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Transcript of RENEWABLE ENERGY
You've just arrived at the campsite for a friends camping trip.
You might be surprised to learn that even in these woods, you are surrounded by energy resources.
The sun warms the air, the wind blows, and heat from inside Earth warms the waters of the spring.
These sources of energy are all renewable
Scientists are trying to find ways to put these renewable energy resources to work to meet people's energy need. CAN YOU HELP?
We are going to do a project. You and a partner may choose one renewable energy source from a list that I will provide you.
After you have chosen which renewable energy source you will cover, you and your partner will be responsible for 2 things.
1.) putting together a presentation about how your renewable energy works, it's advantages, disadvantages.
2.) you and your partner will create a functioning model that demonstrates how your renewable energy source actually works.
What is renewable energy?
any naturally occurring, replaceable energy source that is not derived from fossil or nuclear fuel.
The sun streaming through the trees warms your face.
A breeze stirs, carrying with it the smell of a campfire.
Maybe you'll start your day with a swim in the warm water of a nearby hot spring.
The warmth you feel on a sunny day is solar energy, or energy from the sun
The sun constantly gives off energy in the forms of light and heat
In one day, Earth receives enough solar energy to meet the energy needs of the entire world for 40 years.
Solar energy does not cause pollution ANNNNDD it will not run out for billions of more years... ( at least that's what scientists say )
So if Solar Energy is so great, then why hasn't it taken the place of fossil fuels yet?
One reason is that solar energy is only available when the sun is shining. NO SUN, NO SOLAR POWER
In order to harness a useful amount of solar energy, we (humans) have come up with particular ways.
1.) Solar Power Plants
One way to capture the sun's energy involves using giant mirrors.
In a solar power plant, rows of mirrors focus the sun's rays to heat a tank of water
WHY DO YOU THINK THIS WOULD WORK?
The heat from the mirrors makes water boil, creating steam, which can then be used to generate electricity.
2.) Solar Cells
Solar energy can be converted directly into electricity using solar cells.
A solar cell has a negative and a positive terminal, like a battery.
Solar cells can power some calculators, lights,
and even houses.
3.) Passive Solar Heating
A passive solar system converts sunlight into thermal energy.
Passive solar heating
example is when you get into a really hot car during the summer.
Solar rays come into through the cars windows and heat the inside, trapping the heat inside the car. The same can be done for a house or building.
Mini Lesson time (YAY)
Solar Energy is the indirect source of water power... What does that mean?
Remember the water cycle?
Sun heats the water, water then vapors (evaporation), collects in the sky as clouds, precipitation (rain, snow, or hail) occurs, water is collected on the earth's surface... And round and round it goes :)
is electricity produced by flowing water.
A dam, is probably the most popular, or best know source of hydroelectric power.
Recognize this ?
The Hoover Dam is probably the most popular dam in the in United States, if not the world.
Met Water District of Southern California 28.54%
State of Nevada 23.37%
State of Arizona 18.95%
Los Angeles, California 15.42%
Southern California Edison Company 5.54%
Boulder City, Nevada 1.77%
Glendale, California 1.59%
Pasadena, California 1.36%
Anaheim, California 1.15%
Riverside, California 0.86%
Vernon, California 0.62%
Burbank, California 0.59%
Azusa, California 0.11%
Colton, California 0.09%
Banning, California 0.04%
How is the energy made using a dam?
A dam across a river blocks the flow of water, creating a body of water called a reservoir.
When a dam's control gates are opened, water flows through tunnels at the bottom of the dam.
As the water moves through the tunnels, it turns turbines, which are connected to generators.
Quick question for you... What is a turbine and generator?
a machine used for producing continuous power in which a wheel revolves quickly by a fast-moving flow of water, steam, gas, and air, then generating energy.
Today, hydroelectric power is the most widely used source of renewable energy.
But, WHY Mr. Wilson?
Unlike solar energy,
flowing water provides a
constant supply of energy.
Once a dam and power plant are built, producing electricity is inexpensive and does not create air pollution like fossil fuels.
have its flaws though...
