by Kayla Sperosexternal image hydro%20electric%20power.gif


Hydroelectricity: How it Works


The source of energy for hydroelectrical power is moving water. A hydro dam is used to harness the energy from the moving water. The water first flows into a reservoir tank if it is not a moving body of water (i.e. a river), and from there the water flows into a pipe called a penstock. The pipe is slanted downwards, which makes the water push against propellers, which are also part of the turbine. The propellers cause the turbine to turn; creating mechanical energy. Mechanical energy is turned into electrical energy by a generator. The water then passes through an opening at the end of the penstock-called a draft tube- and flows back in to the river or lake.The electricity produced by the generator is transported to a by means of power lines, and then to homes Gravitational potential energy, the water cycle, and kinetic energy are the reasons why hydroelectricity is a source of energy. Gravity pushes down on the water so it will go through the penstock, kinetic energy from the water makes the propellers in the turbine move, and the water cycle replenishes the lake or river with water.

Definitions:

__hydroelectical__: using water to make electricity
hydrodam: a dam that is used to create electricity for people to use
This is the Syncrude Tailings Dam in Alberta, Canada. It is the largest dam in the world( amount of material to build dam).
This is the Syncrude Tailings Dam in Alberta, Canada. It is the largest dam in the world( amount of material to build dam).

reservoir tank: a part of a dam that is a large container used to collect water from a river; water will be used later to create electricity
penstock: a pipe in a dam used to transport water through the dam, therefore spinning the turbine
turbine: an engine that uses the kinetic energy from water to spin it and create mechanical energy
mechanical energy: energy created by moving parts in a machine
generator: a part of the hydrodam that converts the mechanical energy created by the turbine into useable electrical energy

This is a generator and turbine in a hydro dam.
This is a generator and turbine in a hydro dam.

gravitational potential energy: the potential energy of something based on how far it is from sea level; the higher the object, the more gravitational potential energy it gains
water cycle: the process that water goes through: evaporation, condensation, precipitation, etc; it is neverending
kinetic energy: energy that changes something
A couple helpful links that give lots of information about hydroelectricity:
U.S. Department of Energy- Efficient and Renewable Energy: http://www.afdc.energy.gov/afdc/
Planet Green- Run Your Home on Hydropower: http://planetgreen.discovery.com/home-garden/run-your-home-on-small-scale-hydropo.html

This is a diagram showing how a dam works with a moving river.
This is a diagram showing how a dam works with a moving river.


A video about the way a dam works: