages-hydroelectric-power


  • No waste or pollution produced.
http://home.clara.net/darvill/altenerg/hydro.htm [MRec7]
  • Water can be stored above the dam ready to cope with peaks in demand.
http://home.clara.net/darvill/altenerg/hydro.htm [MRec7]
  • Hydro-electric power stations can increase to full power very quickly, unlike other power stations.
http://home.clara.net/darvill/altenerg/hydro.htm [MRec7]
  • Electricity can be generated constantly.
(http://home.clara.net/darvill/altenerg/hydro.htm)[MRec7]

Hydropower represents 19% of total electricity production. [MRec7]
http://ga.water.usgs.gov/edu/wuhy.html




http://www.darvill.clara.net/altenerg/hydro.htm
Electricity can be generated constantly. http://www.darvill.clara.net/altenerg/hydro.htm [RGov7]
Advantages
      • Inexhaustible fuel source
      • Minimal environmental impact
      • Viable source--relatively useful levels of energy production
      • Can be used throughout the world [KCyw2]

    • It is renewable, clean, non-polluting, and it prevents floods. Not all dams produce electricity, but they prevent flooding, and others do both. [KCyw2]
http://www.webmutations.com/energy/reports/present/rephydro.html


    • The major advantage of hydroelectricity is elimination of the cost of fuel. The cost of operating a hydroelectric plant is nearly immune to increases in the cost of fossil fuels such as oil, natural gas or coal, and no imports are needed. [MMad7]
    • Hydroelectric plants also tend to have longer economic lives than fuel-fired generation, with some plants now in service which were built 50 to 100 years ago.[4] Operating labor cost is also usually low, as plants are automated and have few personnel on site during normal operation. [MMad7]
    • It has been calculated that the sale of electricity from the Three Gorges Dam will cover the construction costs after 5 to 8 years of full generation. [MMad7]
http://en.wikipedia.org/wiki/Hydroelectricity#Advantages



In 2004, these renewables, including biofuels for transport, accounted for around 13% of total world primary energy demand.
http://find.galegroup.com/ovrc/retrieve.do?subjectParam=Locale%2528en%252C%252C%2529%253AFQE%253D%2528su%252CNone%252C19%2529hydroelectric%2Bpower%2524&contentSet=GSRC&sort=Relevance&tabID=T010&sgCurrentPosition=0&subjectAction=DISPLAY_SUBJECTS&prodId=OVRC&searchId=R1&currentPosition=2&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale%28en%2C%2C%29%3AFQE%3D%28SU%2CNone%2C19%29hydroelectric+power%24&inPS=true&searchType=BasicSearchForm&displaySubject=&docId=EJ3010132275&docType=GSRC[ASar8]
      • Disadvantages of using hydroelectric power











damges caused by flooding above dams. migratory travel is restricted with structure. (http://ffden-2.phys.uaf.edu/104_spring2004.web.dir/Todd_Robyn/page5.htm)
. [SHer8]
plant/animal habitats will be destroyed. water areas may dry up.(http://ffden-2.phys.uaf.edu/104_spring2004.web.dir/Todd_Robyn/page5.htm)
. [SHer8]
only 3% of the nations 80,000 dams generates hydroelectric power. high initial construction costs.(http://ffden-2.phys.uaf.edu/104_spring2004.web.dir/Todd_Robyn/page5.htm)
. [SHer8]



Most of the water provided by dams is lost due to inefficient agricultural irrigation.[SKoe8]
Globally this causes 1,500 trillion liters of water to be wasted.[SKoe8] http://www.panda.org/what_we_do/footprint/water/dams_initiative/
Dams, in certain situations, can cause people to be forced from their homes.[SKoe8]
Many Dams are old and inefficient [SKoe8] http://www.panda.org/what_we_do/footprint/climate_carbon_energy/energy_solutions/renewable_energy/clean_energy_facts/hydro_energy_facts/
Location is the biggest issue of where you can collect hydroelectric energy. You have to build the generators and dams in areas of valleys and rivers where water has a everflowing current. It has to a significant area for it to really take effect. [AAgu8]
http://www.webmutations.com/energy/reports/present/rephydro.html
    • With the creation of the dams, it creates more of a lake habitat for species, while this may seem to have no effect this has effected the fish species coho, chinook, and sockeye salmon in which they have no migration path when the dams are built. The percentage of fish making the migration path has dropped 90%. [AAgu8]
http://www.ucsusa.org/clean_energy/technology_and_impacts/energy_technologies/how-hydroelectric-energy.html
    • The damage of breakage in dams is also a mojor concern. Although it is a ocassional occurance, the damages from a dam rupturing and breaking are monuemental. If the dam was close in area of tectonic plates underneath the earths surface, earthquakes can also further damage the dam if not properly prepared. [AAgu8]
[[http://www.ucsusa.org/clean_energy/technology_and_impacts/energy_technologies/how-hydroelectric-energy.html |http://www.ucsusa.org/clean_energy/technology_and_impacts/energy_technologies/how-hydroelectric-energy.html]]

  • Hydroelectric dams can harm many species that live on the area, the land around the dam can be destroyed, and the furious turbines will kill the fish.[KCyw2]
http://www.webmutations.com/energy/reports/present/rephydro.html

  • Very high capital cost or investment: The initial cost of the construction of the hydroelectric power plants is very high.[KCyw2]
  • High quality construction: The construction materials used for the construction of the dams should be of high quality.[KCyw2]
  • Site specific: The hydroelectric power plants cannot be constructed at any locations. [KCyw2]
  • Affects on environment: Though the hydroelectric power plants do not require any fuel, don’t produce greenhouse gases and don’t create pollution directly, it does have a number of detrimental affects on the environment.[KCyw2]
  • Safety of the dams: The safety of the dams is very crucial as it can affect lives of millions of people.[KCyw2]
http://www.brighthub.com/engineering/mechanical/articles/7730.asp




  • The dams are very expensive to build. However, many dams are also used for flood control or irrigation, so building costs can be shared. [MMad7]
  • Building a large dam will flood a very large area upstream, causing problems for animals that used to live there. [MMad7]
  • Finding a suitable site can be difficult - the impact on residents and the environment may be unacceptable. [MMad7]
  • Water quality and quantity downstream can be affected, which can have an impact on plant life.
http://www.darvill.clara.net/altenerg/hydro.htm#adv [MMad7]

In some cases, changes in reservoir and stream water quality[MRec7]

Economic costs of using hydroelectric power:

      • Hydroelectric Power is known as a very cheap and clean resource. There is a very low running cost for a plant and don't require many workers which means less jobs to pay for.
http://peter.mapledesign.co.uk/writings/physics/2005_Hydroelectric_Power_Feasible_or_Desirable.pdf
      • In comparing hydropower to other energy generators, the other generators take less time to design, obtain approval, build and recover investment. However, they have higher operating costs and typically shorter operating lives (about 25 years). [HSha2]
      • A hydropower plant has a high capital cost but maintenance costs are only minimal when looking at some other sources of energy production. The plant life can be extended economically by relatively cheap maintenance and the periodic replacement of equipment (replacement of turbine runners, rewinding generators, etc). Typically a hydro plant in service for 40 - 50 years can have its operating life doubled. [HSha2]
      • Comparing the cost of electricity with the initial investment of a hydropower system, the pay back period is short. Theoretically, a hydro plant should be able to produce electricity for a fixed amount during the life span of the unit. The operating costs should not change because there is no associated price to the water. Unlike in fossil fuel plants, the price of natural gas, coal, etc. fluctuates depending on what the market is doing. [HSha2] http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/eng4431
      • Modern hydro turbines can convert as much as 90% of the available energy into electricity. The best fossil fuel plants are only about 50% efficient.
      • In the US , hydropower is produced for an average of 0.7 cents per kilowatt-hour (kWh). This is about one-third the cost of using fossil fuel or nuclear and one-sixth the cost of using natural gas," as long as the costs for removing the dam and the silt it traps are not included.
      • Efficiency could be further increased by refurbishing hydroelectric equipment. An improvement of only 1% would supply electricity to an additional 300,000 households.

