HYDRO POWERHYDRO POWER

Hydro power has a long Hydro power has a long history. Until the early history. Until the early

twentieth century, water twentieth century, water powered mills ground powered mills ground grain into flour, sawed grain into flour, sawed lumber and performed lumber and performed numerous other tasks. numerous other tasks. Such direct usage is Such direct usage is now rare, and most now rare, and most

water power is used to water power is used to generate a convenient generate a convenient

secondary energy secondary energy source, electricity.source, electricity.

Hydro powerHydro power is available by creating dams in stream is available by creating dams in stream and river flows. Hydro power generation is an and river flows. Hydro power generation is an established technology and maybe as much as one fifth established technology and maybe as much as one fifth of the world's electricity is generated this way, which is of the world's electricity is generated this way, which is slightly more than by nuclear generation.slightly more than by nuclear generation.

Hydroelectric dam in cross section Hydroelectric dam in cross section

In electricity generation, an electrical generator is a device that converts mechanical energy to electrical energy, generally using electromagnetic induction. The source of mechanical energy may be a reciprocating or turbine steam engine, water falling through a turbine or waterwheel, an internal combustion engine, a wind turbine, a hand crank, compressed air or any other source of mechanical energy.

Large Dams such as Hoover Large Dams such as Hoover Dam are able to provide large amounts Dam are able to provide large amounts of hydroelectric power; it has a 2.07 of hydroelectric power; it has a 2.07 gigawatt capability.gigawatt capability.

Hoover Dam is among the Hoover Dam is among the most recognized and renowned most recognized and renowned structures built by the Bureau of structures built by the Bureau of Reclamation.  Reclamation.   The dam was authorized under the The dam was authorized under the Boulder Canyon Project.Boulder Canyon Project.

AdvantagesAdvantages

The major advantage of The major advantage of hydroelectricity is elimination hydroelectricity is elimination of the cost of fuel. The cost of of the cost of fuel. The cost of operating a hydroelectric plant operating a hydroelectric plant is nearly immune to increases is nearly immune to increases in the cost of fossil fuels.in the cost of fossil fuels.

Where a dam serves multiple Where a dam serves multiple purposes, a hydroelectric plant purposes, a hydroelectric plant may be added with relatively may be added with relatively low construction cost, low construction cost, providing a useful revenue providing a useful revenue stream to offset the costs of stream to offset the costs of dam operation. dam operation.

Economics

Since hydroelectric dams Since hydroelectric dams do not burn fossil fuels, do not burn fossil fuels, they do not directly they do not directly produce carbon dioxide produce carbon dioxide ((a greenhouse gasa greenhouse gas). ). While some carbon While some carbon dioxide is produced dioxide is produced during manufacture and during manufacture and construction of the construction of the project, this is a tiny project, this is a tiny fraction of the operating fraction of the operating emissions of equivalent emissions of equivalent fossil-fuel electricity fossil-fuel electricity generation.generation.

Greenhouse gas emissions

Reservoirs created by Reservoirs created by hydroelectric schemes hydroelectric schemes often provide facilities for often provide facilities for water sports, and become water sports, and become tourist attractions in tourist attractions in themselves. In some themselves. In some countries, farming fish in countries, farming fish in the reservoirs is common. the reservoirs is common. Multi-use dams installed Multi-use dams installed for irrigation can support for irrigation can support the fish farm with the fish farm with relatively constant water relatively constant water supply. supply.

Related activities

DisadvantagesDisadvantages

Hydroelectric projects can be disruptive to surrounding Hydroelectric projects can be disruptive to surrounding aquatic ecosystems. For instance, studies have shown aquatic ecosystems. For instance, studies have shown that dams along the Atlantic and Pacific coasts of North that dams along the Atlantic and Pacific coasts of North America have reduced salmon populations by preventing America have reduced salmon populations by preventing access to spawning grounds upstream, even though access to spawning grounds upstream, even though most dams in salmon habitat have fish ladders installed.most dams in salmon habitat have fish ladders installed.

Environmental damage

Population relocationPopulation relocation Another disadvantage of Another disadvantage of

hydroelectric dams is the hydroelectric dams is the need to relocate the need to relocate the people living where the people living where the reservoirs are planned. In reservoirs are planned. In many cases, no amount many cases, no amount of compensation can of compensation can replace ancestral and replace ancestral and cultural attachments to cultural attachments to places that have spiritual places that have spiritual value to the displaced value to the displaced population. Such population. Such problems have arisen at problems have arisen at the Three Gorges Dam the Three Gorges Dam project in China.project in China.

Dam failuresDam failures Failures of large dams, Failures of large dams,

while rare, are potentially while rare, are potentially serious — the Banqiao serious — the Banqiao Dam failure in Southern Dam failure in Southern China resulted in the China resulted in the deaths of 171,000 people deaths of 171,000 people and left millions and left millions homeless. Dams may be homeless. Dams may be subject to enemy subject to enemy bombardment during bombardment during wartime, sabotage and wartime, sabotage and terrorism. Smaller dams terrorism. Smaller dams and micro hydro facilities and micro hydro facilities are less vulnerable to are less vulnerable to these threats.these threats.

Made by : khushal rajpurohitMade by : khushal rajpurohitClass : 10Class : 10thth (B) (B)School : K.V. 1 (AFS) JODHPURSchool : K.V. 1 (AFS) JODHPUR