Wave Energy & Tidal Energy - Are they the same?

AbraKaDabra

Pardon my limited knowledge about electrical branch, I was just reading about wave energy. Whenever we talk about renewable sources of energy, we use the term 'tidal energy'. Are wave and tidal energy forms one and the same? Or these are two different processes?

Hi AbraKaDabra,
Wave energy is formed due to the sun's heat whereas Tidal energy is due to gravitatioal force of the moon on Earth...Both are used for generating Electricity from them....

Dear akd,
Both are different. Wave energy refers to the energy we can harness from the waves rippling in the seas, whereas tidal energy is the energy which is available in the rising and lowering of the tides. Waves are caused due to disturbances in the sea, namely wind, minor tremors, etc. Tides are formed by the effect of the moon's gravity over the oceans.
In both the cases, we do harness the energy of the water which is pushed out of the sea, and the retreating action of the same water due to gravitation of the earth.
Hope the point is clear.

As the others mention, tidal energy involves a rise (and later) fall of the whole sea level in that location. This can involve huge volumes of water. Generally a dam and reservoir are used to harness this. To start with the level in the reservoir is lower than the incoming (rising ) tide. The water is allowed to flow into the reservoir. Underwater turbines generate power as this happens. If there is no demand for the power at that time (Tides have their own schedules), half of the turbines generate power. This power is used to run the rest of the turbines as pump so that more water can be put into the reservoir. After the high tide , during neap tide the reservoir puts the water back into the sea. The turbines are bi-directional and produce power again. This way one can get power both coming and going!

Wave energy is at the surface. This leads to a periodic oscillation of the local level of water. Turbines are not useful much. Either a float operated lever turns a crankshaft attached to a generator or better a hollow tower housing a bi directional wind turbine is located in the sea bed near the shore with a generator. In the second case the rising and falling of the waves outside sets up an oscillating column of air inside the tower, which generates power with the bi directional turbine.