The
discovery
of
electricity
What is the Greenhouse
Effect?
The earth’s atmosphere has several gases which
together act like a blanket to keep the earth at a
comfortable temperature. If these gases were not
there, the earth would be much colder, probably by
about 30 degrees Celsius.
Greenhouse gases causing the most problems
for our environment are carbon dioxide, methane,
chlorofluoro-carbons, halons, tropospheric ozone
and nitrous oxide.
Because of a fast-growing world population and
its need for more energy-consuming appliances,
more cleared land and transport, these gases are
increasing in the atmosphere.
1
The discovery of electricity fact
sheets reviewed and updated with
the assistance of STAV Publishing
Scientists around the world are concerned that
this increase could warm the earth and change
our climate. In Victoria, the changes could mean a
warming of temperatures by two to four degrees
Celsius by the year 2030, causing a rise of up to
30 centimetres in sea levels, heavier rainfall, more flash
flooding, increased wind speed and more bushfires.
These changes could happen gradually unless we
find ways of slowing down the greenhouse effect
by controlling the amount of gases released to the
atmosphere.
print
friendly
What causes the greenhouse effect?
Put simply, humans cause it. How?
• By burning fossil fuels such as brown coal, black coal, gas and oil
in power stations, industry and transport. The burning of fossil fuels
releases carbon dioxide and causes about half of the greenhouse effect.
• By cutting down too many trees. More trees are needed because they
absorb carbon dioxide.
• By using aerosol sprays and refrigeration systems which release
chlorofluorocarbons and halons. These two gases also damage the
upper ozone layer, causing the <ozone hole> that appears each spring
over Antarctica.
• By the growing of rice, farming of animals, and leakages from natural
gas pipes, all of which release methane.
Other
20%
6%
4%
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friendly
Carbon Dioxide CO2
Nitrous Oxide N2O
2
Methane CH4
Annual contribution
of major greenhouse
gases
70%
What is being done about it?
Reducing carbon dioxide discharges isn’t easy, but here are a
few possible solutions.
<How much coal
does it take to run a
light-globe? Activity>
Solution 1: Conserving energy
Energy conservation is the best way to cut down our carbon
dioxide releases.
In the home, it often requires little effort. Just a few examples:
Use cold water to wash your clothes. Using a cold setting will save
3 kilograms of greenhouse gas per wash (compared to a hot wash).
3
When you’ve finished watching a video or TV or listening to a CD,
switch the unit off completely (preferably at the wall). You’ll save
anywhere between 20 and 85 kg of greenhouse gas by doing this.
Likewise, when you’ve finished with your computer for the day turn
it completely off.
Shorter showers and fixing dripping hot taps are also great ways to
save energy and water.
Buying more energy efficient appliances and <light globes>
print
friendly
Solution 2: Electricity from waste
• Rubbish tips
Decaying food scraps discharge a lot of methane, which, molecule
for molecule, is many times more damaging to the atmosphere than
carbon dioxide.
Methane is used as a fuel for small power stations built on top of
rubbish tips.
Embracing methane power technology means less brown coal is
burned and local councils not be discharging methane.
Embracing methane power technology would mean less brown
coal would be burned and local councils would not be discharging
methane.
4
• Co-generation
Co-generation is when heat and power are produced and used at
the same time from the same energy source. The heat, which in the
past usually went to waste, is either a by-product of a manufacturing
process or a by-product of the burning of a fuel like gas to produce
electricity. An example of the latter is a car manufacturer with a gasfired turbine producing electricity for its manufacturing equipment
and, at the same time, using the heat from the gas turbine exhaust
to dry painted cars.
With the combined use of heat and power, industries can cut their
total energy use by more than 50 per cent.
print
friendly
Solution 3: Other less harmful fuels
• <Wind>, <water> and <solar>
More electricity will gradually come from fuels that are renewable,
especially wind, water and the sun.
At the moment, the equipment to use these fuels costs much more
than equipment for brown coal power stations. All of us have to
decide if we are prepared to pay these costs.
Of the renewable fuels, wind shows the most promise for Victoria.
Activity
Research some of the arguments for and against wind
turbines.
• Gas
Gas-fired power stations release half as much carbon dioxide
as brown coal stations of the same generating size. We have to
remember, though, that our use of gas is limited as it is not available
in the same large quantities as brown coal.
5
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friendly
6
CitiPower and Powercor
sponsor Landcare days.
Solution 4: <Planting trees>
<What’s the real
story? Activity >
Trees (especially the fast-growing types) absorb and store carbon
dioxide from the atmosphere.
