Hydroelectric dam in cross section

The upper reservoir and dam of the Ffestiniog Pumped-Storage Scheme in north Wales.The power station at the lower reservoir has four water turbines which can generate 360 megawatts of electricity within 60 seconds of the need arising. The water of the upper reservoir (Llyn Stylan) can just be glimpsed on the right.

Hydroelectricity, or hydroelectric power, is a form of hydropower, (i.e.,the use of energy released by water falling, flowing downhill, moving tidally, or moving in some other way) to produce electricity. Specifically, the kinetic energy of the moving water is converted to electrical energy by a water turbine driving a generator. Most hydroelectric power is currently generated from water flowing downhill, but a few tidal harnesses exist that draw power from the tide. Hydroelectric power is generated at dams or other places where water descends from a height, or coasts with a large tidal swing (such as the Bay of Fundy). Hydroelectricity is a renewable energy source, since the water that flows in rivers has come from precipitation such as rain or snow, and tides are driven by the rotation of the earth. Hydroelectric dam diagram This image comes from: http://www. ... Hydroelectric dam diagram This image comes from: http://www. ... The upper reservoir (Llyn Stwlan) and dam of the Ffestiniog Pumped Storage Scheme in north Wales. ... The upper reservoir (Llyn Stwlan) and dam of the Ffestiniog Pumped Storage Scheme in north Wales. ... National motto: Cymru am byth (Welsh: Wales for ever) Waless location within the UK Official languages English(100%), Welsh(20. ... Hydraulic turbine and electrical generator. ... Water (from the Old English word wæter) is a colorless, tasteless, and odorless substance that is essential to all known forms of life and is known also as the most universal solvent. ... The tide is the regular rising and falling of the oceans surface caused by changes in gravitational forces external to the Earth. ... Electricity is a property of certain subatomic particles (e. ... Kinetic energy (also called vis viva, or living force) is energy possessed by a body by virtue of its motion. ... Kaplan turbine and electrical generator cut-away view. ... Insert non-formatted text here // Headline text Bold text:Generator redirects here. ... Tidal power is a means of electricity generation achieved by capturing the energy contained in moving water mass due to tides. ... Scrivener Dam, Canberra Australia, was engineered to withstand a once-in-5000-years flood event A dam (a common Teutonic word, compare to Dutch dam, Swedish and German damm, and the Gothic verb faurdammjan, to block up) is a barrier across flowing water that obstructs, directs or retards the flow... The Bay of Fundy is a bay located on the Atlantic coast of North America, on the northeast end of the Gulf of Maine between the provinces of New Brunswick and Nova Scotia. ... Renewable energy (sources) or RES capture their energy from existing flows of energy, from on-going natural processes, such as sunshine, wind, flowing water, biological processes, and geothermal heat flows. ... For the Second World War frigate class, see River class frigate The Murray River in Australia A river is a large natural waterway. ... Rain Rain is a form of precipitation, other forms of which include snow, sleet, hail, and dew. ... This page is about the form of precipitation. ...

The energy that may be extracted from water depends not only on the volume but on the difference in height between the water crest (or source) and the water outflow. This height difference is called the head. The amount of potential energy in water is directly proportional to the head. For this reason, it is advantageous to build dams as high as possible to produce the maximum electrical energy. In fluid dynamics, head refers to the constant right hand side in the incompressible steady version of Bernoullis equation. ... Potential energy (U, or Ep), a kind of scalar potential, is energy by virtue of matter being able to move to a lower-energy state, releasing energy in some form. ... This article is about proportionality, the mathematical relation. ...

While many hydroelectric schemes supply public electricity networks, some projects were created for private commercial purposes. For example, aluminium processing requires substantial amounts of electricity, and in Britain's Scottish Highlands there are examples at Kinlochleven and Lochaber, designed and constructed during the early years of the 20th century. Similarly, the 'van Blommestein' lake, dam and power station were constructed in Suriname to provide electricity for the Alcoa aluminium industry. General Name, Symbol, Number aluminium, Al, 13 Chemical series poor metals Group, Period, Block 13 (IIIA), 3, p Density, Hardness 2700 kg/m3, 2. ... The Scottish Highlands are considered to be the mountainous regions of Scotland north and west of the Highland Boundary Fault. ... Kinlochleven is a village in Scotland and lies at the eastern end of Loch Leven, a sea loch cutting into the western Scottish Highlands. ... Lochaber (Scottish Gaelic, Loch Abar) refers to a large area of the central and western Scottish Highlands. ... The backbone of Surinames economy is the export of alumina and small amounts of aluminum produced from bauxite mined in the country. ... Alcoa (NYSE: AA) is an American company and one of the largest producers of aluminum. ...

