Hydroelectric power stations capture the energy in flowing water to produce electricity. The power stations are comprised of turbine generators and the structures necessary to channel and regulate the flow of water to the turbines.

Water flows from high points to low points because of the force of the gravity. Hydroelectric power systems capture some of the energy embodied in the flow of water and convert it into electrical energy. The power available in the flow of water in a given interval depends on two factors: the vertical distance that the water “ falls “ over the interval, measured in feet or meters, and the volume of flow of water, measured in cubic feet or cubic meters per second (cumecs).

If a dam is constructed to block the flow of water, a river or stream may be channelised through turbines connected to electric generators to produce power. The power produced by hydroelectric system is the product of three parmeters: the distance of water ‘ falls ‘ from the intake to the outlet, the volume of flow of water, and the efficiency of the turbine / generator equipment."

Hydroelectric plants can be divided into following categories:
  1. Run of the river schemes
  2. Weekly pondage schemes
  3. Monthly reservoir based schemes
  4. Seasonal plants
  5. Carry over reservoir schemes
  6. Micro and mini plants
  7. Major plants

Advantages of run of river schemes

In Run of the River Hydroelectric plants, energy from running water in the rivers is tapped and converted into electricity. Since the energy is directly tapped from the flowing water, these plants need minimal construction, and submerge least area. Normally a small barrage is built and if there is a local head, it is exploited. Such plants can be put in canals also. Many plants can be put up in a river. These plants normally do not need any storage area for reservoirs. They are ecologically sound. China has tapped its river water’s energy potential through a series of such plants. In our country, we have huge potential for generating energy through such run of the river / streams/ canal schemes. Even though these plants are seasonal, a well-developed grid can absorb the seasonality through a proper load generation balance.