1. © Oxford University Press 2011 IP1.21.5 Hydroelectric power station Hydroelectric power station

2. © Oxford University Press 2011 IP1.21.5 Hydroelectric power station A hydroelectric power station stores water behind a dam in a reservoir. A sluice gate is used to control the flow of water down the pipes to the turbines. The water turns the turbines and the generator produces electricity.

3. © Oxford University Press 2011 IP1.21.5 Hydroelectric power station This is the Hoover dam across the Colorado river in the USA. It is capable of generating 2 megawatts of power.

4. © Oxford University Press 2011 IP1.21.5 Hydroelectric power station This is a large turbine from a hydroelectric power station that drives the generators.

5. © Oxford University Press 2011 IP1.21.5 Hydroelectric power station A hydroelectric power station transforms the kinetic energy of flowing water into electrical energy. In order to control more easily the amount of energy produced, a dam is usually built. This stores the energy in the form of potential energy. Water in dam Gravitational potential energy Water flowing downhill Kinetic energy Turbines Kinetic energy Generator Electrical energy Energy transfer in a hydroelectric power station

6. © Oxford University Press 2011 IP1.21.5 Hydroelectric power station Advantages of hydroelectric power  Renewable energy resource  Does not need fuel  Can be stopped and started very quickly  Does not emit Carbon Dioxide

7. © Oxford University Press 2011 IP1.21.5 Hydroelectric power station Disadvantages of hydroelectric power  Building a dam can disrupt the aquatic life in the river.  Building a dam and hydroelectric power station requires a lot of land.  Dams can be very expensive to build.