In most parts of Canada (the provinces of British Columbia, Manitoba, Ontario, Quebec and Newfoundland and Labrador) hydroelectricity is used so extensively that the word "hydro" is used to refer to any electricity delivered by a power utility. The government-run power utilities in these provinces are called BC Hydro, Manitoba Hydro, Hydro One (formerly "Ontario Hydro"), Hydro-Québec and "Newfoundland Hydro" respectively. Motto: Splendor Sine Occasu (Splendour without diminishment) Other Canadian provinces and territories Capital Victoria Largest city Vancouver Lieutenant Governor Iona Campagnolo Premier Gordon Campbell (BC Liberal) Area 944,735 km² (5th)  - Land 925,186 km²  - Water 19,549 km² (2. ... Motto: Gloriosus et Liber (Glorious and free) Other Canadian provinces and territories Capital Winnipeg Largest city Winnipeg Lieutenant Governor John Harvard Premier Gary Doer (NDP) Area 647,797 km² (8th)  - Land 553,556 km²  - Water 64,241 km² (14. ... Motto: Ut Incepit Fidelis Sic Permanet (Loyal it began, loyal it remains) Other Canadian provinces and territories Capital Toronto Largest city Toronto Lieutenant Governor James K. Bartleman Premier Dalton McGuinty (Liberal) Area 1,076,395 km² (4th)  - Land 917,741 km²  - Water 158,654 km² (14. ... During the 1960s, a terrorist group known as the Front de libération du Québec (FLQ) launched a decade of bombings, robberies and attacks on government offices. ... Motto: Quaerite Primum Regnum Dei (Seek ye first the kingdom of God) Other Canadian provinces and territories Capital St. ... Electricity is a property of certain subatomic particles (e. ... BC Hydro is the major provider of electricity in British Columbia. ... Founded in 1961, Manitoba Hydro is the electric power and natural gas utility in the province of Manitoba, Canada. ... Hydro One Incorporated delivers electricity across the Canadian province of Ontario. ... Hydro-Québec headquarters in downtown Montreal, with logo Hydro-Québec is a government-owned corporation that provides hydroelectric power for Quebec, Canada. ...

Importance

Hydroelectric power, using the potential energy of rivers, now supplies 20% of world electricity. Norway produces virtually all of its electricity from hydro, while Iceland produces 83% of its requirements(2004), Austria produces 67 % of all electricity generated in the country from hydro (over 70 % of its requirements). Apart from a few countries with an abundance of it, hydro capacity is normally applied to peak-load demand, because it can be readily stored during off-peak hours (in fact, pumped-storage hydroelectric reservoirs are sometimes used to store electricity produced by thermal plants for use during peak hours). It is not a major option for the future in the developed countries because most major sites in these countries having potential for harnessing gravity in this way are either being exploited already or are unavailable for other reasons such as environmental considerations. 2004 is a leap year starting on Thursday of the Gregorian calendar. ... Diagram of the TVA pumped storage facility at Racoon Mountain Pumped storage hydroelectricity is a method of storing and producing electricity to supply high peak demands by moving water between reservoirs at different elevations. ...

Advantages and disadvantages

The chief advantage of hydro systems is elimination of the cost of fuel. Hydroelectric plants are immune to price increases for fossil fuels such as oil, natural gas or coal, and do not require imported fuel. Hydroelectric plants tend to have longer lives than fuel-fired generation, with some plants now in service having been built 50 to 100 years ago. Labor cost also tends to be low since plants are generally heavily automated and have few personnel on site during normal operation. Oil is a generic term for organic liquids that are not miscible with water. ... Natural gas rig Natural gas (commonly refered to as gas in many countries) is a gaseous fossil fuel consisting primarily of methane. ... Coal is a fossil fuel extracted from the ground either by underground mining, open-pit mining or strip mining. ...

