A typical hydroelectric dam has the following main parts:

• Water Reservoir: A large quantity of water is stored in a reservoir (or dam). The height or depth of the stored water determines how much electricity can be generated. As the depth increases, the generation of electricity also increases.

•  Gate: A control gate is used for releasing/blocking water from the dam. Depending upon the electricity requirements, the gate is opened.

• Penstock: The released water from the dam reaches the turbine blade through the penstock. The proper slope and diameter of the penstock is important for the efficiency of the dam.

• Turbine: The turbine consists of a number of large fan blades and a spindle. The spindle rotates when water strikes the blades. Thus the power of flowing water is converted to the rotational power of the spindle.

• Alternator: The spindle of the turbine is connected to the alternator, where rotational power of the spindle is converted into electrical power. The produced electricity is then distributed to the grid.

• River: The outflow of water from the turbine is released to a river.