A tidal power station is made by building a barrage across the mouth of a river. At high tide, the sea water is trapped behind the barrage.
At low tide, the water is allowed to flow back into the sea through a turbine. What is the useful energy change in a tidal power station?
electrical energy → energy of position (potential)
electrical energy → energy of motion (kinetic)
energy of motion (kinetic) → energy of position (potential)
energy of position (potential) → electrical energy