      • A hydropower plant has a high capital cost but maintenance costs are only minimal when looking at some other sources of energy production. The plant life can be extended economically by relatively cheap maintenance and the periodic replacement of equipment. [KCyw2]
      • Comparing the cost of electricity with the initial investment of a hydropower system, the pay back period is short. Theoretically, a hydro plant should be able to produce electricity for a fixed amount during the life span of the unit. The operating costs should not change because there is no associated price to the water. Unlike in fossil fuel plants, the price of natural gas, coal, etc. fluctuates depending on what the market is doing. [KCyw2]

www.britannica.com/EBchecked/topic/609552/turbine/45675/cost-of-hydroelectric-power)
[SHer8]

Although there are many suitable sites around the world, hydro-electric dams are
very
expensive to build. For example, the Hoover Dam cost $49,000,000. However, once the station is built, the water comes free of charge, and there is no waste or pollution.
http://www.darvill.clara.net/altenerg/hydro.htm#adv
[MMad7] A few recent studies of large reservoirs created behind hydro dams have suggested that decaying vegetation, submerged by flooding, may give off quantities of greenhouse gases equivalent to those from other sources of electricity. If this turns out to be true, hydroelectric facilities such as the James Bay project in Quebec that flood large areas of land might be significant contributors to global warming. Run of the river hydro plants without dams and reservoirs would not be a source of these greenhouse gases.

http://www.groept.be/www/dam/HYDROpower.htm#H4
[KCri7] The most obvious impact of hydroelectric dams is the flooding of vast areas of land, much of it previously forested or used for agriculture. The size of reservoirs created can be extremely large. The La Grande project in the James Bay region of Quebec has already submerged over 10000 square kilometres of land; and if future plans are carried out, the eventual area of flooding in northern Quebec will be larger than the country of Switzerland.

http://www.groept.be/www/dam/HYDROpower.htm#H4
[KCri7] Reservoirs can be used for ensuring adequate water supplies, providing irrigation, and recreation; but in several cases they have flooded the homelands of native peoples, whose way of life has then been destroyed. Many rare ecosystems are also threatened by hydroelectric development.

http://www.groept.be/www/dam/HYDROpower.htm#H4
[KCri7] Large dams and reservoirs can have other impacts on a watershed. Damming a river can alter the amount and quality of water in the river downstream of the dam, as well as preventing fish from migrating upstream to spawn.

http://www.groept.be/www/dam/HYDROpower.htm#H4
[KCri7] These impacts can be reduced by requiring minimum flows downstream of a dam, and by creating fish ladders, which allow fish to move upstream past the dam. Silt, normally carried downstream to the lower reaches of a river, is trapped by a dam and deposited on the bed of the reservoir. This silt can slowly fill up a reservoir, decreasing the amount of water, which can be stored and used for electrical generation. The river downstream of the dam is also deprived of silt, which fertilizes the river's flood plain during high water periods.

http://www.groept.be/www/dam/HYDROpower.htm#H4
[KCri7] Bacteria present in decaying vegetation can also change mercury, present in rocks underlying a reservoir, into a form, which is soluble in water. The mercury accumulates in the bodies of fish and poses a health hazard to those who depend on these fish for food.

http://www.groept.be/www/dam/HYDROpower.htm#H4
[KCri7] The water quality of many reservoirs also poses a health hazard due to new forms of bacteria, which grow in many of the hydro rivers. Therefore, run of the river type hydro plants generally have a smaller impact on the environment.

http://www.groept.be/www/dam/HYDROpower.htm#H4
[KCri7] (These are actually environmental impacts of hydroelectric power but I accidentally entered them into economic. My computer would not let me copy them into the environmental impacts so I'm really sorry.)

Small scale hydro power or micro-hydro power is increasingly used as an alternative energy source. It is becoming popular in remote areas where other power sources are not available. Small scale hydro power systems can be installed on small streams or rivers without the use of a dam which makes the system environmentally friendly, and legal issues with water rights would be reduced. The U.S. government supports the use of small scale hydro systems with grants, tax benefits, and loans.[MRec7]

Micro-hydro systems are simple to install, plus pipes and generators are inexpensive and easy to find. They are small enough to be installed without heavy equipment. The system requires only a small amount of water flow that can be provided by a small stream. Landowners with small streams can take advantage of this clean inexpensive alternative fuel source reducing their dependency on local utilities. [MRec7]

http://www.beyondfossilfuel.com/hydroelectric/

The gross revenue for the industry in 2000 was about $18 billion based on U.S. electricity production of 269 billion kilowatt hours and DOE's $0.066/kilowatt hour estimate for the national average value of electricity.[MRec7]

Using DOE's data, net profit for the industry in 2000 was calculated to be about $11 billion[MRec7]

after deducting licensing and regulatory costs (about $500 million), capital costs (about $4.6 billion), operation and maintenance costs (about $1.9 billion) [MRec7]

Few businesses that are 125 years old are as efficient and as important to the U.S. economy as the hydroelectric industry. [MRec7]
http://www.encyclopedia.com/doc/1G2-3401801974.html

Although large hydroelectric plants can be operated economically, the cost of land acquisition and of dam and reservoir construction must be included in the total cost of power, since these outlays generally account for about half of the total initial cost.
http://www.britannica.com/EBchecked/topic/609552/turbine/45675/Cost-of-hydroelectric-power [Asar8]

The 180MW Karkamis dam and hydroelectric plant cost $175 million and is one of the smaller dams in the South Eastern Anatolian Project (GAP). Dwarfed by the upstream Ataturk dam, it is 4.5km from the Turkish / Syrian border and 33km downstream from the now completed Birecik dam.
http://www.power-technology.com/projects/karkamis/ [Asar8]

Environmental impact of using hydroelectric power (Both +/-):

**





//.mapledesign.co.uk/writings/physics/2005_Hydroelectric_Power_Feasible_or_Desirable.pdf//[TCal8]
      • New locations for hydro sites are more difficult to develop because of environmental concerns. http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/eng4431 [HSha2]
      • Declining fossil-fuel prices and reductions in renewable energy tax credits are only partly responsible for the slowdown in hydropower development. Just as significant have been public opposition to new development and environmental regulations. [KCyw2]
      • Environmental regulations affect existing projects as well as new ones. For example, a series of large facilities on the Columbia River in Washington will probably be forced to reduce their peak output by 1,000 MW to save an endangered species of salmon. Salmon numbers have declined rapidly because the young are forced to make a long and arduous trip downstream through several power plants, risking death from turbine blades at each stage. [KCyw2]
      • The impact of very large dams is so great that there is almost no chance that any more will be built in the United States, although large projects continue to be pursued in Canada (the largest at James Bay in Quebec) and in many developing countries. The dams can cause radical changes in river ecosystems both upstream and downstream.[KCyw2]
      • Small hydropower plants using reservoirs can cause similar types of damage, though obviously on a smaller scale. [KCyw2]
      • Although existing hydro facilities can be upgraded with more efficient turbines, other plants can be refurbished, and some new small plants can be added, the total capacity and annual generation from hydro will probably not increase by more than 10 to 20 percent and may decline over the long term because of increased demand on water resources for agriculture and drinking water, declining rainfall (perhaps caused by global warming), and efforts to protect or restore endangered fish and wildlife. [KCyw2]
http://www.ucsusa.org/clean_energy/technology_and_impacts/impacts/environmental-impacts-of.html
it is clean, green, and renewable. hydro power does not contribute to local air pollution. [SHer8]
other energy generators are an important source of air and water and soil pollution along with greenhouse gases, they provide fewer oppertunities for economic spin-offs.-positive.[SHer8]
hydro developments are subject to extremely demandng environmental standards. before a project can be developed, it must go through a rigorus process that examines the impact of projects would have on the enviorment and on local communities. [SHer8]
consideration needs to be taken on water flows, quality shed, managment fish passage habitat protection and welfare and lifestyle of local communities.[SHer8]
(http://www1.agric.gov.ab.ca/$departmnt/deptdocs.nsf/all.eng443)
[SHer8]


