Hydroelectricity & tidal barrages

• Hyrdroelectric dams

  As water flows downhill, a hydroelectric dam will trap water in man-made lake (reservoir).

  Whenever water released into dam, spins turbines which connect to generators, produce electricity.

  Water can return to river on downstream side of dam.
• Tidal barrages allow water to flow into bay / river during high tide, then release water during low tide.
• Water in higher side of dam contains grav potential energy.

  Once dam opened, transferred to kinetic energy as water rushes to lower side.
• As water moves past generators, some kinetic energy transferred to turbines - they spin.

  Generators use this energy to generate electrical power.
• Which energy transfer takes place as water flows from higher side of hydroelectric dam to lower side?

  Grav potential -> kinetic
• Advantages of hydroelectric dams?

  Renewable

  Higher electricity demands can be met by increasing water flow.
• Disadvantages of hydroelectric and tidal barrages?

  Can flood land upstream

  Upfront build costs high