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Home > Physics > Energy matters > Generation of electricity


Generation of electricity

Pumped storage hydroelectric power station

In a hydroelectric power station water is stored behind a dam in a reservoir. This water has gravitational potential energy.

  • the water runs down pipes (potential to kinetic energy) to turn the turbine
  • the turbine is connected to a generator to produce electricity (kinetic to electrical energy)
Diagram of hydroelectric power station. Water is stored in a high level reservoir and flows down to a low level loch, powering turbines as it passes between the reservoir and loch.

At pumped storage hydroelectric stations water is pumped back into the reservoir when there are periods of low power demand. This is often when there is excess energy being produced by other power stations.

This stores energy and during higher demand periods the water can be allowed to flow back down to produce electricity just like a normal power station. Such a system saves energy and also can be turned on quickly at times of peak demand.

Diagram of hydroelectric power station. Water flows down from a high level reservoir to generate electricity. But during low level elecricity demand water is pumped back up to the high level reservoir.


Listen to this audio clip to find out about environmentally friendly alternatives to electricity.

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