Victoria’s supply industry plants thousands of trees on its many
hectares of land throughout Victoria. It is also helping with community
tree planting programs.
About 350 healthy, fast growing trees are needed to balance the
carbon dioxide released in the production of electricity for just one
Victorian household.
More information
Reducing emissions and planting trees
<http://www.greenfleet.com.au/>
Greenhouse
<http://www.cmar.csiro.au/e-print/open/gh_faq.htm>
<http://www.greenhouse.gov.au/science/faq/page5.html>
<http://www.abc.net.au/science/planetslayer/greenhouse_
qa_greenhouse.htm>
<http://das.ee.unsw.edu.au/~solar/classrooms/1_1.html>
<http://www.acfonline.org.au/uploads/res_climate_
cutting_pollution.pdf>
Ozone hole
<http://www.bom.gov.au/climate/
glossary/ozone.shtml>
print
friendly
How much coal does it take
to run a light-globe? Activity
Approximately 1.39 kg of greenhouse gas emissions (including
carbon dioxide, nitrous oxide and sulphur dioxide) is produced for
every kilowatt hour (kWh) of electricity produced from coal.
The first challenge!
Calculate how much brown coal (lignite) is required to power one standard
100 W light globe in your house for one year, and then calculate how much
greenhouse gas this amount of coal produces! Assume the light-globe will
be on 24 hours a day for one year.
Information you will need to solve the problem:
• 1 kWh = 1 kilowatt of power for one hour
• 1 kg of lignite produces 11.3 MJ of energy.
• 1 megajoule (MJ) = 0.2777778 kilowatt hour
• The efficiency of the best coal-power stations is approximately 40%
If you get stuck, have a look at the following websites.
• Origin Energy: A greenhouse calculator can be found at the environment
section on this site: http://www.originenergy.com.au/
• How Stuff Works: This site is American, so you will need to convert all
the units into metric measurements: http://science.howstuffworks.com/
science-channel.htm
Next step
Now you know how much coal is needed to power just one light globe in
your house, have a look at some of the other appliances you use everyday
and calculate how much coal they require.
Here are some suggestions:
7
Appliance
Power usage (W)
Toaster
820 W
Clock radio
13 W
Computer screen
40 W
If you changed all your light globes to energy saver, low wattage globes,
how much less green house gas would your house produce?
What’s the real story? Activity
Around the world, energy companies, governments, scientific
institutions and individuals are looking at the consequences
of an enhanced greenhouse effect.
Working in groups, choose one of the topics below and find out as much as
you can about it. Hold a class conference, where every group presents their
findings as a poster, “scientific style” paper or multimedia presentation.
Topics
1. The majority of Australia’s electricity comes from coal, despite it
being the cause of so much greenhouse pollution.
8
Choose one of the topics below:
a. Find out how coal is formed, and what types of coal are used by
Australian industries.
b. Research the alternatives to coal power in Australia, and decide
whether these alternatives are suitable in all circumstances.
c. Find out about three current, Australian scientific studies being
undertaken into coal and what they have found out so far.
2. Australia has received extensive criticism from the world community
by refusing to sign the Kyoto Protocol.
a. What is the Kyoto Protocol and who has and who hasn’t signed it?
b. What might the Protocol mean for Australia?
c. What reasons has Australia given for not signing the Protocol?
d. Do you think the Protocol will work to reduce the effect of
greenhouse gases on the environment? Why or why not?
3. What can the average Australian do to reduce the amount of
greenhouse gases they produce? Will these measures make a real
difference – why or why not? What are some of the problems involved
with trying to make a difference at the local level?
Suggestions
• Your group might like to design a survey to find out people’s attitudes towards the Greenhouse Effect.
• Your group could contact some of the organizations working on solutions for the enhanced greenhouse
effect, and ask for information to be sent to you. You could include this information in your
presentation.
• You could write to your local member of parliament, asking about the Government position on the
Greenhouse Effect and the Kyoto Protocol.
What is the Greenhouse
The earth’s atmosphere has several
gases which together act like a
blanket to keep the earth at a
comfortable temperature. If these
gases were not there, the earth would
be much colder, probably by about
30 degrees Celsius.
Greenhouse gases causing the
most problems for our environment
are carbon dioxide, methane,
chlorofluoro-carbons, halons,
tropospheric ozone and nitrous oxide.
Because of a fast-growing world
population and its need for more
energy-consuming appliances, more
cleared land and transport, these
gases are increasing in the atmosphere.
Scientists around the world are
concerned that this increase could
warm the earth and change our climate.