The construction of the James Bay hydroelectric power project in subarctic Canada started in 1972, but environmental information that would permit mitigation measures did not become available until about 1975. It is suggested that this pattern may be characteristic of large-scale development projects in remote areas where the time lags involved in obtaining environmental data, beyond the simply descriptive information, are such that engineering plans would proceed, for economic reasons, without such environmental data as a planning input.
http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=6539556
[KCri7] Some environmental and social impact case studies are presented in this paper with regard to the LaGrande Complex phase of the James Bay development. The environmental impact case study involves the subsystem of estuarine fisheries and the effect on it of changes in the flow regime of the LaGrande River, the relocation of the first dam (LG-1) on the LaGrande, saltwater encroachment up the river during the filling of the second dam (LG-2), and the changes in the thermal regime of the river.

http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=6539556
[KCri7] China has embarked on a programme to vastly expand its hydroelectric generating capacity and this is certain to alter its freshwater and anadromous fish communities. To provide some insight into the direction and consequences of the likely changes, four (>250 000 kW) existing facilities were selected for review. The Gezhouba Dam, on the Changjiang River, commissioned in 1981, is a low-head run of the river facility. The Xinanjiang Dam (1959) is a high-head dam and the Fuchunjiang Dam (1968) is a low-head, run of the river dam, both sited on the Quiantang River. The Danjiangkou Dam (1968) is a high-head dam in the Han River, a tributary of the Changjiang River. Impacts on fish were classified as those caused directly by the structures, those resulting from changes in physical and chemical factors in their environment and those induced through biotic changes in their habitat.

http://www3.interscience.wiley.com/journal/21283/abstract?CRETRY=1&SRETRY=0
[KCri7] Migrations of anadromous and semi-migratory fish were blocked by the Gezhouba Dam, although some species adapted to the new environment by reproducing downstream. Below the Xinanjiang and Danjiangkou dams spawning was delayed 20-60 days by lower water temperatures. Reduced water velocities and less variable discharges caused spawning grounds below the dams to be abandoned.

http://www3.interscience.wiley.com/journal/21283/abstract?CRETRY=1&SRETRY=0
[KCri7] Marked changes in the hydrological regime caused the extinction of

Macrura reevesii,
a highly valued fish, in the Qiantang River. The fish communities in the Qiantang estuary were affected by the regulated discharge. Freshwater species fell from 96 to 85, whereas marine species increased from 15 to 80.
http://www3.interscience.wiley.com/journal/21283/abstract?CRETRY=1&SRETRY=0
[KCri7] Loss of habitat eliminated torrential habitat species from the areas inundated by Xinanjiang and Danjiangkou Reservoirs; lentic fish replaced lotic species and now dominate the reservoir fish communities. The expanded aquatic habitat was beneficial for fishery production. Catches from the two reservoirs continue to increase 20 years after impoundment, but are supported by extensive artificial propagation and stocking. There is no doubt that, when the expansion of China's hydroelectric facility network is complete, the fish communities in its rivers will be markedly changed.

http://www3.interscience.wiley.com/journal/21283/abstract?CRETRY=1&SRETRY=0
[KCri7] One incentive for hydroelectric facilities to help mitigate their overall impact on the environment is through green power certification. The Low Impact Hydropower Institute (LIHI) created a voluntary certification program whereby facilities are classified as low impact after passing a series of tests that demonstrate minimal impact.

http://www.enviroliteracy.org/article.php/59.html
[KCri] In 2007, less than 30 facilities in the U.S. had that distinction. Certification programs, such as the one set by the LIHI, can benefit hydropower efforts by attracting consumers concerned about energy source impacts.

http://www.enviroliteracy.org/article.php/59.html
[KCri7] While the use of water to produce electricity is an attractive alternative to fossil fuels, the technology must still overcome obstacles related to space requirements, building costs, environmental impacts, and the displacement of people. However, within the U.S., possible locations for new hydropower projects are beginning to diminish.

http://www.enviroliteracy.org/article.php/59.html
[KCri7]



carshttp://www.altenergy.org/renewables/hydroelectric.html
http://www.altenergy.org/renewables/hydroelectric.html
http://www.altenergy.org/renewables/hydroelectric.html
http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=6539556
http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=6539556
http://www3.interscience.wiley.com/journal/21283/abstract?CRETRY=1&SRETRY=0
http://www3.interscience.wiley.com/journal/21283/abstract?CRETRY=1&SRETRY=0
Macrura reevesii,http://www3.interscience.wiley.com/journal/21283/abstract?CRETRY=1&SRETRY=0
http://www3.interscience.wiley.com/journal/21283/abstract?CRETRY=1&SRETRY=0
http://www.enviroliteracy.org/article.php/59.html
http://www.enviroliteracy.org/article.php/59.html
http://www.enviroliteracy.org/article.php/59.html

· In some mountainous countries, such as Canada, Norway, Sweden, and Switzerland, hydroelectric power provides a high percentage of the national electricity supply. These nations rely heavily on hydroelectric power because they have many large urban and industrial areas in, or relatively close to, mountainous areas.
http://www.marshallcavendishdigital.com/articledisplayresult/6/3544/35726 [Asar8]

The hydroelectric power potential of the world is very large. Some rivers are particularly notable for their potentials. The Yenisey-Angara in Russia is estimated at some 64,000 MW, and India’s Bramaputra at some 20,000 MW.

http://www.marshallcavendishdigital.com/articledisplayresult/6/3544/35726 [Asar8]

If completed, the Three Gorges Dam on the Yangtze will be the largest hydroelectric dam in the world. It will be 6,342 ft. (2,150 m) wide and 3,327 ft. (185 m) high, across the world’s third longest river. Its reservoir will be over 335 miles (600 km) long. Construction began in 1994 and is scheduled to take 20 years; the project is expected to cost over $24 billion.

http://www.marshallcavendishdigital.com/articledisplayresult/6/3544/35726 [Asar8]

The enormous cost of hydroelectric plants is just one factor. More crucial is the health of a country’s economy. Hydroelectric plants are suitable for an economy that has a high demand for electricity. Therefore, there must be enough people who can purchase electrical appliances to pay for the scheme. A poor country may simply have insufficient demand for electricity to enable hydropower to be an economical alternative to oil.

http://www.marshallcavendishdigital.com/articledisplayresult/6/3544/35726 [Asar8]

If all the rivers and streams in the world could be used for hydroelectricity, they would supply the world’s power needs comfortably. This is not possible for a number of reasons. In some areas, rivers flow across flat land that has no deep valleys in which to build dams. In others, rivers carry little water in the drier parts of the year. Some areas that would be good places to build plants are too remote, and it would cost too much to build and operate them there.

http://www.marshallcavendishdigital.com/articledisplayresult/32/6964/71008http://www.marshallcavendishdigital.com/articledisplayresult/32/6964/71008 [Asar8]

Is there be any opposition to the use of hydroelectric power? Why? Do you agree or disagree with those views?:

      • I don't there is really any opposition to Hydroelectric power, at least it hasnt gone public. I searched online and could find no negative opinions on the usage of hydroelectric power plants. [TCal8]
      • Many people think hydroelectric power has had a huge impact on our nations electic power industry.
//http://www.usbr.gov/power/edu/pamphlet.pdf//[TCal8]
      • One positive detail; it creates no pollution. One negative detail; sometimes large areas are drowned by building the dam and people are displaced. This is one of the only negative thoughts I have found. [KCyw2]
http://wiki.answers.com/Q/What_are_positive_and_negative_effects_on_the_enviorment_from_hydroelectric_energy
there are oppositions to hydroelectric power. dam's can detract from natural setting, ruin nature's work.[SHer8]
they have inudated the spawning grounds of fish inhabited ,migration of fish.[SHer8]
threated endagered species of fish. they can even cause earthqwakes.[SHer8]
(http://www.simscience,org/crack/advanced/dams4.html)
[SHer8]

There is a debate between preserving rivers for their aesthetic value versus meeting the energy needs of thousands of people. The latter has prevailed. Today "there are 600,000 river miles impounded behind dams. In contrast, only 10,000 river miles (not even half of 1%) are permanently protected under the National Wild and Scenic Rivers System." The only undammed river in the US that is longer than 600 miles is the Yellowstone. http://www.altenergy.org/renewables/hydroelectric.html [MMad7]
This debate poses two worthy standpoints; either the preservation of more natural rivers, or the potential usage of energy for many people from these rivers. I agree with the viewpoint that it is better to grasp the opportunity of building dams in rivers instead of preserving them naturally because the enormous amount of energy that could potentially be harnessed would even further spread the many advantages of hydropower. Although the preservation is very important, for example as in the Yellowstone River, I believe that as long as certain rivers stay protected there will still be plenty of natural rivers. [MMad7]
Traditionally thought of as a cheap and clean source of electricity, most large hydro-electric schemes being planned today are coming up against a great deal of opposition from environmental groups and native people. http://www.greenenergycouncil.com/hydro_elec.htm [KCri7]


Hydroelectricity is a clean and renewable energy source, but it has some drawbacks. It takes around ten years to plan and build a hydro plant. Constructing dams is usually very expensive. Damming rivers can also damage the environment. The lake behind a dam can cover important wildlife habitats, archeological sites, farmland, and even entire towns and villages.
http://www.marshallcavendishdigital.com/articledisplayresult/32/6964/71008 [Asar8]

Would there be any societal impacts to the use of hydroelectric power?

