How do dams help in generating electricity?

Water stored in lakes at a high altitude has a lot of potential energy. Due to nature, it just flows into rivers. As a result, most of it's energy remains untapped. Dams are just walls to hold the water. If you don't hold up water, it cannot be streamlined to get an even flow. Now, you create a dam and thus get a working head. read more

In a dam, water is stored at a height ( that's why most dams are located in hilly areas or where there is good gradient) and is allowed to fall and passed through a hydro turbine to generate electricity. read more

Actually, hydroelectric and coal-fired power plants produce electricity in a similar way. In both cases a power source is used to turn a propeller-like piece called a turbine, which then turns a metal shaft in an electric generator, which is the motor that produces electricity. read more

In hydropower plants water released from the reservoir flows down a pipe and through a turbine, spinning it, which in turn activates a generator to produce electricity. The water may be released either to meet changing electricity needs or to maintain a constant reservoir level. read more