Hydro energy is electric power generated by use of running water. In olden days the force of running water was used to run mills for grinding corn, paper mills etc. The mechanical power of running water was used in its `raw’ form to directly rotate turbines attached to such mills. With modern technology the force of running water can be harnessed, converted into electric current and supplied through power lines into our homes. It all starts by setting up a hydro electric power plant.
A hydro electric power plant has three basic components namely running water, a dam and a generator. Such a plant is set up at place near a natural source of water, preferably fast moving water. A river, a lake or sea are ideal choices. A dam is a wall-like structure constructed across a river channel and acts as a barrier. The barrier results into accumulation of water thereby acting as a reservoir. Such a dam is thicker at the bottom than at the top since as water accumulates it exerts a lot of pressure at the bottom of the dam. If the dam is erected near a lake water is channeled into the dam through tunnels.
The rotating turbines are connected to a generator which converts the mechanical energy into an electric current. This electric current is in turn transferred to the transformer in the power house converting it into a usable form. Attached to the transformer are power lines that distribute electricity as we know it to our homes and businesses premises.
Once the hydro power plant is set up its running is done by use of the gravity force. There is no emission of gases or other impurity. It is renewable energy in the sense that the water stock in the reservoir can be replenished during rainy seasons. Despite the prohibitive cost of setting up a hydro electric power it still remains the main source of electric energy in the world.