Influence of gravity causes water to flow downhill Rivers run downhill, lakes are made when water runs downhill into a reservoir of some type, either manmade or natural, water sheds are made from rainwater running off of hills into streams and riversThe kinetic energy of water flowing downward is what is used to power a turbine, just like the heat produced by nuclear reactions, and the heat used in geothermal power plants
Note: penstock allows water to flow downhill through the dam structure. The downward motion turns the turbine to produce electricity. The water then continues to flow down the river. Easiest places to build hydroelectric power stations is where nature already has this “step-down” in place: waterfalls, but we can create this by making a dam to cause the same effect as a waterfall.
Hydroelectric power is responsible for 20% of the world’s electricity and 88% of renewable energy worldwide. Nations like Norway and Brazil get a large percentage of their electricity from hydroelectric power.South America: Amazon River
Note: other purposes include tourist attraction for economic stimulus, dams can control the intake to match how much energy is needed, excess water can be used for farming irrigation, store potential energy for when more energy is needed
Hoover Dam triggered earthquakes due to the tremendous amount of strain the dam put on the surrounding area, other problems include political fallout from one country building a dam causing a neighboring country’s water supply to be cut down, a dam causes the natural landscape to be destroyed and residents of that area must move out to avoid the resultant flooding of their valley due to hydroelectric dam construction.
Hydroelectric Energy<br />May 17, 2010<br />
Objectives<br />Determine what causes hydroelectric power to produce electricity<br />Describe how a hydroelectric power plant produces electricity<br />List advantages and disadvantages of hydroelectric power<br />
Where does hydroelectric energy come from?<br />“Hydro-” means water<br />“-electric” means electricity<br />Hydroelectric energy is electricity gained from flowing water<br />
How does water produce electricity?<br />Water is influenced by gravity<br />That tendency can be used to turn a turbine<br />
Hydroelectric Dams<br />Three Gorges Dam in China is the largest hydroelectric plant in the world<br />
Hydroelectric Dam<br />Grand Coulee Dam in the state of Washington is the largest in the US<br />
Hydroelectricity from the Tides<br />Ocean Tides can produce hydroelectricity<br />Uses the motion and speed of the waves to power a turbine<br />
Advantages of Hydroelectric Power<br />Hydroelectric Power Stations can last for many decades<br />Hydroelectric energy does not pollute the atmosphere<br />Hydroelectric Dams can be used for other purposes<br />
Disadvantages of Hydroelectric Power<br />Dams are expensive to build and take a long time to repay the investment<br />If a dam is not built correctly, the dam could break causing serious flooding and damage downriver<br />Large dams can cause geological problems<br />