a penstock (also called as steel liners or pressure
shafts, depending on the application),
is a conduit for water from the reservoir to flow downward to
the turbine propeller with the force of
turbine, with propeller blades attached to a shaft so
that the shaft rotates when
the blades move with the force of falling water. The shaft is attached to the
generator, that generates electricity when the shaft
rotates a series of magnets (the rotor).
The rotor rotates past coils of copper (the stator) wound outside
it. A magnetic field is created between the coil and the magnets, thereby
producing alternating current by moving
transformer inside the powerhouse that converts this
alternating current into a
higher voltage current
lines that carry the electricity.
Hydroelectric power plants are built on rivers where
there is sufficient drop in elevation. Hydroelectric
power is a renewable source that is non-polluting, has a long
life, lower costs of generation and operation, is
more efficient and provides other benefits such as
irrigation, flood control and water supply.