There are three main sources of large amounts of energy in large bodies of water. These are, tidal motion, wave motion and thermal storage.
For a long time, large bodies of water have been used as heat sinks i.e. to cool equipment, buildings, industrial operations etc. The reverse has not been utulised as much however due to the fact that most bodies of water are below the ambient temperatre required. Therefore, obeying thermodynamics, it is not posible to harness the thermal mass of large bodies of water.
Tidal motion is controlled by the movement of the moon relative to the earth. Tidal motion can move very large bodies of water in a moderate timescale relative to the local geography. Clearly, such large mass movements require significant amounts of energy. As a result, it is possible to utilise this mass shift to generate electricity via mechanical means.
Wave motion is controlled by the varying metereological air pressures, air temperatures and water temperatures. Seabed geometry yield how waves build up and break when they approach rising land. Although wave motion is not as predictable as tidal motion, the moderate sized masses of fluid can be utilised to drive a mechnical system which then drives a generator.
In isolation, tidal and wave motion energy benefits are debatable. In combination, the product of the benefits outweigh the ever rising costs of electricity production.
Advantages Of Tidal Power
1. Tidal Energy Is Renewable
Tidal power is a results of the gravity from both the sun and the moon, combined with the earth’s rotation around its axis. These gravitational are unlikely to disappear any time soon, so you can safely say that Tidal Power is 100% renewable
Apart from the initial construction, tidal energy does not cause any harmful effects to the environment.
Tidal movements are predictable like clockwork. Scientists can predict exactly the moments high and low tide far in the future. It’s a huge advantage in comparison to solar panel installations or wind energy.
4. Long Lifespans
One of the oldest tidal power stations is in La Rance, France and has been operating since 1966. It still provides enough electricity to power the city of Rennes with more than 200,000 inhabitants. Compare this with the maintenance and high replacement costs of wind and solar energy. Tidal power is truly sustainable and is a long-term winner.