Tidal Energy
Tidal energy is renewable source of hydro energy which is available due to rise and fall of tides which occurs twice a day. The tides are caused due to the gravitational attraction of moon and sun upon the rotating earth.
The highest level of tidal water is known as flood tide or high tide and the lowest level of tidal water is known as ebb tide or low tide. The level difference between high and low tides is called tidal range.
The tidal range varies from time to time, season to season and its location. The maximum tidal range occurs at the time of new and full moon called spring tides. The total tidal energy of the world is estimated to be 3 x 106 MW. However, only a fraction of this energy can be recovered.
Limitations of Tidal Energy :
- It is site specific and the tidal energy can be recovered economically on the locations where the tidal range is 5 m or more.
- The availability of tidal energy is variable , thus the power generation is highly fluctuating in nature.
- Turbines are needed which can operate with fluctuating heads.
- The marine life and ecology is affected in the region where the tide plants are located. It also affects the navigation system.
- In order to handle large volume flow rates of tidal water at low heads, tidal plants need to operate with several turbines in parallel.
- Sea water is corrosive.
Availability of Tidal Power in India and Locations :
In India the potential for tidal power generation exists in Gulf of Kutch in Gujarat and in Sunderban area of West Bengal. The tidal power plants can be established on rivers of Malta and Curzon Creek in this reason. Small tidal power plants can be located at Beledone Creek (WB), Durgadowni Creek (Sundarban area), Rakshakhali Creek and at Bhavnagar in the Gulf of Cambay. The power potential in Gulf of Kutch and Gulf of Cambay is estimated to 1000 MW and 7000 MW respectively.