Electricity which is generated by using the force created by flowing water is usually called hydroelectric power.
In most cases hydroelectric power plants are installed at the base of huge dams where the reservoir supplies ample amounts of water to power the turbines.
The water from the storage reservoir of the dam is brought to the turbines thorough large steel pipes called penstocks. By the time water has reached the turbine, it has gained a tremendous amount of momentum. As the water strikes the blades of the turbine, a device somewhat similar to a paddle wheel, it causes the turbine to rotate at a very high speed. The shaft of the turbine drives a generator which produces the electricity by the shaft rotating in a magnetic field. The generated electricity is taken from the generator and supplied to surrounding areas through high voltage lines.
Most hydroelectric power installations consist of a number of turbines and generators just like a conventional steam –powered generating plant. The average hydroelectric plant can produce thousand of volts of electricity at a constant rate.
Although the principles of the operation of the turbine and the generator are the same in any hydraulic installation, the source of water is not always a dam. In many instances