Two distinct methods for harnessing energy from the ocean are tidal energy and wave energy. Tidal energy utilizes the rise and fall of tides, while wave energy captures the kinetic energy of ocean waves.
1. Tidal Energy:
How it works:
Tidal energy harnesses the energy from the periodic rise and fall of tides, which are caused by the gravitational pull of the moon and sun.
Techniques:
Tidal barrages: These are like dams built across bays or estuaries to trap water during high tide and release it during low tide, driving turbines to generate electricity.
Tidal turbines: These are underwater turbines that capture the kinetic energy of tidal currents, much like wind turbines but underwater.
Example:
Tidal turbines are a common way to harness tidal energy, currently representing the most common type of tidal energy converter.
2. Wave Energy:
How it works:
Wave energy uses the kinetic energy of ocean waves to generate electricity.
Techniques:
Buoys and turbines: Floating buoys and turbines can be used to capture wave energy, with the waves causing the buoys or turbines to move, which then rotates a generator.
Oscillating Water Columns (OWC): OWCs trap air in a chamber, and as waves move the water, they cause the air to be compressed and expanded, driving a turbine.
Example:
Floating wave energy converters like the Salter Duck are examples of devices that use the bobbing motion of waves to power a pump that generates electricity.