          • Hydroelectric power is usually only made by national projects, because the general society is not really in favor of smaller projects because the people don't have easy access to such large volumes of water. [AAgu8]
//http://ezinearticles.com/?Hydroelectric-Energy-How-Energy-is-Obtained-From-Moving-Water&id=2601675//
reservoirhttp://ga.water.usgs.gov/edu/wuhy.html
      • Hydroelectric power for the most part is pollution-free, but there are environmental and social impacts involved. The operation of hydropower stations, which includes the construction of dams, can represent a significant disturbance to the natural environment and local communities.[KCyw2]
      • One low-impact option is to improve existing hydropower stations and make them more efficient. When constructing new hydropower projects, WWF advocates social and environmental safeguards, which are based on the guidelines of the World Commission on Dams. This includes comprehensive planning to determine energy needs and a thorough options assessment, which evaluates all alternatives.[KCyw2]
http://www.panda.org/what_we_do/footprint/climate_carbon_energy/energy_solutions/renewable_energy/clean_energy_facts/hydro_energy_facts/

The most often heard claims in support of large scale hydroelectric development are: (1) hydropower generation is ‘clean’, (2) water flowing freely to the ocean is ‘wasted’, and (3) local residents (usually aboriginals) will benefit from the development.
http://www.sciencedirect.com/science?_ob=ArticleURL
[KCri7] The social impact case study examines the effect of the road network associated with the hydro development, on the land tenure system of the native Cree Indians of the area.

http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=6539556
[KCri7] The behavior of developers, as they optimize their engineering plans over the years to develop as much power as is feasible, is contrasted with the behavior of the organizations representing the native peopleof the area, first opposing the project but later giving up the aboriginal title to the land in exchange for some legally recognized rights, and subsequently making additional concessions from their established rights in exchange for various community benefits. It is argued that this process has been resulting in an incremental erosion of the land and resource base of the Cree Indian people.

http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=6539556
[KCri7]


http://cie.ge/data/file_db/reports%20and%20other%20information/ESIA_report_ARpplpkn_o.pdf
http://www.sciencedirect.com/science?_ob=ArticleURL
http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=6539556
http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=6539556

hydroelectricity is important to the nation about seven % of total power is produced by its plants. (http://ga.water.usgs.gov/edu/WUhy.html) [SHer8]

The damming of streams and rivers has been an integral part of human civilization from its early history. Controversy paralleled this use because impounding and diverting water for upstream users affects those who live downstream, and also modifies the local habitats of plants and animals. [MRec7]
http://www.waterencyclopedia.com/Ge-Hy/Hydroelectric-Power.html

Since 1986, at least half the costs of dam construction was required to come from local governments, and many large projects were therefore cut back or eliminated. Meanwhile, the Public Utility Regulatory Policies Act of 1978 brought in provisions that require utilities to buy excess power generated by small private systems at a fair price. In turn, this paved the way for small communities and even individual homeowners to operate their own mini- hydroelectric plants, using low-head dams or smaller existing dams that had been shut down because of high cost at an earlier time. Thus, the political and financial picture of hydroelectric power plants is continually changing.
http://www.marshallcavendishdigital.com/articledisplayresult/25/3802/38678 [Asar8]

A good example of a project that has raised much public concern is the construction of the Three Gorges Dam on the Chang River in China. By blocking the flow of the Chang River, the dam will create a 370-mile- (595-km-) long reservoir west of the city of Yichang. When it is completed, the dam will provide around the same amount of energy as 15 large coal-burning power plants. Proponents believe that the Three Gorges Dam will control flooding and provide a pollution-free source of electricity. However, many scientists believe that the construction of the dam will be an ecological disaster, destroying much of the surrounding environment. It is estimated that two million Chinese will be forced from their homes as a result of the construction.
http://www.marshallcavendishdigital.com/articledisplayresult/25/3802/38678 [Asar8]

How is it made?:

http://ga.water.usgs.gov/edu/wuhy.html
          • Hydroeldctricity is made from dams or called factories where they harness the power of the current in water to turn into electrons inside the dam at the generators. [AAgu8]
          • They intake water usually diverted around a natural drop of a river or they will build a dam at a river to raise one side of the river to create the effective drop in water needed. [AAgu8]
          • Water is collected at the forbays of the dam where water will flow into a pipe called a penstock. The penstock leads the water towards the lower level where the water wheel turbine is located. [AAgu8]
          • With the increased pressure and flow of the water, the tubine will start to turn creating the source of energy for the electrons. [AAgu8]
          • Large electro magnets called staters, which are usually wrapped in copper coiling. As the turbine spins from the water a flow of electrons is created within the copper coiling of the stater. [AAgu8]
          • The elctricity is then sent to transformers where they are increased in electrical energy and then sent to the transmission lines where the electricity will flow to areas providing power. [AAgu8]
          • The remaining water that is still left over will flow out of the pipe to rejoin the rest of the water where it will continue its journey downstream so it could repeat the cycle of hydroelectiricity. [AAgu8]
//http://home.clara.net/darvill/altenerg/hydro.htm//
      • Huge power generators are placed inside dams. Water flowing through the dams spin turbine blades (made out of metal instead of leaves) which are connected to generators. Power is produced and sent to homes and businesses. [KCyw2]
http://ga.water.usgs.gov/edu/wuhy.html
      • The amount of electric powerP that can be generated is given by the equation below, where Q is the volume
external image loadBinary.aspx?aID=5548&filename=216600MF0010.gif
Eugene C. Starr, Maris T. Fravel, Natarajan Sekhar, Dwight L. Glasscock, Thomas W. Reddoch, "Electric power generation", in AccessScience@McGraw-Hill, http://www.accessscience.com, DOI 10.1036/1097-8542.216600 [TCal8]
kineticmechanicalelectricityhttp://www.usbr.gov/power/edu/pamphlet.pdf
http://www.usbr.gov/power/edu/pamphlet.pdf
__http://ga.water.gov/edu/wuhy/html__

Hydroelectricity is electricity that is made by the movement of water. It is usually made with dam that block a river or collect water that is pumped there. When the water is "let go" the huge pressure behind the dam forces the water down shafts that lead to a turbine, this causes the turbine to turn, and electricity is produced. __http://ga.water.gov/edu/wuhy/html__
[RGov7]

hydro power stems form the process of using waters energy as it flows from higher to lower elevation, rotating hydraulic turbines to create electricity. (http://www.enviroliteracy.org/article.php/59.html) [SHer8]

1. The first hydroelectric power station in history started producing electricity in 1882, according to the Library of Congress web site. It was located in the state of Wisconsin, and used the Fox River for electrical generation.[DArn2]
2. Hydroelectric energy is used in many countries around the world, including Brazil, Canada, Russia, Tanzania, Iceland, North Korea, and New Zealand. It appears to be a popular option in almost every region, regardless of political or economic differences.[DArn2]
3. The state of California uses a large amount of hydroelectric energy. The California Energy Commission web site indicates that power stations of this type generated just over fifteen percent of California's electricity during 1999.[DArn2]
4. According to the U.S. Geological Survey web site, hydro power plants generate electricity by turning a turbine. Many electricity generation methods use turbines in one way or another, including wind, coal, and hand-operated dynamos.[DArn2]
5. China generates more hydroelectricity than any other country, as indicated by the China Daily. It also states that about twenty percent of electricity worldwide is generated with hydroelectric. China has built power stations of this kind in other countries as well.[DArn2]
6. Hydroelectric power plants are capable of functioning properly for a very long period of time. According to Natural Resources Canada, a large number of Canadian power stations of this type have been in use for over fifty years.[DArn2]
7. Hydropower is used to produce more electricity than other renewable methods of electricity generation in the U.S., according to the Energy Information Administration. This means that its use is more widespread than that of wind or solar power.[DArn2]
8. World-wide, about 20% of all electricity is generated by hydropower.[DArn2]
9. Hydropower provides about 10% of the electricity in the United States.[DArn2]
10. Hydroelectric power is one of the most widely used and cheapest ways to generate electricity today. Although there are a number of environmental issues associated with this form of renewable energy, there are ways to reduce the impacts.[DArn2]

11. hydroelectricity electricity generated from the motion of water. In all installations, this energy of movement, or kinetic energy, is first converted into mechanical energy in the spinning blades of a water turbine, and then into electricity by the spinning rotor of a generator. Many power stations are driven by water held back by large dams to regulate flow. Hydroelectric power (HEP) provides cheap energy for mountainous areas with high rainfall.[DArn2]
12. Even compared to other forms of renewable energy production, hydroelectric power is considered an excellent way to generate power because of its dependable output and low maintenance needs.[DArn2]
13. The reservoirs that dams form can also be beneficial in their own right. In dryer countries in the Middle East for example, the reservoirs of dams can become important ecosystems and can be used for farm irrigation as well as aquaculture activities.[DArn2]
14. Mechanical Energy Is Harnessed from Moving Water. The amount of available energy in moving water is determined by its flow or fall. [DArn2]
15. Hydropower is one of the oldest sources of energy. It was used thousands of years ago to turn a paddle wheel for purposes such as grinding grain.[DArn2]
16. Only a small percentage of all dams in the United States produce electricity. Most dams were constructed solely to provide irrigation and flood control.[DArn2]
17. In the United States, a study is required before constructing a hydroelectric project. [DArn2]
18. Due to the fact that plant-life decays in the flooded areas at an alarming rate, producing methane, as well as smaller amounts of carbon dioxide. Placement is key when it comes to constructing a hydroelectric dam.[DArn2]
19. Hydroelectricity is most commonly produced with the use of dams, however. Especially in areas where there are large flowing rivers and lakes to draw water from. For this reason, places like British Columbia, Canada, with large, intricate waterway systems take full advantage of this type of power.[DArn2]
20. Our nation’s first industrial use of hydropower to generate electricity occurred in 1880 [DArn2]
http://ga.water.usgs.gov/edu/hyhowworks.html [DArn2]
http://hubpages.com/hub/facts-about-hydroelectric-energy [DArn2]
http://www.encyclopedia.com/topic/hydroelectric_power.aspx [DArn2]



The micro-hydro turbine system is the most environmentally friendly system to make electricity. The turbine can be as small as 10 centimeters in diameter and consists of spoon shaped cups arranged around the center wheel. Jets of high pressure water causes the wheel to spin a shaft at high speeds which can be used to power electrical generators, pumps, fans, and more. The high pressure water required for a micro-hydro system can be supplied by water that flows down into a pipe above the micro-hydro turbine. The lower pipe then directs the water to nozzles aimed at the micro-turbine. The greater the distance from where the water enters and exits the pipe the greater the water pressure coming from the lower pipe will be.[MRec7]
http://www.beyondfossilfuel.com/hydroelectric/

"A hydraulic turbine converts the energy of flowing water into mechanical energy. A hydroelectric generator converts this mechanical energy into electricity.[MRec7]
In a large generator, electromagnets are made by circulating direct current through loops of wire wound around stacks of magnetic steel laminations. These are called field poles, and are mounted on the perimeter of the rotor. The rotor is attached to the turbine shaft, and rotates at a fixed speed. When the rotor turns, it causes the field poles (the electromagnets) to move past the conductors mounted in the stator. This, in turn, causes electricity to flow and a voltage to develop at the generator output terminals."[MRec7]

external image Storage.asp?StorageID=1609&SiteLanguageID=1[MRec7]

http://ga.water.usgs.gov/edu/hyhowworks.html
The simple workings of a hydropower plant has water flowing through a dam, which turns a turbine, which then turns a generator. A hydropower plant (including a powerhouse) generally includes the following steps:
1. The dam holds water back, and stores water upstream in a reservoir, or large artificial lake. The reservoir is often used for multiple purposes, such as the recreational Lake Roosevelt at the Grand Coulee Dam. Some hydroelectric dams do not impound water, but instead use the power of the flowing river, and are known as run-of-the-river.
2. Gates open on the dam, allowing gravity to pull the water down through the penstock. An intake conduit carries water from the reservoir to turbines inside the powerhouse. Pressure builds up as water flows through the pipeline.
3. The water then hits the large blades of the turbine, making them turn. The vertical blades are attached through a shaft to a generator located above. Each turbine can weigh as much as 172 tons and turn at a rate of 90 revolutions per minute.
4. The turbine blades turn in unison with a series of magnets inside the generator. The large magnets rotate past copper coils, which produce alternating current (AC).
5. The transformer inside the powerhouse takes the AC and converts it to higher-voltage current so as to allow electricity to flow to customers.
6. Out of every power plant exit four power lines consisting of three wires (associated with three power phases) and a neutral (ground) wire.
7. Used water is carried through outflow pipelines, which reenters the river downstream.
http://find.galegroup.com/gvrl/retrieve.do?contentSet=EBKS&resultListType=RESULT_LIST&qrySerId=Locale%28en%2C%2C%29%3AFQE%3D%28KE%2CNone%2C19%29hydroelectric+power%24&sgHitCountType=None&inPS=true&sort=Relevance&searchType=BasicSearchForm&tabID=T001&prodId=GVRL&searchId=R1&currentPosition=1&userGroupName=bhs&docId=CX3409400154&docType=EBKS&contentSet=EBKS [Asar8]


Although most energy in the United States is produced by fossil-fuel and nuclear power plants, hydroelectricity is still important to the Nation, as about 7 percent of total power is produced by hydroelectric plants. Nowadays, huge power generators are . Water flowing through the dams spin turbine blades (made out of metal instead of leaves) which are connected to generators. Power is produced and is sent to homes and businesses. http://ga.water.usgs.gov/edu/wuhy.html [HSha2] Hydropower is the most important and widely-used renewable source of energy. Hydropower represents 19% of total electricity production. China is the largest producer of hydroelectricity, followed by Canada, Brazil, and the United States (Source: Energy Information Administration). Approximately two-thirds of the economically feasible potential remains to be developed. Untapped hydro resources are still abundant in Latin America, Central Africa, India and China. http://ga.water.usgs.gov/edu/wuhy.html[HSha2] Advantages to hydroelectric power:
Fuel is not burned so there is minimal pollution
Water to run the power plant is provided free by nature
Hydropower plays a major role in reducing greenhouse gas emissions
Relatively low operations and maintenance costs
The technology is reliable and proven over time
It's renewable - rainfall renews the water in the reservoir, so the fuel is almost always there http://ga.water.usgs.gov/edu/wuhy.html[HSha2] Hydroelectric power is not perfect, though, and does have some disadvantages:
High investment costs
Hydrology dependent (precipitation)
In some cases, inundation of land and wildlife habitat
In some cases, loss or modification of fish habitat
Fish entrainment or passage restriction
In some cases, changes in reservoir and stream water quality
In some cases, displacement of local populations http://ga.water.usgs.gov/edu/wuhy.html[HSha2] In many countries, hydroelectric power provides nearly all of the electrical power. In 1998, the hydroelectric plants of Norway and the Democratic Republic of the Congo (formerly Zaire) provided 99 percent of each country's power; and hydroelectric plants in Brazil provided 91 percent of total used electricity. http://www.waterencyclopedia.com/Ge-Hy/Hydroelectric-Power.html[HSha2]
In the United States, more than 2,000 hydropower plants make hydro-electric power the country's largest renewable energy source (at 49 percent). The United States increased its hydroelectric power generation from about 16 billion kilowatt-hours in 1920 to nearly 306 billion kilowatt-hours in 1999. It runs a close second to Canada in the total amount of hydroelectric power produced worldwide. However, only 8 percent of the total U.S. electrical power was generated by hydroelectric power plants in 1999. http://www.waterencyclopedia.com/Ge-Hy/Hydroelectric-Power.html[HSha2]
how it works
The dam holds water back, and stores water upstream in a reservoir , or large artificial lake. The reservoir is often used for multiple purposes, such as the recreational Lake Roosevelt at the Grand Coulee Dam. Some hydroelectric dams do not impound water, but instead use the power of the flowing river, and are known as run-of-the-river.Gates open on the dam, allowing gravity to pull the water down through the penstock. An intake conduit carries water from the reservoir to turbines inside the powerhouse. Pressure builds up as water flows through the pipeline. The water then hits the large blades of the turbine , making them turn. The vertical blades are attached through a shaft to a generator located above. Each turbine can weigh as much as 172 tons and turn at a rate of 90 revolutions per minute. The turbine blades turn in unison with a series of magnets inside the generator. The large magnets rotate past copper coils, which produce alternating current (AC). The transformer inside the powerhouse takes the AC and converts it to higher-voltage current so as to allow electricity to flow to customers. Out of every power plant exit four power lines consisting of three wires (associated with three power phases) and a neutral (ground) wire. Used water is carried through outflowpipelines, which reenters the river downstream. http://www.waterencyclopedia.com/Ge-Hy/Hydroelectric-Power.html[HSha2]

