ABSTRACT
Hydroelectric power generation does not create new energy. Instead, it converts the kinetic energy of water in motion into electricity.7 Hydroelectric dams store water in a reservoir so that it can be released as needed to generate a regular power supply. Dams also create a head (defined as the distance water drops between its top and bottom elevations), which increases the force of the water’s movement. Inside a hydroelectric plant, a pipe called a penstock carries water from the reservoir to a turbine. When rushing water spins the blades of the turbine, kinetic energy is transformed into mechanical energy. The turbine then turns a rotor in the generator, which converts mechanical energy into electricity using the process discovered by Michael Faraday in 1831.8
Hydroelectric Dam
FIGURE 4.1 Diagram of a conventional hydroelectric dam. Graphic by the Tennessee Valley Authority.