In Victoria, the changes could mean
a warming of temperatures by two to
four degrees Celsius by the year 2030,
causing a rise of up to 30 centimetres
in sea levels, heavier rainfall, more flash
flooding, increased wind speed and
more bushfires.
• By using aerosol sprays and
refrigeration systems which release
chlorofluorocarbons and halons. These
two gases also damage the upper ozone
layer, causing the <ozone hole> that
appears each spring over Antarctica.
What is being done about it?
• Co-generation
Reducing carbon dioxide discharges
isn’t easy, but here are a few possible
solutions.
Solution 1: Conserving energy
Energy conservation is the best way to cut
down our carbon dioxide releases.
In the home, it often requires little effort.
Just a few examples:
Use cold water to wash your clothes.
Using a cold setting will save
3 kilograms of greenhouse gas per wash
(compared to a hot wash).
What causes the
greenhouse effect?
Shorter showers and fixing dripping hot
taps are also great ways to save energy and
water.
• By cutting down too many trees. More
trees are needed because they absorb
carbon dioxide.
Embracing methane power technology
means less brown coal is burned and local
councils not be discharging methane.
Embracing methane power technology
would mean less brown coal would be
burned and local councils would not be
discharging methane.
These changes could happen gradually
unless we find ways of slowing down
the greenhouse effect by controlling
the amount of gases released to the
atmosphere.
• By burning fossil fuels such as brown
coal, black coal, gas and oil in power
stations, industry and transport. The
burning of fossil fuels releases carbon
dioxide and causes about half of the
greenhouse effect.
Methane is used as a fuel for small power
stations built on top of rubbish tips.
• By the growing of rice, farming of
animals, and leakages from natural gas
pipes, all of which release methane.
When you’ve finished watching a video or
TV or listening to a CD, switch the unit off
completely (preferably at the wall). You’ll
save anywhere between 20 and 85 kg of
greenhouse gas by doing this. Likewise,
when you’ve finished with your computer for
the day turn it completely off.
Put simply, humans cause it. How?
Effect?
Co-generation is when heat and power are
produced and used at the same time from
the same energy source. The heat, which
in the past usually went to waste, is either
a by-product of a manufacturing process
or a by-product of the burning of a fuel
like gas to produce electricity. An example
of the latter is a car manufacturer with a
gas-fired turbine producing electricity for its
manufacturing equipment and, at the same
time, using the heat from the gas turbine
exhaust to dry painted cars.
With the combined use of heat and power,
industries can cut their total energy use by
more than 50 per cent.
Solution 3: Other less harmful fuels
• <Wind>, <water> and <solar>
More electricity will gradually come from
fuels that are renewable, especially wind,
water and the sun.
Buying more energy efficient appliances and
<light globes>
At the moment, the equipment to use these
fuels costs much more than equipment for
brown coal power stations. All of us have
to decide if we are prepared to pay these
costs.
Solution 2: Electricity from waste
Of the renewable fuels, wind shows the
most promise for Victoria.
• Rubbish tips
Decaying food scraps discharge a lot of
methane, which, molecule for molecule,
is many times more damaging to the
atmosphere than carbon dioxide.
The discovery of electricity fact
sheets reviewed and updated with
the assistance of STAV Publishing
Activity
Research some of the arguments for
and against wind turbines.
• Gas
Gas-fired power stations release half as
much carbon dioxide as brown coal stations
of the same generating size. We have to
remember, though, that our use of gas is
limited as it is not available in the same large
quantities as brown coal.
Solution 4: <Planting trees>
Trees (especially the fast-growing types)
absorb and store carbon dioxide from the
atmosphere.
Victoria’s supply industry plants thousands
of trees on its many hectares of land
throughout Victoria. It is also helping with
community tree planting programs.
About 350 healthy, fast growing trees are
needed to balance the carbon dioxide
released in the production of electricity for
just one Victorian household.
More information
Reducing emissions and planting trees
<http://www.greenfleet.com.au/>
Greenhouse
<http://www.cmar.csiro.au/e-print/open/
gh_faq.htm>
<http://www.greenhouse.gov.au/science/
faq/page5.html>
<http://www.abc.net.au/science/
planetslayer/greenhouse_qa_greenhouse.
htm>
<http://das.ee.unsw.edu.au/~solar/
classrooms/1_1.html>
<http://www.acfonline.org.au/uploads/res_
climate_cutting_pollution.pdf>
Ozone hole
<http://www.bom.gov.au/climate/
glossary/ozone.shtml>