What Is Tide & Wave Energy?

The immense force of ocean waves and tides can be harnessed to create electricity.

The flow of water in rivers and the ocean contains vast amounts of untapped energy. By harnessing the massive power of the world's water, machines based on simple turbine designs can cleanly and inexpensively transform raw natural forces into usable electricity.

Barrage

Barrages work through a concrete structure built across an estuary or bay. Turbines underwater in the structure are turned by the tide going out and coming in, generating electricity. However, this method disrupts the normal water levels caused by tides, potentially damaging to the ecosystem. Additionally, the generators only work for the 10 hours of each day when the tide is active.

Offshore Turbine

Offshore turbines are mounted on metal structures in the ocean. These turbines look like propeller blades and are turned by the ocean's tides. This makes them similar in function to windmill generators, except that the regularity of tides makes them more predictable than turbines dependent on wind. Similar to the barrage generator, offshore turbines are limited to the time of day that tides are active.

Wave Power

Wave-powered generators use the up-and-down oscillation of waves to generate power. Waves hit moving parts on the generator, which are connected to turbines. The turbines convert the force of the wave hitting them into electricity. Although they are not restricted by the tide like tidal generators, wave power generators are less predictable.

References

• Energy Savers: Ocean Tidal Power
• Andy Darvill's Science Site: Wave Energy
• Andy Darvill's Science Site: Tidal Power
• Energy Saves: Ocean Wave Power