Hydroelectric plants generally have small to negligable emissions of carbon dioxide and methane due to reservoir emissions, and emit no sulfur dioxide, nitrogen oxides, dust, or other pollutants associated with combustion. Since the generating units can be started and stoppped quickly, they can follow system loads efficiently, and may be able to reshape water flows to more closely match daily and seasonal system energy demands. Hydroelectric plants with reliable hydrological histories are dispatchable and can be considered firm capacity. Consequently, in normal water years hydroelectric plants designed for a firm load will have a useful amount of surplus energy that may be exportable if transmission is available. Carbon dioxide is an atmospheric gas composed of one carbon and two oxygen atoms. ... The simplest hydrocarbon, methane, is a gas with a chemical formula of CH4. ... Sulfur dioxide (or Sulphur dioxide) has the chemical formula SO2. ... Dust is a general name for minute solid particles of diameters less than 500 micrometers (otherwise see sand or granulates) and, more generally, for finely divided matter. ...

Pumped storage plants currently provide the most significant means of storage of energy on a scale useful for a utility, allowing low-value generation in off-peak times (which occurs because fossil-fuel plants cannot be entirely shut down on a daily basis) to be used to store water that can be released during high load daily peaks. Operation of pumped-storage plants improves the daily load factor of the generation system. Diagram of the TVA pumped storage facility at Racoon Mountain Pumped storage hydroelectricity is a method of storing and producing electricity to supply high peak demands by moving water between reservoirs at different elevations. ... Load Factor (Aerodynamical): The load factor is a measure of how much the loading (G Force) of an aircraft is increased during manoeuvres. ...

Reservoirs created by hydroelectric schemes often provide excellent leisure facilities for water sports, and become a tourist attraction in themselves. Multi-use dams installed for irrigation, flood control, or recreation, may have a hydroelectric plant added with relatively low construction cost, providing a useful revenue stream to offset the cost of dam operation. There are a large number of sports that involve water. ...

In practice, the utilization of stored water is sometimes complicated by demand for irrigation which may occur out of phase with peak electricity demand. Times of drought can cause severe problems, since water replenishment rates may not keep up with desired usage rates. Minimum discharge requirements represent an efficiency loss for the station if it is uneconomic to install a small turbine unit for that flow. Irrigation in the Heart of the Sahara Irrigation (in agriculture) is the replacement or supplementation of rainfall with water from another source in order to grow crops. ...

Concerns have been raised by environmentalists that large hydroelectric projects might be disruptive to surrounding aquatic ecosystems. 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 smolt are also harmed on their migration to sea when they must pass through turbines. This has led to some areas barging smolt downstream during parts of the year. Turbine and power-plant designs that are easier on aquatic life are an active area of research. Environmentalism is activism aimed at improving the environment, particularly nature. ... In ecology, an ecosystem is a naturally occurring assemblage of organisms (plant, animal and other living organisms—also referred to as a biotic community or biocoenosis) living together with their environment (or biotope), functioning as a unit of sorts. ... The Atlantic Ocean is Earths second-largest ocean, covering approximately one_fifth of its surface. ... For other meanings of Pacific, see Pacific (disambiguation). ... World map showing location of North America A satellite composite image of North America North America is the third largest continent in area and fourth in population after Asia and Africa in area and population and Europe in population. ... The Chinook or King Salmon is the largest salmon in North America and can grow up to 58 long and 126 pounds. ... link title:This article is about biological spawning. ... Pool-and-weir fish ladder at Bonneville Dam on the Columbia River Fishways, most commonly referred to as fish ladders but also known as fish passes, are structures placed on or around man-made barriers (such as dams and weirs) to assist the natural migration of diadromous fishes. ... A young salmon at the stage intermediate between the parr and the grilse, when it becomes covered with silvery scales and first migrates from fresh water to the sea. ... Kaplan turbine and electrical generator cut-away view. ... Self propelled barge carrying bulk crushed stone A barge is a flat-bottomed boat, built mainly for river and canal transport of heavy goods. ...

