Turn It On!–Atlantic Teacher's Guide
9
Lesson
Activate
Content Background
Student Book pages 30–33
In this lesson: Students explore how power
plants generate electricity and compare
different types of power plants.
Outcomes
Students will have opportunities to:
• identify and investigate various methods of
generating electricity (past, present and
future), and describe some ways in which
these methods affect the environment
(303-28, 105-3, 108-8)
• identify and explain sources of electricity as
renewable or nonrenewable (303-29)
• identify and explain different factors that
could lead to a decrease in electrical energy
consumption in the home and at school and
how will this help protect the environment
(108-5, 303-30)
Assessment
• Note how students modify their sources of
electricity charts after completing the
Exploration. Ask them to justify any
additions or changes that they make.
(303-28, 105-3, 108-8, 303-29)
• Assess students’ arguments as they debate the
best way to generate electricity in
Communicate your results. Do they take a
number of factors into consideration—
environmental concerns, cost, availability,
reliability, and so on? (303-28, 105-3, 108-8,
303-29)
• Ask students to name three sources of power
that are considered clean. Why are they
considered clean? (Sun, wind, and water are
considered clean because they produce no waste
products.) Are these sources renewable or
non-renewable? (renewable) (303-28, 105-3,
108-8, 303-29)
• Ask students to revisit their energy reduction
plans from Lesson 2. What changes or
additions would they like to make, based on
what they learned in this lesson? (303-28,
105-3, 108-8, 108-5, 303-30)
Getting Organized
Time Required: Activate 10
minutes; Explore 20-30 minutes,
plus time for research; Apply
10-15 minutes
Advance Preparation: You may want to bring
in an electric fan and a pinwheel for use in
your discussion.
Lesson Vocabulary
turbine: the part of a generator that uses the
motion of water, steam, or wind to turn the
coils or magnets in the generator.
hydroelectric power: electricity produced by
water turning the turbine of a generator.
Canada’s Ballard Fuel Systems is
the leading developer of fuel cells,
the energy of the future. Fuel cells
directly convert hydrogen into
electricity without combustion, and
can continuously produce electricity
as long as they are supplied with
enough hydrogen and oxygen.
T
he electric power provided by utility
companies is produced in essentially the
same way that Englishman Michael
Faraday produced the first weak current
with a small coil of wire and a bar magnet
in 1831. Power plants use banks of massive
generators to spin huge coils of wire through
the magnetic fields of extremely powerful
electromagnets. Power plants almost always
use alternating-current generators, which
produce electric currents that move back
and forth many times a second.
Because energy can’t be created or
destroyed, only transformed from one kind
of energy to another, producing electric
energy really means transforming another
form of energy into electric energy. The
production of electricity depends on
mechanical energy to move the wires or
magnets. Large generators use the
mechanical action of fanlike turbines to
spin their coils of wire. In turn, the turbines
are rotated using the fall of water or, most
commonly, the push of steam. Heat to
produce the steam comes mainly from
burning fossil fuels and sometimes from the
breakdown of nuclear materials in nuclear
reactors. The push of wind and tides can
also spin turbines, and these natural power
sources are being used and examined more
as environmental awareness grows.
Researchers are also experimenting with
other natural heat sources, such as solar
energy and thermal energy.
Two useful resources are:
Energy Factsheets
www.iclei.org/efacts/content.htm
The Energy Use and Resources module
from B.C. Hydro’s educational site
http://eww.bchydro.bc.ca/education
/4-7/4-7_mod1a.html
Review Making Electric Current
Review with students what they learned about
generating electric current in Lesson 8. Ask:
Where do you think the electric current we
use in school and in our homes comes from?
(Most students will probably say from a power
plant.)
How does the current from the power plant
get to your school? (Students will probably be
familiar with wires on utility poles and
transmission line towers.)
Ask students to identify places where they’ve
seen such wires.
After reading the opening paragraph on
page 30, ask: Can you think of any methods
for producing large amounts of electricity?
Write students’ responses on the board.
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Lesson 9: How Do Power Plants Use Magnets To Generate Electricity?
