Hydroelectric and tidal

• What are the two systems used to generate electrical power discussed in the video?

  Hydroelectric dams and tidal barrages
• How do hydroelectric dams and tidal barrages generate electricity?

  By using differences in water levels
• What is the main difference between hydroelectric dams and tidal barrages?

  What causes the difference in water levels
• What is created when water is trapped behind a hydroelectric dam?

  A reservoir
• What causes the cyclic rise and fall of sea levels in tidal barrages?

  The effect of the moon's gravity
• How often do high tides occur?

  Twice each day
• Where are tidal barrages typically placed?

  In estuaries where rivers meet the ocean
• What type of energy is converted into electricity in hydroelectric systems?

  Gravitational potential energy
• What happens to the water after it passes through the turbines in a dam?

  It flows back into the river
• What are the pros and cons of hydroelectric dams and tidal barrages?

  Pros:

  • Generate large amounts of energy
  • No pollution
  • Reliable electricity sources
  • Low running costs
  • Scalable for different sizes

  
  

  Cons:

  • Significant environmental impact
  • Flooding of large areas
  • Disruption of fish migrations
  • High initial setup costs
• What is a major environmental downside of hydroelectric dams?

  They often flood large areas
• How do hydroelectric dams affect fish migrations?

  They can stop fish from traveling
• What is a benefit of hydroelectric dams regarding electricity demand?

  They can provide immediate response
• What is a common characteristic of both hydroelectric dams and tidal barrages?

  They generate energy with no pollution
• What is the main reason for the high initial setup costs of hydroelectric dams and tidal barrages?

  The size and complexity of the structures
• How does the operation of hydroelectric dams differ from tidal barrages in terms of water source?

  Hydroelectric dams use upstream water, tidal barrages use tides