The hydro-energy is said to be an indirect source of solar energy as the enormous amount of water in rivers and oceans not only act as a big collector of solar energy but it has also great storage capacity for solar heat energy. This is because of the fact that water has high specific heat capacity.
Principle of hydro-electric generation
Hydro-electric energy is produced by storing water behind large dams. The stored water has released by opening ‘controlled valves’ in the dam to provide a constant flow of water through turbines. Here the potential energy of following water and then to mechanical energy to turn turbine. When the turbine rotates, the shaft also rotates. The shaft of turbine is connected to the coils of a dynamo. When the coils of the dynamo move, electricity is produced.
At present, a little more than 23% of the total power generation in our country is contributed by hydroelectricity.