Lesson 9: How Do Power Plants Use Magnets To Generate Electricity?
Explore
How Do Power Plants Use
Magnets to Generate Electricity?
After students have read the first two
paragraphs, display a pinwheel or an electric
fan. Ask:
How can you put a pinwheel in motion?
(You can blow on it, move it with your hand, or
let the wind push it.) How would you put the
fan into motion? (You would spin its blades.)
Can a fan move another object? How? (Yes;
when the fan is in motion, it can push wind on
an object and move it.)
Have students consider the steam that rises
from a pot of boiling water. Ask them to think
about whether the steam could be used to
move the blades of the fan. Include the idea of
water and wind as elements that might move
the blades. Help students see that steam, water,
or wind (in large enough quantities and with
enough pressure) could certainly move the
blades of the fan.
Ask students to read the rest of the section
and examine the diagram and photos. Ask:
Which part of the turbine in the diagram
produces motion? (The propeller and the rod
on which it rests.)
Which methods for generating electricity
seem the most dangerous to our
environment? (Answers will vary. Have
students explain why burning fossil fuels or
nuclear waste seems more dangerous to them.)
Which methods for producing electric
energy seem safe? (Students will probably say
solar energy and the energy from the wind.)
Why aren’t windmills and solar disks used
everywhere and all the time? (Help students
realize that the amount of sun and wind
received in any given area isn’t consistent.)
How can the wind be used to generate
electric energy? (The wind can turn a turbine
that drives a generator.)
Can you think of any other ways to
generate electric energy that haven’t been
mentioned? (Answers will vary. Encourage
students to think of ways that may help recycle
or conserve natural resources.)
• Coal, oil, uranium or plutonium (for nuclear
plants), and gas are non-renewable energy
sources. Sun, water, and wind are renewable
sources.
• Hydroelectric energy is the most efficient and
reliable way of producing electricity in
Canada, but it also floods large areas of land.
The least harmful to the environment are
wind and solar energy.
Have students make a chart to grade the
different sources of electricity. Before they start
their chart, ask them to discuss what criteria
they should use to grade the different source.
Ask them to evaluate their charts after they
have completed the Exploration on page 32.
What new information did they learn. Would
they change any grades?
Global Perspectives
Nikola Tesla, a Serbian-American inventor who
immigrated to the United States as a young
man, designed and built the first hydroelectric
power plant at Niagara Falls, New York. While
previous direct-current power plants could
transmit electric current up to a mile away,
Tesla’s alternating current power plant could
send power 35 km away to Buffalo. Tesla also
invented the AC induction motor, which was
the first electric motor to run on the alternating
current we use today.
Information Connection
(Student Book page 31)
Sources of electricity
In Canada, hydroelectric power is used the
most. Help students understand that because of
the abundance of water in Canada,
hydroelectric power is the best and most
efficient source of electric power we have. Ask:
What are some ways that people can
conserve energy? (Possible answers may
include using public transportation or regulating
the temperature in private homes.)
Which source of power does Canada use
much less of than the rest of the world?
(fossil fuels)
Display a world map and relate the land area
of Canada to other nations in the world. Tell
students that Canada is the second largest
country in land area, though its population is
just under 30 million. Although 66% of
electricity in Canada is from hydroelectric
power, 13% is from nuclear power and 21%
from fossil fuels, mainly coal, oil, and natural
gas.
• People use the most electricity in the winter
because of the constant need for heating. Air
conditioners drive up electricity use in the
summer, but are not used all the time, only
during heat waves.
Helping ESL Learners
Write the words fossil fuels, uranium, sun,
wind, and water on the board and explain to
students that these are all examples of natural
resources. Explain to students that natural
resources are used to generate electrical energy,
then have them look at the photographs in this
lesson without reading the captions. Ask them
to try to match the natural resource that would
be used for each power plant in the
photograph.
Why do you think Canada consumes so
much fossil-fuel power? (Answers will vary.
Students will probably suggest that cars, modern
technology, and numerous industries consume a
lot of fossil fuels.)
