Hydroelectricity & Tidal Barrages

• How is hydroelectricity generated

  As water flows a hydroelectric dam will trap the water in a reservoir

  Whenever water is released is released through the dam, it spins turbines which are connected to generators and so produces electricity

  The water can then return to the river
• How do tidal barrages generate electricity

  As the tide comes in a tidal barrage will trap the water upstream

  Once the tide has gone back out, water is released through the dam which spins turbines generating electricity
• Energy transfers that take place in dams and barrages

  GPE —> Kinetic energy —> Electrical energy
• 3 advantages of hydroelectricity


  Renewable

  Can increase or decrease output to match demand

  Cheap to run once set up
• 3 disadvantages of hydroelectricity

  Large environmental impact as the reservoir can disrupt the natural habitats

  Expensive to build

  Only possible regions with the right kinds of rivers
• Wave power

  Water in the sea rises and falls because of waves on the surface. Wave machines use the kinetic energy of this motion to drive electricity generators
• 3 advantages of wave power

  Renewable

  Cheap to run

  No polluting gases produced
• 2 disadvantages of wave power

  Difficult to scale up to designs for wave machines to produce large amounts of electricity

  Having many wave machines can negatively affect wildlife