Tidal Power - Power from the Tides

Tidal Power Overview

Tidal power, or tidal energy, is a form of renewable energy that harnesses the movement of ocean tides to generate electricity. It is one of the most predictable and consistent sources of renewable energy, owing to the gravitational forces of the moon and the sun and the Earth's rotation.

How Tidal Power Works

There are three main methods of capturing tidal energy:

1. Tidal Barrages
• Large dams built across tidal estuaries.
• Water flows through turbines in the barrage as tides rise and fall, generating electricity.
• Example: La Rance Tidal Power Station in France.
2. Tidal Stream Generators
• Underwater turbines placed in fast-moving tidal currents.
• Operate like underwater wind turbines.
• Less environmental impact than barrages.
3. Dynamic Tidal Power (DTP)
• A theoretical method involving long dams built perpendicular to the coast.
• Exploits the phase difference in tidal waves to generate power.
• Not yet implemented at scale.

Advantages

• Predictable and reliable—unlike solar or wind, tidal cycles are regular.
• Renewable and sustainable.
• Low visual impact (especially underwater systems).
• Long-lasting infrastructure.

Challenges

• High upfront costs for infrastructure and installation.
• Limited suitable locations with strong tidal ranges or currents.
• Potential environmental impact on marine ecosystems and sediment movement.
• Maintenance in harsh marine environments can be difficult and costly.

Current Use and Future Potential

• Still a nascent technology compared to wind or solar.
• Countries like the UK, South Korea, and Canada are exploring large-scale deployment.
• Ongoing innovations are improving efficiency and reducing costs.