Hydroelectricity & Tidal Barrages - How they Work | Pros & Cons

What is the common basic principle behind both hydroelectric dams and tidal barrages?

Both create a difference in water levels and use the resulting gravitational potential energy to spin turbines and generate electricity.

How does a hydroelectric dam generate electricity?

Water stored in a reservoir is released, flows through turbines, which drive generators to produce electricity, then the water returns downstream.

What triggers the operation of a tidal barrage?

The twice‑daily rise and fall of sea level (tidal cycles) caused mainly by the moon’s gravity, trapping water at high tide and releasing it when the tide falls.

List two major advantages shared by both hydroelectric dams and tidal barrages.

Large energy output & reliable electricity supply
• Zero pollution during operation (no harmful emissions)

Name three key disadvantages common to both systems.

Significant environmental impact (habitat loss, ecosystem change)
• High initial construction cost
• Barrier effects that block boats and fish migration

What are two hydroelectric‑specific concerns not shared with tidal barrages?

Flooding of large land areas, submerging habitats and villages
• Greater disruption to surrounding ecosystems due to the dam’s size