1.) In the USA, most suitable rivers have already been dammed.
2.) Dams can have negative effects on the environment
How about now?
power derived from wind: used to generate electricity or mechanical power.
Like water power, wind energy is also an indirect form of solar energy.
What does that mean again?
The sun heats Earth's surface unevenly. As a result of this uneven heating, different areas of the atmosphere have different temperatures and air pressures. The differences in pressure cause wind as the air moves from one area to the next.
Much like water energy, wind can be used to turn a turbine.
So the way it all works
There are places called wind farms.
At these farms we are farming wind.
As stated in the video, wind power is the fastest growing energy source in the world!
Wind energy does not cause air pollution, though
it may have some noise pollution but it is manageable.
Also, in places where it is
difficult to bring in fuels,
wind energy can fill that
Wind power, like other energy sources
has its draw backs.
1.) Few places have steady blowing
winds, or enough to make a wind
2.) Wind generators are noisy
3.) To some, they are eye sores
Modern day advances are occurring. Let's watch this short clip and discuss some of the benefits and disadvantages of the idea...
energy made from living things, usually through the act of "burning."
Wood was the first fuel ever used for heat and light.
Other biomass fuels include:
As fossil fuel supplies shrink, people are taking a
closer look at biomass fuels.
For example, when oil prices rose in the early 1970s, Hawaiian sugar cane farmers began burning sugar cane wastes to generate electricity.
At one point, these wastes
provided almost 1/4 of the electricity
used on the island of Kauai, Hawaii!
Aside from being burned as fuel,
biomass materials can also be
converted into other fuels.
For example, corn
sugar cane, and other crops can be used to make alcohol.
Adding the alcohol to gasoline forms a mixture called gasohol.
a mixture of gasoline and alcohol used to create energy.
Gasohol can be used to fuel cars
Other uses for biomass fuels are:
1.) Bacteria can produce methane gas when they decompose biomass materials in landfills.
2.) That methane can be used to heat buildings.
3.) Crops, such as soybeans and corn, can produce oil that can be used as fuel, which is called biodiesel fuel.
Flaws in Biomass fuels
It takes time for new trees to replace those that have been cut down.
Production of methane is expensive
What's in the future?
Biomass fuels are not used widely
today in the USA. But as fossil
fuels become scarcer,
biomass fuels may play
a larger role in
meeting energy needs
Below Earth's surface are pockets of very hot liquid rock called magma.
In some places, magma is very close to the surface.
The intense heat from Earth's interior that warms the magma is called
In certain regions, such as Iceland and New Zealand, magma heats underground water to the boiling point.
In these places, the hot water and steam can be valuable sources of energy.
For example, In Reykjavik, Iceland, 90% of homes are heated by water warmed underground in this way.
Geothermal energy can also be used to generate electricity, as shown in this image...
Geothermal energy is
an unlimited source of
Disadvantages of Geothermal Energy:
1.) There are only a few places where magma comes close to the Earth's surface
2.) Deep wells are necessary.
Problem is, wells are expensive
Even with these
will play a major role
in the future of meeting
Now that you have
been introduced to
so many energy
sources, consider a
fuel with this description:
It burns clean, it creates no smog or acid rain, and it exists on Earth in large supply...
This ideal-sounding fuel is real-- It's Hydrogen
Unfortunately, almost all the hydrogen on Earth is combined with oxygen in water.
Pure hydrogen can be obtained by passing an electric current through water. But it takes more energy to obtain the hydrogen than is produced by burning it.
Still, scientists find hydrogen power promising.
The problem consists in that it is rather expensive, and finding the energy to create hydrogen poses a difficult situation.
Car manufactures are now developing cars that run on hydrogen fuel cells. These would produce water as emissions.
That water might then be used again as fuel. You can see that if scientists can find a way to produce hydrogen cheaply, it could someday be an important source of energy
Concentrated Hydrogen can be manipulated in very powerful ways. An example of that is the H-Bomb, or Hydrogen Bomb...