A tidal barrage power station uses the movement of water during tides to generate electricity. At high tide, water is trapped in a basin behind a barrage. When the tide goes out, the trapped water is released, flowing through a tunnel to turn a large turbine connected to an electrical generator.
What type of energy store of the water decreases when the water flows from the basin to the turbine?
Describe how the turbine and generator produce electricity.
Suggest why it is important that the turbine rotates at a constant speed.
State the relationship between efficiency, useful energy output, and total energy input.
The efficiency of the tidal power station is 42%. The total energy input from the flowing water is 1250 MJ1250\text{ MJ}1250 MJ. Calculate the total wasted energy in MJ\text{MJ}MJ.
Name two forms of wasted energy in this system.