2. From the 16th century, the power of falling water was utilized in Europe. In the early 18th century, the importance of water power replaced by the use of coal. From the late19th century, water power was harnessed to generate electricity ( called H.E.P. ) Hydropower is the most often used of the renewable energy source that generates electricity. 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. It is very popular because it is very cheap and clean.

3. -inexhaustible -pollution-free -high energy conversion efficiency -convenient transport( by grid network of transmission lines ) -can be incorporated into a multi-purpose water scheme, such as Three Gorges Dam Project Despite its advantages, H.E.P. contributes only a small percentage( 2 to 5% )to world energy consumption.

4. -great head of water -rivers with large volume of water and/or fast flow -regular and reliable water supply -presence of lakes -space for reservoir creation -presence of gorges for dam sites -lack of competition from coal, petroleum or other types of energy resource -large demand

5. -wildlife habitats and natural ecosystems will be disturbed -silting may occur -high cost of construction An American mining engineer Lester Pelton designed the first turbine to use water. The first hydroelectric power station was built in 1882, but it could only work 250 light bulbs.

6. The future expansion of H.E.P. development is likely to be checked because the best and most economic sites have all been developed

7. Location: Sandouping, Yichang, Hubei province Height: 181 meters Expected investment: 203.9 billion renminbi (US$24.65 billion) Number of migrants: 1.13 million Installed power generation capacity: 18.2 million kilowatts Functions: Flood control, power generation, improved navigation

10. ~ Hydro-Electric Power is a CLEAN energy source ~HEP is the most popular renewable energy source that generate electricity ~ An American mining engineer Lester Pelton designed the first turbine to use water ~ It is one of the oldest sources of energy and was used thousands of years ago