Green Energy   Nov 20, 2007   2:00/1:00 MT/PT
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lightbulbWHAT IS ENERGY?

     Energy is the ability to do work. Work can be carrying, moving or lifting something, warming something, or lighting something. Energy is needed to make our world work.

KINDS OF ENERGY
     Energy comes in many different forms --heat (thermal energy), light (radiant energy), mechanical, electrical, chemical, and nuclear energy. All forms of energy are stored in different ways. These sources are divided into two groups -- renewable (an energy source that we can use over and over again) and nonrenewable (an energy source that we are using up and cannot recreate in a short period of time.)

    nuclear power
Today we get most of our energy from NONRENEWABLE ENERGY sources. These include the fossil fuels -- oil, natural gas, coal, and nuclear energy. Fossil fuels were formed over millions of years by heat from the Earth's core and pressure from rock and soil on the remains of dead plants and animals. Another nonrenewable energy source is the element uranium. Through a process of nuclear fission we split uranium's atoms to create the heat used to make electricity.

Petroleum      Natural Gas        Coal        Nuclear energy

sun
RENEWABLE ENERGYsources include solar energy, which comes from the sun and can be turned into electricity and heat. Geothermal energy from inside the earth, wind, biomass and hydropower from water and ocean tides are also renewable energy sources.

Renewable energy sources are also called GREEN ENERGY

Green Energy refers to a term that is used to describe energy that is produced and used in ways that are considered 'environmentally friendly." So, green energy must be renewable and non-polluting. This means that green energy will have two types of benefits.

First, it will reduce the impact of both delivery and production of the energy we use.
Second, it will reduce the emissions of the energy we use.

There are advantages and disadvantages to all sources of energy.
Some disadvantages are cost, pollution, danger, and availability.
Scientists are always looking for better sources of energy that might limit the disadvantages.

solar cells
hot springs
wind turbines
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     Solart PanelEnergy from the sun is called Solar Energy. We can all feel the heat from the sun. We can use this heat for our energy needs to heat buildings, or warm water. Small devices called, photovoltaic cells, can turn light energy straight into electricity. How do we harness the power of the sun? Just click here to learn more or visit Dr. E's Energy Lab from the US Department of Energy.

The sun is the most inexhaustible, renewable source of energy known to man.

     We can also get energy directly from the heat inside the earth. This is called Geothermal Energy. Miles below the earth's surface lies hot rock called magma. The heat from this rock rises to the earth's crust in certain spots and warms underground pools of water. Southern Idaho has many of these spots and scientists are developing ways to use this energy to heat homes, other buildings and swimming pools.

     EIA kids page has great information about Geothermal Energy. You can also watch a geothermal energy slide show.

Find out about Geothermal Energy Research at Idaho National Engineering and Environmental Laboratory

      Wind TurbinesWind Power
Windmills have been used for a long time to grind grains and pump water from wells. Modern windmills, called wind turbines, are now used to generate electricity. Wind turbines can be very big and built in groups known as a wind farm. Small wind turbines can be used to charge batteries To see how much electricity they produce and exactly how they work, just click here. This website has good photos of different kinds of turbines.

Hydroelectric Dam The water in rivers can also be used for energy! This is called hydropower. Dams create large lakes. Water from the lake flows through machines called turbines which are connected to generators that make electricity. Water has the power to make electricity for whole cities! For more about the power of water just click here.

     The oceans may eventually provide us with another source of energy. We may be able to use the ocean's tides and the ocean's waves. 70% of the earth's surface is covered with water...that's a lot of waves that can be used for energy! Learn more from The Energy Story.
    

 Tidal Power
There are three basic ways to use the ocean for its energy. We can use the ocean's waves, or use the oceans high and low tides, or we can use temperature differences in the water.

Tides and tidal power are caused by the gravitational pull of the moon and sun, and the rotation of the earth.

Near shore, water levels can vary up to 40 feet. Only about 20 locations in the world have good inlets and a large enough tidal range—about 10 feet— to produce energy that is considered economical.

Tidal power has been used for energy for a long time!

During the time when Rome had conquered England, tide mills were created to grind grain into corn for bread and other food.

     Biomass and Waste You may be surprised to learn that the countryside can provide excellent sources of energy. Dead trees, left-over crops, sawdust, and clippings can be used to produce electricity and fuel. These sources are called "biomass."

     The trash we produce everyday can also be used as fuel. When waste is burned in incinerators it gives off heat which can be used to make electricity or to heat buildings. If waste is buried in a landfill, the gas it gives off as it decomposes can be collected and used.

      To find out more about how wood, crops and trashcans provide energy for us, click  here.
 

Trash Can

    
There have been many  Pioneers in Energy. Read the biographies of people who have contributed to energy and science discovery, inventions and research.
 

     
      Now that you're becoming experts about energy, and alternative energy, you'll need to know some things you can do to "save energy. Follow Roofus as he shows you his energy efficient neighborhood.
 
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