Hydroelectric

we start our process of hydroelectric energy at a dam. A dam is built to trap water, usually where a lake exists. Water can only flow through tunnels in the dam and then it dose it turns that turbine then drives the generators to create electricity. The dam is thicker at the bottom than at the top. That is because the pressure of the water is greater at the bottom of the dam. Hydro-electric power stations can produce a great deal of power and it is very low in cost.
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  • Unlike many other forms of energy power generation is on hand when needed in case of hydroelectricity. In a hydroelectric power plant, starting the turbine or stopping it only takes a few minutes (sometimes even seconds).
  • The operational cost is quite low and it is also a clean way of producing energy.
  • The large volume of water in the reservoir often serves the purpose for recreational activities such as water sports, etc.

disadvantages
  • in some cases, constructing a reservoir or damming a river at a certain location may have ecological effects on its surroundings.
  • Droughts can have a severely impact on hydroelectric power generation.
  • Silt is a problem that affects quite a few reservoirs, the respective hydroelectric power plants as well.

threegorgesdam.jpg
three gorges dam built in 2000
Expected investment: 203.9 billion renminbi (US$24.65 billion)