Hydroelectric Power Plants

Most people wonder ‘How do we get electricity?’ Most of the electricity at home, not including batteries, comes from a power plant which has a group of huge generators.  These are enormous machines that contain coils of copper wire that spin past huge, powerful magnets causing electricity to flow in the wires.  This electricity is sent out through transmission lines to cities, businesses, and homes. 

Fossil Fuels

The generators require some form of power to spin them 24 hours a day.  In most parts of the world power plants burn coal or oil to heat huge tanks of water to the boiling point.  The steam builds up tremendous pressure and is directed at large turbines attached to the generators by big shafts.   Burning coal is a good, inexpensive way to make electricity, but it uses up our fossil fuels.  Someday we may run out.  It also causes lots of smoke to enter the atmosphere which harms the environment.  The worst damage is done by acid rain caused by sulfur dioxide in the smoke.  It kills forests, harms crops, weakens metal bridges, dissolves cement in buildings, and creates many other problems.  The second big problem is global warming due to all the carbon dioxide created by the constant burning of fuels.

A hydroelectric power plant does not use fuel; instead it uses the force of moving or falling water.  Water is a renewable resource.  Every time it rains or huge packs of snow melt, the water is replaced.  After the water goes through the hydropower plant it is still clean and usable for other purposes, like drinking, irrigation, or swimming.
Facts

Hydropower plants require lots of water, so they are usually built on big rivers.  Water has much more power if it falls a long distance or if it is really deep.  That is why most hydro dams are really tall.  Most are at least 60 feet tall and some, like Grand Coulee Dam, are over 300 feet tall.  Dams can store water in the huge reservoir above the dam after big rains and use it during the dry times.  They can also create more electricity during the day and less at night when there is not as much demand.

Building Hydroelectric Power Plants

Building hydro dams is a huge, expensive job.  Before they flood the reservoir, they have to cut down many trees or remove the farms. Then they have to build a huge dam and all the machinery in the power plant, which is connected to the dam.  For protection, so the water doesn’t rush all over the dam, they build special gates called spillways to get rid of flood waters safely. 

How the Power Plant Generates Electricity

To power the turbines they must build huge inlets called penstocks which are like tunnels that lead down to the propellers. This turbine is a huge pinwheel-like thing that is spun by water flow. The turbine has a long shaft going through the middle of it attached to the generator.  As mentioned earlier the generator has coiled, copper wire and magnets. Michael Faraday discovered electromagnetism. When the magnets spin around coils of copper wire, the magnets produce an electric current in the wire. The electricity goes out of the power plant, through power lines, and to your house.

The First Hydroelectric Power Plant

The first hydropower plants weren’t as good as today’s power plants. It wasn’t until 1882 that the first hydroelectric power plant began operation. On September 30, 1882 the first hydroelectric power plant began operation on the Fox River in Appleton, Wisconsin. H.F. Rogers named it the Appleton Edison Light Company because of Thomas Edison’s plans for an electric-producing station in New York. Edison’s idea was to have a steam powered plant to drive its generators. That didn’t work out so well. So eventually we moved onto hydroelectric power plants. The people who built the first hydroelectric power plant spent a lot of their time and their money building it unfortunately the plant only produced enough power to light a few buildings. By the early 20th century they discovered how to build better hydroelectric power plants to light big cities. The government started using dams.

Today’s power plants generate enough electricity to light a city! Now we have three different types of turbines. There’s the Pelton wheel, the Francis Turbine, and the Kaplan Turbine. They all basically work the same way, but each looks different. Hydropower saves fifty million barrels of oil every year.

The Future

In the future some people think that there is going to be more electricity to light cities and fewer power plants. While other people say prices to build/and operate power plants will become greater.

Who I Interviewed And What I Learned I interviewed Brian Johnson by phone on April 5, 2006. He is a middle school teacher in Naches, WA.  I interviewed Brian because he works a lot on wind energy and technology. Since wind energy is similar, I figured he might know something about hydroelectric energy. Mr. Johnson wanted to teach technology because computers, fixing small engines, and electrical items were his hobby when he was little. Most of the things he knows about technology he learned from preparing to teach it. He said, “Everything we use requires electricity. I have my students study energy generation. Without electricity we would not have all the necessities and luxuries. For projects with my students we study wind energy but the principles are the same. It  just uses air instead of water. Both use a generator to create electricity.” He told me that the movement of fluid over an armature (fan-like propeller) turns the turbine.  Inside the generator are many coiled wires and big magnets. As the coils turn through the magnet field the electrons are induced to move or flow and that creates electricity. Electrons aren’t created; they are induced by the magnetic field.

Bibliography “Faraday Follows in Franklin’s Footsteps” 3-30-06 <http://fi.edu/franklin/scientist/faraday.html> How do Circuits Work?  www.edu.pe.ca/kish/grassroots/elect/curcuit.htm 4-8-06 Johnson, Brian. Personal interview. April 5th, 2006 Raintree Steck-Vaughn Hydroelectric Power. Illustrated Science Encyclopedia Publications, 1997, Volume 10, Pp. 943-944. Solar Thermal Electricity Overview-The Future3-30-06 <europa.eu.int/comm/energy-transport/atlas/html.ulsteatech.html>+ The First Power Plant www.americaslibrary.gov/jb/gilded/jb-gilded-hydro-l.html 4-6-06

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