Generation of hydroelectric power can also have an impact on the downstream river environment. First, water exiting a turbine usually contains very little suspended sediment, which can lead to scouring of river beds and loss of riverbanks. Second, since turbines are often opened intermittently, rapid or even diurnal fluctuations in river flow are observed. 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 preceding conditions. Finally, water exiting from turbines is typically much colder than the pre-dam water, which can change aquatic faunal populations, including endangered species. 1. ... Grand Cañon at the foot of the Toroweap - looking east, by William Henry Holmes The Grand Canyon is a colorful, steep-sided gorge, carved by the Colorado River, in northern Arizona. ... Glen Canyon Dam Glen Canyon Dam is a dam on the Colorado River at Page, Arizona. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... The American bison numbered as few as 750 in 1890 due to extreme overhunting. ...

The reservoirs of hydroelectric power plants may produce substantial amounts of methane and carbon dioxide. This is due to plant material in newly flooded and re-flooded areas being inundated with water, decaying in an anaerobic environment, and formating methane, a very potent greenhouse gas. The methane is released into the atmosphere once the water is discharged from the dam and turns the turbines. According to the World Commisssion on Dams report, where the reservoir is large compared to the dam capacity (less than 100 watts per square metre of surface area) and no clearing of the reservoir growth has occurred, effectively as much greenhouse gas may be released from a dam for electricity generation as for generating the equivalent amount of energy from burning oil [1]. The simplest hydrocarbon, methane, is a gas with a chemical formula of CH4. ... Carbon dioxide is an atmospheric gas composed of one carbon and two oxygen atoms. ... Increasing CO2 levels Greenhouse gases (GHG) are gaseous components of the atmosphere that contribute to the greenhouse effect. ...

Another disadvantage of hydroelectric dams is the need to relocate the people living where the reservoirs are planned. In many cases, no amount of compensation can replace ancestral and cultural attachments to places that have spiritual value to the displaced population. Additionally, historically and culturally important sites can be lost, as in the case of the Three Gorges Dam project. The Three Gorges Dam (Chinese: 三峡大坝; pinyin: ) spans the Yangtze River (third longest in the world) at Sandouping, Yichang, Hubei province, China. ...

Hydro-electric facts

Oldest

• Appleton, Wisconsin, USA completed 1882, A waterwheel on the Fox river supplied the first commercial hydroelectric power for lighting to two paper mills and a house, two years after Thomas Edison demonstrated incandescent lighting to the public. Within a matter of weeks of this installation, a power plant was also put into commercial service at Minneapolis.
• Duck Reach, Launceston, Tasmania. Completed 1895. The first publicly-owned hydro-electric plant in the Southern Hemisphere. Supplied power to the city of Launceston for street lighting.

Appleton is a city in the U.S. state of Wisconsin. ... One of the periods of glaciation was also termed the Wisconsin glaciation. ... 1882 was a common year starting on Sunday (see link for calendar). ... The Fox River is a river in Wisconsin in the United States. ... Thomas Alva Edison Thomas Alva Edison (February 11, 1847 – October 18, 1931) was an American inventor and businessman who developed many important devices. ... The incandescent light bulb uses a glowing wire filament heated to white-hot by electrical resistance, to generate light (a process known as thermal radiation). ... This article is about the city in Minnesota. ... Duck Reach Power Station was the first publicly-owned hydro-electric plant in the Southern Hemisphere, and provided the Tasmanian city of Launceston with hydro-electric power from its construction in 1895 to its closure in 1955. ...

Largest hydro-electric power stations

Itaipu Dam

Itaipu Dam File links The following pages link to this file: Electricity generation Itaipu Hydroelectricity ... Itaipu Dam File links The following pages link to this file: Electricity generation Itaipu Hydroelectricity ...

