Transcript Energy - Effingham County Schools

Energy
Explain how fuels are used to generate electricity in an electric power plant.
Explain how fossil fuels form and how they are used.
Compare the advantages and disadvantages of fossil-fuel use.
Pre-assessment Questions
1. What is the difference between
renewable resources and nonrenewable
resources?
2. List as many renewable resources as
you can recall.
3. List as many nonrenewable resources as
you can recall.
2 Types of Energy
• Nonrenewable
• Renewable Energy
Energy Sources:
Sources: A resource
Resources that are
that can be used
not replaced or
continuously without
regenerated naturally
being used up.
within a reasonable
period of time.
Examples
(List as many as you can)
• Nonrenewable
• Renewable
1. Fossil fuels (coal, oil,
natural gas) 86% of US
energy use.
1. Solar Power
2. Uranium/ nuclear
power/Nuclear Fission
3. Water Power
3. Oil Shale (produces crude
oil and other flammable
gases)
5. Geothermal Power
4. Tar Sands (residue in rocks
used to make bitumen)
2. Wind Power
4. Ocean or Tidal Power
Resources vs Reserves
• Resources are amounts of material that
are known to exist and can be extracted
now or in the future with potential
technology. (Much larger amount and
some may be undiscovered)
• Reserves are known amounts of material
that can be extracted profitably with
present day technology
Energy Posters
• You will be assigned 1 of many nonrenewable resources. You may
use your energy packets as a resource as well as your books on pgs
359-363. Make sure your font is large enough for others to read.
Include a:
•
•
•
•
1. Title
2. Info explaining your energy
3. Discuss your ideas of the pros and cons
4. A picture to represent your energy source
1: Natural gas, 2: Petroleum, 3: Propane, 4: Coal, or
5:Uranium
Nuclear Power
• Objectives
• Describe nuclear fission.
• Describe how a nuclear power plant
works.
• List three advantages and three
disadvantages of nuclear energy.
• Fission: Splitting Atoms
Nuclear Energy
• In the 1950s and
1960s, nuclear power
plants were seen as
the power source of
the future because
the fuel they use is
clean and plentiful.
• Today, nuclear power
accounts for 17% of
the world’s electricity.
Fission: Splitting Atoms
• Nuclear power plants get
their power from nuclear
energy.
• Nuclear energy is the
energy released by a
fission or fusion reaction.
It represents the binding
energy of the atomic
nucleus.
• In nuclear power plants,
atoms of the element
uranium are used as the
fuel.
Fission: Splitting Atoms
• The nuclei of uranium atoms are bombarded
with atomic particles called neutrons. These
collisions cause the nuclei to split in a process
called nuclear fission.
• Nuclear fission is the splitting of the
nucleus of a large atom into two or more
fragments.
• Nuclear fission releases a tremendous
amount of energy and more neutrons,
which in turn collide with more uranium
nuclei.
How Nuclear Energy Works
• The heat released during nuclear reactions is
used to generate electricity in the same way that
power plants burn fossil fuels to generate
electricity.
• The energy released from the fission reactions
heats a closed loop of water that heats another
body of water.
• As the water boils, it produces steam that drives
a turbine, which is used to generate electricity.
The Advantages of Nuclear Energy
• Nuclear fuel is a very concentrated energy
source.
• Nuclear power plants do not produce airpolluting gases.
• Nuclear power plants release less radioactivity
than coal-fired power plants do, when operated
properly.
• Countries with limited fossil-fuel resources rely
heavily on nuclear plants to supply electricity.
Why Aren’t We Using More Nuclear
Energy?
• Building and maintaining a safe reactor is
very expensive.
• This makes nuclear plants no longer
competitive with other energy sources in
many countries.
• The actual cost of new nuclear power
plants is uncertain, so it is difficult to
predict whether investors will build new
plants in the United States.
Storing Waste
• The greatest disadvantage of nuclear power
is the difficulty in finding a safe place to
store nuclear waste.
• The fission products produced can remain
dangerously radioactive for thousands of
years.
• Storage sites for nuclear wastes must be
located in areas that are geologically stable
for tens of thousands of years.
• Scientists are researching a process called
transmutation, that would recycle the
radioactive elements in nuclear fuel.
Safety Concerns
• In a poorly designed nuclear
plant, the fission process can
potentially get out of control.
• The Chernobyl reactor was
destroyed in 1986 when an
unauthorized test caused
explosions and blasted
radioactive materials into the
air.
• Hundreds of people in the
Ukraine died from radioactive
exposure from this explosion.
• Even today, parts of northern
Europe and the Ukraine
remain contaminated from this
disaster.
•
http://www.cbsnews.com/news/after-30-years-chernobyl-trees-barelydecomposed-study-finds/
The Future of Nuclear Power
• One possible future
energy source is nuclear
fusion.
• Nuclear fusion is the
combination of the nuclei
of small atoms to form a
larger nucleus. Fusion
releases tremendous
amounts of energy.
• It is potentially a safer
energy source than
nuclear fission is because
it creates less dangerous
radioactive byproducts.
Nuclear Power
• Read pg 403-408 and
describe the role that
each part plays in a
Nuclear Power Plant in
your chart.
• On the Back of this paper
in a T-chart compare the
Pros and Cons of Nuclear
Power using pgs 408-412
Fuel
Moderator
Control
System
Heat
Removal
System
Radiation
Shield
Generators: Electricity and
Magnetism
Electricity-Power on Demand
• Because electricity is more convenient to
use, the energy in fuel is often converted
before used.
• Electricity can be transported quickly
across great distances.
• Two disadvantages of electricity are that it
is difficult to store and other energy
sources have to be used to generate it.
How Is Electricity Generated?
• An electric generator is a device that converts
mechanical energy into electrical energy.
• Generators produce electrical energy by moving
an electrically conductive material within a
magnetic field.
• Most commercial electric generators convert the
movement of a turbine into electrical energy. A
turbine is a wheel that changes the force of a
moving gas or a liquid into energy that can do
work.
• The turbine spins a generator to produce
electricity.
How Is Electricity Generated?
•
•
•
•
•
The turbine spins because of the steam released
from boiling water.
The water is heated using a coal-fired or gas-fired
plant, or is heated from the fission of uranium in
nuclear plants.
The turbine spins a loop of wire around a magnet
which induces an electric field.
The electricity is routed through wires and into
homes.
****See handout on Generator
Draw and label this
diagram. Add color!
Power plants in Georgia
http://www.georgiapower.com/about/plants.asp
Videos/segments
• Electricity and Magnetism
• A Segment of: Science Investigations:
Physical Science: Investigating Electricity
and Magnetism The Segment is: Electricity
and Magnetism (9min 15sec)
•Greatest Inventions with Bill Nye: Energy
(55 min)
• http://www.southerncompany.com/learning
power/howplants.aspx
• ***to see animation of plants