The rise and fall of the sea’s water level is known as a tide or a wave. Tides are caused by the moon’s attraction to sea water. Tides have a lot of potential energy, which is utilised to generate electricity. Flood tide occurs when the water level rises above the mean sea level. Ebb tide occurs when the water level falls below the mean level.
This system’s configuration is depicted in Figure. Ocean tides rise and fall, allowing water to be retained during the rise and released during the fall. A dam is built to separate the tidal basin from the sea, resulting in a difference in water level between the basin and the sea.
Water flows from the sea into the tidal basin through the water turbine during high tide. The tidal basin is higher than the tide height. As a result of being directly attached to a generator, the turbine unit runs and creates electricity.
Water flows from the tidal basin to the sea during low tide because the water level in the basin is higher than the tide in the sea. The running water also turns the turbine and generates electricity at this time.
Only when the sea level and the tidal basin level are equal does the power generation come to a halt. The generation of electricity from this kind of energy requires a certain minimum tidal height and a suitable location. The only examples of this sort of power plant are the 250 MW Kislaya power station in Russia and the Rance power plant in France.
Tidal power plants have a number of advantages.
1. It is pollution-free since it does not consume any fuel.
2. It is better than hydro-power plants in that it is completely rain-proof.
3. It increases the potential for fish farming in tidal basins and provides recreational opportunities for tourists and vacationers.
1. Tidal power plants can only be built if natural locations on the bay are accessible.
2. Because the sites are located on bays that are always far from load centres, the generated electricity must be transferred across great distances. This raises the cost of transmission as well as the transmission losses.