Hydro Power Production of Electricity Energy:
Hydro Electricity is produced by the building of a dam on large rivers;
this creates a large lake or reservoir behind the dam, this storage is the energy supply for making electricity. Depending on the geography these man-made lakes can cover 1,000s of sq. miles and contain a huge volume of water.
Near the bottom of the dam wall there is a water intake that is connected to the penstock,
a pipe or channel directing the water flow. Gravity causes the water to fall or flow through the penstock; hydrologic power is generated by the force, or weight, of water from the higher elevation
through the penstock to a lower elevation.
(Courtesy of the Tennessee Valley Authority)
The Water Wheel:
At the end of the penstock is a water wheel or turbine,
the penstock directs the water on to the paddles of the wheel
which forces it to spin at a very high speed. The spinning central shaft of the turbine is connected to a generator
which produces the electricity energy. This power is sent to transformers where it is converted to Alternating Current (AC) three phase and sent down transmission lines called the Power Grid System to your home.
(Drawing courtesy of U.S. Army Corps of Engineers)
Hydro Electricity Production:
Hydro Electricity Power Plants produce 20 percent of the world's electricity
with a combined output of 675,000 megawatts of power and supply more than 1 billion people with electricity energy. Hydro Electricity is the most efficient
and may seem to be the cleanest electricity energy source in comparison to fossil fuels type electricity energy generators, however due to the size and volumes of water required for storage they do have a significant impact on the local environment. Ecosystems in the area are affected by the increased in water levels on the storage side of the dam as well as the controlled lower water levels downstream. For more detailed information USGS Hydro Electricity