Use of flowing water to create electricity is called hydroelectric energy. The most common type of hydroelectric plant uses a dam on a river to store water in a reservoir. Water released from the reservoir flows through a pipe and into a turbine, which spins to drive a generator, producing electricity.
Pumped storage plants use a two-reservoir system, pumping water from a river or a reservoir to a higher reservoir when electricity prices are low during the night. When the value of electricity on the grid is higher during the day, water is released from the upper reservoir, spinning the turbines to produce electricity.
http://www.williams.edu/Geoscience/greenenergy/hydroelectric.htm[HSha2]

A dam is built to trap water, usually in a valley where there is an existing lake.

Water is allowed to flow through tunnels in the dam, to turn and thus drive generators.
Notice that the dam is much thicker at the bottom than at the top, because the pressure of the water increases with depth.
Hydro-electric power stations can produce a great deal of power very cheaply. http://www.darvill.clara.net/altenerg/hydro.htm[HSha2]


When it was first built, the huge "Hoover Dam", on the Colorado river, supplied much of the electricity for the city of Las Vegas; however now Las Vegas has grown so much, the city gets most of its energy from other sources. http://www.darvill.clara.net/altenerg/hydro.htm[HSha2] Advantages


  • Once the dam is built, the energy is virtually free.
  • No waste or pollution produced.
  • Much more reliable than wind, solar or wave power.
  • Water can be stored above the dam ready to cope with peaks in demand.
  • Hydro-electric power stations can increase to full power very quickly, unlike other power stations.
  • Electricity can be generated constantly http://www.darvill.clara.net/altenerg/hydro.htm[HSha2]

Disadvantages

  • The dams are very expensive to build.
    However, many dams are also used for flood control or irrigation, so building costs can be shared.
  • Building a large dam will flood a very large area upstream, causing problems for animals that used to live there.
  • Finding a suitable site can be difficult - the impact on residents and the environment may be unacceptable.
  • Water quality and quantity downstream can be affected, which can have an impact on plant life. http://www.darvill.clara.net/altenerg/hydro.htm[HSha2]

Hydro-electric power is .
The Sun provides the water by evaporation from the sea, and will keep on doing so.
http://www.darvill.clara.net/altenerg/hydro.htm[HSha2]
History of Hydroelectric Power

- Nearly 2000 years ago the Greeks used water wheels to grind wheat into flour
- In the 1700's, hydropower was broadly used for milling of lumber and grain and for pumping irrigation water
- Appleton, Wisconsin became the first operational hydroelectric generating station in the United States, in 1882, producing 12.5 kilowatts (kW) of power
- The total electrical capacity generated was equivalent to 250 lights
- Within the next 20 years roughly 300 hydroelectric plants were operational around the world
- The invention of the hydraulic reaction turbine created the sudden expansion of hydropower
- 40% of the United States' electricity was provided by hydroelectric power in the early 1900'swer, Hydropower Dam in Little Falls, MN
- The largest and last masonry dam built by the U.S. Bureau of Reclamation was the Roosevelt Dam in Arizona between 1905-1911; its power output has increased from 4,500 kW to 36,000 kW
- In 1933, the Tennessee Valley Authority Act was enacted into law
- The Hoover Dam first generated power in 1937, producing 130,000 kW
- By the 1940's, hydroelectric power supplied roughly 75% of the electricity used in the western United States and approximately one-third of the United States' total electric energy
- Still in use today, Niagra Falls was the first hydropower site developed for a vast quantity of electricity
- Nearly 10% of the United States' electricity came from hydroelectric power in 1997
- In the United States hydropower generates over 90,000 megawatts (mW); this could supply about 28.3 million customers (estimated population in 2001 was 284.4 million people) which is still less than 10% of the populace. http://ffden-2.phys.uaf.edu/104_spring2004.web.dir/Todd_Robyn/Page5.htm[HSha2]


To generate hydroelectric power, water is collected or stored in a reservoir at a high elevation and is forced downward by pressure and gravity through large pipes to a lower elevation. As the water flows from the higher to the lower level, it rotates turbines. The turbines turn generators, which produce electricity
http://www.marshallcavendishdigital.com/articledisplayresult/6/3544/35726 [Asar8]
The difference between the two elevations is known as the head. The greater the head, the greater the potential energy of the water. So, to produce a given amount of power, the higher the head, the smaller the volume of water required. The amount of power that a hydroelectric power plant can produce is dictated by the head, the maximum volume of water that can flow past the turbines, and the condition of the reservoir.

http://www.marshallcavendishdigital.com/articledisplayresult/6/3544/35726 [Asar8]





Environmental damage



Hydroelectric projects can be disruptive to surrounding aquatic ecosystems both upstream and downstream of the plant site. For instance, studies have shown that dams along the Atlantic and Pacific coasts of North America have reduced salmon populations by preventing access to spawning grounds upstream, even though most dams in salmon habitat have fish ladders installed. Salmon spawn are also harmed on their migration to sea when they must pass through turbines. This has led to some areas transporting smolt downstream by barge during parts of the year. In some cases dams have been demolished (for example the Marmot Dam demolished in 2007)[15] because of impact on fish. Turbine and power-plant designs that are easier on aquatic life are an active area of research. Mitigation measures such as fish ladders may be required at new projects or as a condition of re-licensing of existing projects.
Generation of hydroelectric power changes the downstream river environment. Water exiting a turbine usually contains very little suspended sediment, which can lead to scouring of river beds and loss of riverbanks.[16] Since turbine gates are often opened intermittently, rapid or even daily fluctuations in river flow are observed. For example, in the Grand Canyon, the daily cyclic flow variation caused by Glen Canyon Dam was found to be contributing to erosion of sand bars. Dissolved oxygen content of the water may change from pre-construction conditions. Depending on the location, water exiting from turbines is typically much warmer than the pre-dam water, which can change aquatic faunal populations, including endangered species, and prevent natural freezing processes from occurring. Some hydroelectric projects also use canals to divert a river at a shallower gradient to increase the head of the scheme. In some cases, the entire river may be diverted leaving a dry riverbed. Examples include the Tekapo and Pukaki Rivers inNew Zealand. http://en.wikipedia.org/wiki/Hydroelectricity#Environmental_damage
[HSha2]
Hydroelectric power is one of the most widely used and cheapest ways to generate electricity today. Although there are a number of environmental issues associated with this form of renewable energy, there are ways to reduce the impacts.http://www.panda.org/what_we_do/footprint/climate_carbon_energy/energy_solutions/renewable_energy/clean_energy_facts/hydro_energy_facts/
[HSha2]
Hydroelectric power for the most part is pollution-free, but there are environmental and social impacts involved.http://www.panda.org/what_we_do/footprint/climate_carbon_energy/energy_solutions/renewable_energy/clean_energy_facts/hydro_energy_facts/
[HSha2]
The operation of hydropower stations, which includes the construction of dams, can represent a significant disturbance to the natural environment and local communities. http://www.panda.org/what_we_do/footprint/climate_carbon_energy/energy_solutions/renewable_energy/clean_energy_facts/hydro_energy_facts/[HSha2]

In developing countries, local populations tend to benefit less from hydropower as the generated electricity is often exported to urban regions or outside the country. http://www.panda.org/what_we_do/footprint/climate_carbon_energy/energy_solutions/renewable_energy/clean_energy_facts/hydro_energy_facts/
[HSha2]

replacing oil?
A large hydroelectric dam can generate roughly 18 gigawatts of power per year. Thus, to offset one CMO of energy, we’d have to build 200 major hydroelectric external image 2_bing.gif. The problem? There aren’t enough rivers left in the world to dam up. http://www.outsidethebeltway.com/archives/replacing_oil_aint_easy/ [HSha2]



Hadey sent me a listing of all of her sources again to post...here they are...

