Chapter+5

== =**Fossil Fuels - Section 1**= media type="youtube" key="IGqkAuvtlaA" height="344" width="425" align="center"
 * Fuel** is a substance that provides energy as a result of a chemical change.
 * Energy Transformation** is a change from one form of energy to another.
 * Combustion** is the burning of fuels for energy, changing chemical energy to energy of heat or light or motion...or ELECTRICITY!
 * Production of Energy** - Power Plants generate electricity by converting energy from one form to another.....like coal to electrical energy.

Hmmm.....I wonder if that is why there is so much carbon dioxide in the atmosphere.....Industrial Revolution....hmmmm.........
 * Fossil Fuels -** energy-rich substances formed from the remains of organisms. They are made of hydrocarbons, meaning they contain carbon and hydrogen atoms. During //combustion//, the carbon and hydrogen atoms combine with oxygen from the air to form carbon dioxide and water. Combustion releases energy in the form of heat and light.

Images retrieved from google 2/10/10
 * Three Main Fossil Fuels: Coal, Oil, and Natural Gas.**

Since fossil fuels take hundreds of millions of years to form, they are considered **nonrenewable resources**. The United States uses about 1/3 of all the oil produced in the world....wow!

=Renewable Sources of Energy - Section 2=

Harnessing the Sun's Energy
These use rows of giant mirrors to heat tanks of water. The water boils and produces steam. This steam is used to turn a turbine - converting the solar energy into mechanical energy. The turbine is connected to a generator which consists of powerful magnets with copper wire. The magnets turn inside the copper wire to create an electric current.
 * Solar Power Plants**

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 * Solar Cells** are able to convert solar energy directly into electricity. They have a negative and positive ends just like a battery. It takes 5000 palm sized solar cells to power one average sized house. WOW!
 * Passive Solar Heating** converts solar energy into thermal energy (HEAT!). The sun is used to heat the air. The heated air is then distributed using pumps or fans.
 * Active Solar Heating** captures the sun's energy then uses pumps and fans to distribute the heat. Light strikes the dark metal surface of the solar collector. Pipes in the collector carry water that absorbs the energy. The heated water flows to a tank and then the heat is distributed throughout the building.

[|MakeaSolarCooker!]

Hydroelectric Power
This is electricity produced by flowing water. A dam is used to created a body of water called a reservoir. The gates of the dams control the flow of water from the reservoir to the bottom of the dam. As the water moves through the gates and tunnels of the dam it turns turbines which are connected to generator - electricity is made!

Interesting Note! - Water power comes indirectly from solar energy. Remember the water cycle!

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Hydroelectric power is the most widely used source of renewable energy. It provides a steady supply of energy - unlike like the sun, which isn't always shining. Once built, a dam is also inexpensive and does not create air pollution. However, it is limited by the finite number of suitable rivers in the world. In the United States, most of these rivers have already been dammed. Dams can also have a negative effect on the physical environment. Can you think of some ways?

Capturing the Wind
Wind farms use many windmills to generate electricity. The wind turns the blades of the windmill which turn a turbine connected to a generator that creates electricity. Sounds familiar, right!

Wind energy also indirectly comes from solar energy. As the sun heats the Earth's surface, it heats unevenly. This uneven heating of the atmosphere creates different temperatures and air pressures. The differences in air pressure causes air to move from one place to another - WIND!

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Wind is the fastest growing renewable energy source in the world. It does not cause pollution and is very useful in places where it is difficult to transport fuels. However, few places have steady enough winds to provide sufficient energy. The generators can also be noisy and can be destroyed if wind is too strong. There are also questions about their effect on the physical environment.

Biomass Fuels
These are fuels that come from living things. Some examples are wood, leaves, food waste, and manure. As fossil fuel supplies diminish, people are looking more and more at biomass fuels as a source of energy.

Biomass materials can also be converted into other fuels. One well known example is when corn, sugar cane, and other crops are used to make alcohol. Adding the alcohol to gasoline forms a mixture called gasohol. Gasohol can be used as a fuel for cars. Also, bacteria can produce methane gas when they decompose organic matter in landfills. The methane produced can be used to heat buildings. Crops can also be used as a biodiesel fuel.

media type="youtube" key="sN68ef6trEs" height="344" width="425" The benefits of biomass fuels is that they are renewable and as other fuels become scarce these fuels will be more and more useful. However, it takes time for new trees to replace those that have been cut down. It also is expensive to produce alcohol or methane in large enough quantities to be useful.

Tapping the Earth's Energy - Geothermal Energy
This type of energy comes from the heat of the Earth's interior. Below the surface of the Earth, there are pockets of magma. In areas of the world like Iceland and New Zealand magma heats water to boiling. The hot water and steam can be used to generate electricity.

media type="youtube" key="rfUQy86ZMpQ" height="344" width="425" Geothermal energy is unlimited and cheap. However, it does have disadvantages. There are only a few places on the Earth where magma comes close enough to the surface. Elsewhere very deep well need to be drilled to use this energy, which is expensive. Despite this, geothermal energy will likely increase in use in the future.

The Promise of Hydrogen Power
Hydrogen - A fuel that burns cleanly, creates no smog or acid rain, and exists on the Earth in large supply. Sounds amazing, right!

The problem is almost all the hydrogen on the Earth is combined with oxygen to form water. In order to obtain pure hydrogen an electric current needs to be passed through water. It takes more energy to obtain hydrogen than is produced by burning it. Still, it could be promising.

Hydrogen power could help hydroelectric plants run at full power all the time. They could use excess electricity to produce hydrogen. Hydrogen could also be used to help solar power. Since solar power plants often generate more power than they need during the day, the excess coudl be used to produce hydrogen.

Finally, car makers are now developing cars that run on hydrogen fuel cells. These cells would produce water as emissions and the water could possibly be used again as a fuel. Hydrogen is a fuel that has a lot of potential and could play a large role in meeting our energy needs in the future.

**Nuclear Energy - Section 3**
The central core of an atom is called a //**nucleus**//. Reactions that take place in the nucleus are called //**nuclear reactions**//. There are two types of nuclear reactions, //**fission**// and //**fusion**//. Nuclear **fission** is the splitting of an atoms nucleus into two smaller nuclei. The continuation of this is called a nuclear chain reaction. In a nuclear chain reaction, lots of //**energy**// is released! That energy is released as //**heat**//....and can be used to //**generate electricity**//!
 * Fusion** is the combining of two nuclei to produce on nucleus.

media type="youtube" key="H3IHWvIGVjg" height="385" width="640" =Energy Efficiency & Conservation - Section 4= **Energy Effiency is the percentage of energy that is actually used to perform work. Heating and Coolling:** The main way to increase energy is through the use of insulation. Insulation is a layer of material that traps air and blocks the transfer of heat between the air inside and outside of a building. It can be made of fiberglass, recycled paper, and much more.
 * Lighting:** Most of the energy used in home lighting is lost. For example, only 10% of the electricity produced from an incandescent bulb becomes light, the rest is heat. Compact flourescent bulb use 1/4th the energy and produce the same amount of light.
 * Transportation:** You can reduce the energy used for transportation by developing better engines, better tires, reducing the number of cars on the road by using public transportation and carpooling.

You can reduce your personal energy use in many ways. See the link below. [|Great NPR story on energy conservation]
 * Energy Conservation means reducing energy use.**