Operational

• Itaipu, Brazil/Paraguay, completed 1983, 12,600 MW
• Guri, Venezuela, completed 1986, 10,300 MW
• Grand Coulee, USA, completed 1942, expanded in 1980 to 6,900 MW
• Sayano-Shushenk, Russia, completed 1983, 6,400 MW
• Robert-Bourassa, Canada, completed 1981, 5,616 MW
• Churchill Falls, Canada, completed 1971, 5,428 MW, expandable to 9,252 MW

Itaipu Dam Itaipu (Guarani: Itaipú; pronounced ) is a dam that includes the largest hydroelectric power plant in the world. ... 1983 is a common year starting on Saturday of the Gregorian calendar. ... The Guri Dam is one of the biggest in the world. ... 1986 is a common year starting on Wednesday of the Gregorian calendar. ... Grand Coulee Dam Grand Coulee Dam is a hydroelectric gravity dam on the Columbia River in Washington State, built by industrialist Henry J. Kaiser. ... 1942 was a common year starting on Thursday (link will take you to calendar). ... 1980 is a leap year starting on Tuesday. ... 1983 is a common year starting on Saturday of the Gregorian calendar. ... 1981 is a common year starting on Thursday of the Gregorian calendar. ... Churchill Falls, Labrador, Canada Churchill Falls are spectacular waterfalls, 245 ft (75 m) high, on the Churchill River in Labrador, Canada. ... 1971 is a common year starting on Friday (click for link to calendar). ...

In Progress

• Three Gorges Dam, China, First power July 2003,Scheduled completion, 2009, 18,200 MW

These are installed power figures. If rated by annual power production, the order is different. The Three Gorges Dam (Chinese: 三峡大坝; pinyin: ) spans the Yangtze River (third longest in the world) at Sandouping, Yichang, Hubei province, China. ... 2003 is a common year starting on Wednesday of the Gregorian calendar. ... 2009 is a common year starting on Thursday of the Gregorian calendar. ...

Countries with the most hydro-electric capacity

• Canada, 341,312 GWh (66,954 MW installed)
• USA, 319,484 GWh (79,511 MW installed)
• Brazil, 285,603 GWh (57,517 MW installed)
• China, 204,300 GWh (65,000 MW installed)
• Russia, 160,500 GWh (44,000 MW installed)
• Norway, 121,824 GWh (27,528 MW installed)
• Japan, 84,500 GWh (27,229 MW installed)
• India, 82,237 GWh (22,083 MW installed)
• France, 77,500 GWh (25,335 MW installed)

These are 1999 figures and include pumped-storage schemes.

References

1. New Scientist report on greenhouse gas production by hydroelectric dams.

See also

Wikimedia Commons has more media related to:

Hydroelectricity

• Hydropower
• List of energy topics
• wave power
• tidal power
• List of reservoirs and dams
• Tennessee Valley Authority
• Small hydro
• Pumped-storage hydroelectricity
• Environmental concerns with electricity generation
• William George Armstrong, 1st Baron Armstrong an early private hydro-electric station
• Roll on Columbia (song)

Wikipedia does not have an article with this exact name. ... The Wikimedia Commons (also called Commons or Wikicommons) is a repository of free content images, sound and other multimedia files. ... Hydraulic turbine and electrical generator. ... This list identifies articles and categories that relate to energy. ... Waves overtopping a test wave generator of the so-called Wave Dragon in Nissum-Bedding, Denmark. ... Tidal power is a means of electricity generation achieved by capturing the energy contained in moving water mass due to tides. ... The List of reservoirs and dams is a link page for any reservoir or dam in the world. ... President Franklin D. Roosevelt signs the TVA Act The Tennessee Valley Authority is a New Deal agency created to generate electric power and control floods in a seven-U.S.-state region around the Tennessee River Valley. ... Micro hydro in North-West Vietnam Small hydro is the application of hydroelectric power on a commercial scale serving a small community or medium sized industry. ... Diagram of the TVA pumped storage facility at Racoon Mountain Pumped storage hydroelectricity is a method of storing and producing electricity to supply high peak demands by moving water between reservoirs at different elevations. ... Modern technology uses large amounts of electrical power. ... William George Armstrong, 1st Baron Armstrong (November 26, 1810 - December 27, 1900) was an English industrialist, the effective founder of the Armstrong-Siddeley manufacturing empire. ... Roll on Columbia is an American folk song written in 1941 by American folk singer Woody Guthrie, who popularized the song through his own recording of it. ...

External links

• World Commission on Dams report on environmental and social effects of large dams, including discussion of greenhouse gas emissions
• Hydroelectricity - Water potential powered systems, focusing on non-impactive small hydro. (FreeEnergyNews.com)
• River Energy - river turbine systems, not dam. (FreeEnergyNews.com)