Although most energy in the United States is produced by fossil-fuel and nuclear power plants, hydroelectricity is still important to the Nation, as about 7 percent of total power is produced by hydroelectric plants. Nowadays, huge power generators are . Water flowing through the dams spin turbine blades (made out of metal instead of leaves) which are connected to generators. Power is produced and is sent to homes and businesses. http://ga.water.usgs.gov/edu/wuhy.html
Hydropower is the most important and widely-used renewable source of energy. Hydropower represents 19% of total electricity production. China is the largest producer of hydroelectricity, followed by Canada, Brazil, and the United States (Source: Energy Information Administration). Approximately two-thirds of the economically feasible potential remains to be developed. Untapped hydro resources are still abundant in Latin America, Central Africa, India and China. http://ga.water.usgs.gov/edu/wuhy.html
Advantages to hydroelectric power:
Fuel is not burned so there is minimal pollution
Water to run the power plant is provided free by nature
Hydropower plays a major role in reducing greenhouse gas emissions
Relatively low operations and maintenance costs
The technology is reliable and proven over time
It's renewable - rainfall renews the water in the reservoir, so the fuel is almost always there http://ga.water.usgs.gov/edu/wuhy.html Hydroelectric power is not perfect, though, and does have some disadvantages:
High investment costs
Hydrology dependent (precipitation)
In some cases, inundation of land and wildlife habitat
In some cases, loss or modification of fish habitat
Fish entrainment or passage restriction
In some cases, changes in reservoir and stream water quality
In some cases, displacement of local populations http://ga.water.usgs.gov/edu/wuhy.html In many countries, hydroelectric power provides nearly all of the electrical power. In 1998, the hydroelectric plants of Norway and the Democratic Republic of the Congo (formerly Zaire) provided 99 percent of each country's power; and hydroelectric plants in Brazil provided 91 percent of total used electricity. http://www.waterencyclopedia.com/Ge-Hy/Hydroelectric-Power.html
In the United States, more than 2,000 hydropower plants make hydro-electric power the country's largest renewable energy source (at 49 percent). The United States increased its hydroelectric power generation from about 16 billion kilowatt-hours in 1920 to nearly 306 billion kilowatt-hours in 1999. It runs a close second to Canada in the total amount of hydroelectric power produced worldwide. However, only 8 percent of the total U.S. electrical power was generated by hydroelectric power plants in 1999. http://www.waterencyclopedia.com/Ge-Hy/Hydroelectric-Power.html
how it works
The dam holds water back, and stores water upstream in a reservoir , or large artificial lake. The reservoir is often used for multiple purposes, such as the recreational Lake Roosevelt at the Grand Coulee Dam. Some hydroelectric dams do not impound water, but instead use the power of the flowing river, and are known as run-of-the-river.Gates open on the dam, allowing gravity to pull the water down through the penstock. An intake conduit carries water from the reservoir to turbines inside the powerhouse. Pressure builds up as water flows through the pipeline. The water then hits the large blades of the turbine , making them turn. The vertical blades are attached through a shaft to a generator located above. Each turbine can weigh as much as 172 tons and turn at a rate of 90 revolutions per minute. The turbine blades turn in unison with a series of magnets inside the generator. The large magnets rotate past copper coils, which produce alternating current (AC). The transformer inside the powerhouse takes the AC and converts it to higher-voltage current so as to allow electricity to flow to customers. Out of every power plant exit four power lines consisting of three wires (associated with three power phases) and a neutral (ground) wire. Used water is carried through outflow pipelines, which reenters the river downstream. http://www.waterencyclopedia.com/Ge-Hy/Hydroelectric-Power.html

Use of flowing water to create electricity is called hydroelectric energy. The most common type of hydroelectric plant uses a dam on a river to store water in a reservoir. Water released from the reservoir flows through a pipe and into a turbine, which spins to drive a generator, producing electricity.
Pumped storage plants use a two-reservoir system, pumping water from a river or a reservoir to a higher reservoir when electricity prices are low during the night. When the value of electricity on the grid is higher during the day, water is released from the upper reservoir, spinning the turbines to produce electricity.

http://www.williams.edu/Geoscience/greenenergy/hydroelectric.htm
A dam is built to trap water, usually in a valley where there is an existing lake.

Water is allowed to flow through tunnels in the dam, to turn and thus drive generators.
Notice that the dam is much thicker at the bottom than at the top, because the pressure of the water increases with depth.
Hydro-electric power stations can produce a great deal of power very cheaply. http://www.darvill.clara.net/altenerg/hydro.htm

When it was first built, the huge "Hoover Dam", on the Colorado river, supplied much of the electricity for the city of Las Vegas; however now Las Vegas has grown so much, the city gets most of its energy from other sources. http://www.darvill.clara.net/altenerg/hydro.htm Advantages

  • Once the dam is built, the energy is virtually free.
  • No waste or pollution produced.
  • Much more reliable than wind, solar or wave power.
  • Water can be stored above the dam ready to cope with peaks in demand.
  • Hydro-electric power stations can increase to full power very quickly, unlike other power stations.
  • Electricity can be generated constantly http://www.darvill.clara.net/altenerg/hydro.htm

Disadvantages
  • The dams are very expensive to build.
    However, many dams are also used for flood control or irrigation, so building costs can be shared.
  • Building a large dam will flood a very large area upstream, causing problems for animals that used to live there.
  • Finding a suitable site can be difficult - the impact on residents and the environment may be unacceptable.
  • Water quality and quantity downstream can be affected, which can have an impact on plant life. http://www.darvill.clara.net/altenerg/hydro.htm

Hydro-electric power is**.
The Sun provides the water by evaporation from the sea, and will keep on doing so.
http://www.darvill.clara.net/altenerg/hydro.htm
History of Hydroelectric Power

- Nearly 2000 years ago the Greeks used water wheels to grind wheat into flour
- In the 1700's, hydropower was broadly used for milling of lumber and grain and for pumping irrigation water
- Appleton, Wisconsin became the first operational hydroelectric generating station in the United States, in 1882, producing 12.5 kilowatts (kW) of power
- The total electrical capacity generated was equivalent to 250 lights
- Within the next 20 years roughly 300 hydroelectric plants were operational around the world
- The invention of the hydraulic reaction turbine created the sudden expansion of hydropower
- 40% of the United States' electricity was provided by hydroelectric power in the early 1900'swer, Hydropower Dam in Little Falls, MN
- The largest and last masonry dam built by the U.S. Bureau of Reclamation was the Roosevelt Damin Arizona between 1905-1911; its power output has increased from 4,500 kW to 36,000 kW
- In 1933, the Tennessee Valley Authority Actwas enacted into law
- The Hoover Damfirst generated power in 1937, producing 130,000 kW
- By the 1940's, hydroelectric power supplied roughly 75% of the electricity used in the western United States and approximately one-third of the United States' total electric energy
- Still in use today, Niagra Fallswas the first hydropower site developed for a vast quantity of electricity
- Nearly 10% of the United States' electricity came from hydroelectric power in 1997
- In the United States hydropower generates over 90,000 megawatts (mW); this could supply about 28.3 million customers (estimated population in 2001 was 284.4 million people) which is still less than 10% of the populace. http://ffden-2.phys.uaf.edu/104_spring2004.web.dir/Todd_Robyn/Page5.htm