• Students may say that most electricity use is
around 6 p.m., because that’s when most
people are cooking dinner and using a lot of
water and different appliances: stoves,
blenders, microwaves. Ask students to go
back to their Energy Reduction Plans from
Lesson 2. Would they like to change or add
anything to their plan? Had they considered
the time of day?
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Lesson 9: How Do Power Plants Use Magnets To Generate Electricity?
Lesson 9: How Do Power Plants Use Magnets To Generate Electricity?
E x p l o re
Apply
Preparing for the Exploration
Closer to Home
Suggested Grouping: individual or pairs
(Student Book page 33)
Integrating Science
Materials per Group: research materials such
as books and Internet access
Power, pollution, and the planet
Social Studies: Reading Meters
Have students make a diagram of an electric
meter, which they can fill in at home. Draw
three large circles in a row on the board and
have students copy them twice on a sheet of
paper. The top row will be for the school’s
electric meter, and the bottom row will be
for the meter where they live. Tell students
to write the date under each meter. Show
them how to number the dials alternatively
clockwise and counter-clockwise. Explain
that each dial measures the flow of
electricity in amounts called kilowatt hours.
Over each dial, students can write the
amounts—starting at the right, 1’s, then
10’s, then 100’s. You might also mention
that the electric company charges its
customers about one tenth of a penny for
every kilowatt hour of electricity used. Take
students to look at the school’s electric
meter, or take down the reading ahead of
time. Students can record the electric meter
reading in their homes on the bottom row of
circles. Record new readings in a week and
compare them.
Approximate Time: 2-3 days to research and
write their chart
(Student Book page 32)
Research sources of energy.
1-2. Once students select the source of energy
they are going to research, they should
decide where the best place to find
information would be—books, the
Internet, a utility company, and so on.
3. Students should base their charts on the
factors discussed on page 30. In small
groups or as a whole group, discuss the
information the students researched. How
does this information change their view of
certain sources of energy?
Interpret your results.
• Answers will vary for all three points. Ask
each group the questions orally or have
students write the answers in their Science
Journals.
• Student should say that they will be more
aware of how much electricity they use and
try to keep it to a minimum.
To help students understand that we pay an
environmental price whenever we use energy
sources, encourage them to consider how using
natural resources affects the environment. Ask:
When people dam a lake or river or drill for
oil in the ocean, what happens to the
animals that live in the water or nearby?
(They lose their food supplies and their homes.
Many animals are forced to move; others are
unable to do so and eventually die.)
What happened to the plants and animals
that used to live above the mines where
people dig for fossil fuels and uranium?
(They lost their food sources and habitats, too.)
Can you think of ways to build power
plants that wouldn’t endanger the
environment?
• Building banks of wind generators and solar
collectors could reduce air pollution, but
might also disturb the land where plants,
animals, and people live.
• Building high-voltage power lines disturbs the
habitats of plants and animals.
• The Ballard Fuel Cell is the cleanest method
developed so far for producing electricity
because the only residue it leaves is water—
there is no exhaust or air pollution when it is
used in cars and buses.
Language Arts: Let’s Go Solar
Have students write a short article that will
persuade people to use solar energy.
Encourage them to think of a good title.
Point out that there are two basic ways that
solar energy can be changed to electricity.
One way is to use large solar electric cells.
The cells are arranged in open fields where
sunlight is plentiful. The second way is to
heat water with sunlight to make steam.
Have students research these methods for
their article. You may want students to get
on-line to share their information.
Art: How the Turbine Turns
Have students choose one resource used to
produce electricity. Then ask them to draw a
diagram showing how that resource can turn
the turbine of a generator in a power plant.
Have students use arrows to indicate the
direction of movements. Tell them to use
captions to describe how the turbine is being
turned.
Communicate your results.
• Students can debate which source or sources
of electricity are the best for Canada or your
area. Remind them to consider all the factors.
Most of the electricity is produced
in Canada by hydroelectric power.
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Lesson 9: How Do Power Plants Use Magnets To Generate Electricity?
Lesson 9: How Do Power Plants Use Magnets To Generate Electricity?