Hydroelectricity & Tidal Barrages

This lesson covers:

1. How hydroelectric dams and tidal barrages work
2. How they transfer gravitational potential energy to kinetic energy
3. The pros and cons of each

Hydroelectric dams

electricity / downstream / turbines / reservoir / generator

1. As water flows downhill (e.g. from mountains), a hydroelectric dam will trap the water in a man made lake, which is also known as a .
2. Then whenever water is released through the dam, it spins which are connected to generators, and so produce .
3. The water can then return to the river on the side of the dam.

Tidal barrages work in a similar way to hydroelectric dams. However, instead of damming water that's flowed down from upstream like a conventional dam, a tidal barrage allows water to flow into a bay or river during tide, and then releases that water during tide.

Energy transfer in hydroelectric dams and tidal barrages

In both cases the water on the higher side of the dam or barrage contains lots of potential energy. Once the dam or barrage is opened, this energy is transferred to energy as the water rushes down to the lower side.

As the waters moves past , some of its kinetic energy is transferred to the turbines, causing them to start spinning. can then use this energy to generate electrical power.