Environmental damage



Hydroelectric projects can be disruptive to surrounding aquatic both upstream and downstream of the plant site. For instance, studies have shown that dams along the and coasts of have reduced populations by preventing access togrounds upstream, even though most dams in salmon habitat have installed. Salmon are also harmed on their migration to sea when they must pass through . This has led to some areas transporting smolt downstream by during parts of the year. In some cases dams have been demolished (for example the demolished in 2007)[15[[http://www.me.com/mail/#cite_note-14|]]]because of impact on fish. Turbine and power-plant designs that are easier on aquatic life are an active area of research. Mitigation measures such as fish ladders may be required at new projects or as a condition of re-licensing of existing projects.
Generation of hydroelectric power changes the downstream river environment. Water exiting a turbine usually contains very little suspended sediment, which can lead to scouring of river beds and loss of riverbanks.[16[[http://www.me.com/mail/#cite_note-15|]]]Since turbine gates are often opened intermittently, rapid or even daily fluctuations in river flow are observed. For example, in the , the daily cyclic flow variation caused by was found to be contributing to erosion of sand bars. Dissolved content of the water may change from pre-construction conditions. Depending on the location, water exiting from turbines is typically much warmer than the pre-dam water, which can change aquatic faunal populations, including , and prevent natural freezing processes from occurring. Some hydroelectric projects also use to divert a river at a shallower gradient to increase the head of the scheme. In some cases, the entire river may be diverted leaving a dry riverbed. Examples include the and in . http://en.wikipedia.org/wiki/Hydroelectricity#Environmental_damage
Hydroelectric power is one of the most widely used and cheapest ways to generate electricity today. Although there are a number of environmental issues associated with this form of renewable energy, there are ways to reduce the impacts.http://www.panda.org/what_we_do/footprint/climate_carbon_energy/energy_solutions/renewable_energy/clean_energy_facts/hydro_energy_facts/
Hydroelectric power for the most part is pollution-free, but there are environmental and social impacts involved.http://www.panda.org/what_we_do/footprint/climate_carbon_energy/energy_solutions/renewable_energy/clean_energy_facts/hydro_energy_facts/
The operation of hydropower stations, which includes the construction of dams, can represent a significant disturbance to the natural environment and local communities. http://www.panda.org/what_we_do/footprint/climate_carbon_energy/energy_solutions/renewable_energy/clean_energy_facts/hydro_energy_facts/

In developing countries, local populations tend to benefit less from hydropower as the generated electricity is often exported to urban regions or outside the country. http://www.panda.org/what_we_do/footprint/climate_carbon_energy/energy_solutions/renewable_energy/clean_energy_facts/hydro_energy_facts/


replacing oil?
A large hydroelectric dam can generate roughly 18 gigawatts of power per year. Thus, to offset one CMO of energy, we’d have to build 200 major . The problem? There aren’t enough rivers left in the world to dam up. http://www.outsidethebeltway.com/archives/replacing_oil_aint_easy/
Taylor McMurtry's info in no particular order....
History

1)Enterprising businessmen recognized the power inherent in falling water: the invention of the waterwheel to drive simple machinery soon became a favored method of milling grains.
2) The ability to use water to mill flour encouraged the development of the new world as adventurers struck out to look for promising lands with which to both grow crops and produce milled grain for market. __North America__'s abundant __rivers__ provided many, many spots where available falling water could be harnessed to move grindstones and sawmills. Where naturally falling water was not sufficient, small dams were constructed to build up sufficient force to power the mill.
3) In America water power was first harnessed in the northeast and soon used to power textile mills, sawmills and other simple machinery.
4) Most of the American continent was settled first by locating a small dam and mill to provide the production necessary to drive a local economy.
5) It wasn't until the development of the generator in the 1880's that water-generated electricity became a viable use for the mill.
6)The role of the generator and the new discovery of alternating current finally made hydro-electric power available to power street lights, __homes__ and factories.
7) Within twenty years, this proliferation of private dams began to impede river traffic and the federal government began looking for ways to control its proliferation. Congress undertook the regulation of dams in the Rivers and Harbors Acts of 1890 and 1899. The Secretary of War and the Army Corps of Engineers was assigned responsibility for issuing permits and assuring that navigation remained open, even to the extent of taking control of the private dams when needed to improve navigation.
8) By 1906, The General Dam Act transferred title to many dams to the __federal government__
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. Government was concerned not simply with navigation however, but with development of a comprehensive plan to facilitate navigation, industrial development and flood control. The goal ultimately became for hydroelectric power generation to pay for the costs of developing navigation and for the transmission of electricity. Within a very few years, government became the deciding factor in where dams would be placed and how they would be built and used.
9) Dams and hydropower generation remained in private hands under the regulation of government until World War I, with the Corps __installing__ power stations, providing permits and generally have much control over operations. Investigating agency reports were already saying that government ownership of the dams would create enough return from electricity generation to pay for both improvements and the amortization of capitol spent in their building within 50 years.
10) When World War I ended Congress created the Federal Power __Commission__ (FPC) as the licensing agency for all nonfederal hydropower activity affecting or potentially affecting navigable waterways. By 1931, the Corps had completed 276 engineering reports, held 69 hearings, and was overseeing 129 licensees.
11) Under the federal Power Act, the Corps built dams in partnership with private companies. The licenses allowed the private corporations to develop the power facilities at what were essentially considered navigational dams. The private partners were allowed to sell the power produced and pay leasing fees to the government.
12) Federal hydropower development emphasis changed under the New Deal. Previously, the sale of surplus power was used to provide __funds__ for other projects, Under Roosevelt, a way was seen to provide cheap power to a wider market.
13) During the Eisenhower administration it was obvious that the federal government could no longer afford to develop the majority of the hydroelectric power needed by the growing economy. But federal development of hydroelectric power continued nearly unabated for the next twenty years.
14) By 1970 federal interest, both via the Corps'-controlled generation and the TVA-generated hydro-electric power constituted nearly half of all hydroelectric power generated in the __United States__.
http://www.helium.com/items/1151635-what-happened-to-hydroelectric-power

15) Very high capital cost or investment: The initial cost of the __construction__ of the hydroelectric power plants is very high. __http://www.brighthub.com/engineering/mechanical/articles/7730.aspx#ixzz0c3qWRPTD__(TMCM2)

16) Site specific: The hydroelectric power plants cannot be constructed at any locations. They can be constructed only in places where abundant quantity of water is available at sufficient height and throughout the year. A number of other safety parameters also have to be considered. __http://www.brighthub.com/engineering/mechanical/articles/7730.aspx#ixzz0c3qcSCRo__(TMCM2)

17) Affects on environment: Though the hydroelectric power plants do not require any fuel, don’t produce __greenhouse gases__ and don’t create pollution directly, it does have a number of detrimental affects on the environment. The construction activity of the dam itself disturbs the environment to a great scale.
__http://www.brighthub.com/engineering/mechanical/articles/7730.aspx#ixzz0c3qhlDcX__(TMCM2)


18) Disrupts the aquatic ecosystems: The dams developed across the rivers can disturb the aquatic life and lead to their large scale destruction. There are chances that the fishes and other water animals may enter the penstock and ultimately the power generation turbines where they may get crashed. The dams can also disturb the mating seasons and mating areas of the water animals.
http://www.brighthub.com/engineering/mechanical/articles/7730.aspx#ixzz0c3qhlDcX(TMCM2)

19) Large scale human displacement: For the construction of the dams even the human beings living in the areas surrounding the river have to be shifted. Human beings tend to have strong attachments to the lands occupied by them and their ancestors since hundreds of years. It is not easy to convince the people to leave the lands. People are convinced or forced to leave the land which not only is their shelter but also the source of income. In many instances, when people are snatched away of their lands, they are not given proper remuneration and the other land for resettlement. This creates large scale oppositions and revolts against construction of the dams.
http://www.brighthub.com/engineering/mechanical/articles/7729.aspx#ixzz0c3r5b6QI(TMCM2)

20) Requires large areas: The construction of dam, the power generation unit and the transformers and their connection to the national grid acquires large areas of the forest. The larger the land acquired for the dam, more is the disturbance to the natural ecosystem in the surrounding forest areas.
http://www.brighthub.com/engineering/mechanical/articles/7729.aspx#ixzz0c3rA7XSl(TMCM2)