Non-conventional energy resources - Water energy and Tidal energy

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5. Water energy:

Water covers roughly around \(71 \%\) of the earth's surface, which is why the earth is termed the water planet or blue planet.

Earth's water cover

Electricity can be generated by harnessing the energy of flowing water.

The technique of harnessing water energy is called hydropower.

Electricity is generated from flowing water (i.e. in a river) or water flowing from a height (from mountains or dams). Hilly locations are ideal since there is a continuous flow of large amounts of water falling from high slopes. Hydroelectric power does not pollute the environment or generate waste.

Hydroelectric power plant

Hydropower plants convert the kinetic energy of flowing water into electricity. The process is referred to as hydroelectricity.

Working of a hydropower plant

A video on hydropower or hydroelectricity:

Important!

The Kallanai Dam, also known as Grand Anicut, is the world's fourth oldest dam, built in the \(2^{nd}\ century\ A.D.\) by King Karikala Chola of the Chola Dynasty (C.E). The dam is located on the river Kaveri, approximately \(20\ kilometres\) from Tiruchirapalli, and continues to serve the people of Tamil Nadu.

6. Tidal energy:

The energy obtained from the movement of water due to ocean tides is known as tidal energy.

Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted on the earth's oceans.

The tides create a fast-flowing body of water known as a tidal stream. Turbines are placed in these tidal streams. The turbine rotates when the tides hit the turbine, converting the tidal energy into electric energy.