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Activity Sheet 1
Electricity: An Introduction
Key words and definitions for you to know
Electricity - A form of electricity from the movement of electrons from one
element to another producing a charge.
Fossil fuels- A hydrocarbon deposit, such as petroleum, coal, or natural gas, derived from
living matter of a previous geologic time and used for fuel.
Grid - The power highways for electricity, including substations and large power lines.
Kinetic energy- The kinetic energy of an object is the energy which it possesses due to its
motion.
Non- renewable resource- a natural resource which cannot be produced, grown,
generated, or used on a scale which can sustain its consumption rate, once used there is
no more remaining.
Potential energy- The energy stored in a body or in a system due to its position in a force
field or due to its configuration.
Transmission-the bulk transfer of electrical energy, from generating power plants to
substations located near population centers via powerlines.
Like to surf? Learn more about this topic at…….
Wikipedia- electricity generation definition
http://en.wikipedia.org/wiki/Electricity_generation
Eskom: How is electricity generated
http://www.eskom.co.za/live/content.php?Item_ID=5625
How is electricity transmitted
http://www.eskom.co.za/live/content.php?Item_ID=5606
How is electricity distributed
http://www.eskom.co.za/live/content.php?Item_ID=5607
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ACTIVITY 1A: COAL FIRED ELECTRICTY GENERATION
Activity Instructions:
1. Listen to the ‘Electricity Facts ’ introduction from your educator.
2. Look at the picture below that shows how electricity is made from
burning coal and then read the paragraph below it…...
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Figure 3: The process of making electricity from coal.
Making Electricity from Coal:
1. Coal is mined from the ground and taken to the power station. It is broken down
into a powder.
2. This powdered coal is fed into a boiler and burned at around 1400ºC.
3. Surrounding the walls of this boiler are pipes filled with water.
4. The heat turns this water into steam. This steam passes through a turbine (like a
large fan). The steam causes the turbine to spin very fast. This creates a magnet
effect.
5. This pushes an electric current through wire coils and out of the power station
through power lines.
6. These lines bring the electricity to our houses and other buildings via transmission.
(Source: http://www.uky.edu/KGS/coal)
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This is a popular and somewhat effective way of producing electricity but causes pollution
of the environment as noxious gasses and carbon is emitted into the atmosphere.
It causes serious environmental pollution problems which affect people’s health and well
being. Mercury, sulphur and toxic sludge are the waste products of this process. Carbon
dioxide produced from these power stations is also causing climate change which is
negatively affecting weather patterns, food production, people and animals. Coal is also a
non-renewable source which means that once it has been used up there is no more left to
power these stations.
Saving electricity will help us reduce the pollution and the impact on people and the
environment.
Do you know that almost all of our electricity is generated in Mpumalanga- some 2000 km
away in the North of South Africa? We used to have a coal fired power station in Athlone
here in Cape Town. It is not used anymore but the health effects of this power station are
still a problem for many people who worked at the power station or lived near-by. Some of
our electricity is also created at the Koeberg power station. This is a nuclear power station
and creates electricity by splitting atoms in a nuclear reactor. This unfortunately creates
nuclear waste which is very poisonous.
Group Work:
In groups discuss the following questions:
• What do you think the alternatives to coal fired electricity production
are? Think about other ways electricity is made.
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Do you think we could have a future without coal fired electricity production?
Take it Home:
• Search for and read newspaper, magazine and internet articles on the
health and environmental problem associated with coal fired power stations,
and cut them out.
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Ask your parents, grandparents or someone you know if they remember the Athlone
power station.
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ACTIVITY 1B: FUTURE ELECTRICITY USE
Activity Instructions:
1. Listen to the ‘Electricity Facts’ introduction from your educator.
2. World electricity use is expected to increase by 71 percent from 2003 to 2030. Fossil
fuels (such as coal and oil) still supply a lot of the electricity used around the world.
The biggest growth will be in developing countries such as India, Brazil and South
Africa. Look carefully at the picture below. This is a bar graph. It shows past and
future (predicted) world electricity use between the years 2007 to 2035.
Figure 4: Future world electricity use scenario
Exercise:
Answer the questions provided.
Look at the graph above, see that the bottom of the bar graph shows the year. (For future
grades: This is called the ‘x axis’). And that the left hand side of the graph shows the amount
of electricity used in units. (For future grades: This is called the ‘y axis’). Pretend that 1 unit –
1 Terawatthour ( 1 trillion watthours) Do you note that electricity consumption is going up as
the years progress?
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Questions:
1. What is the next number in this sequence: 2020; 2025; 2030; ________
2. How much electricity is expected to be used in the year 2020? _____
3. How much more electricity is used in the year 2035 than will be used in the year
2020? (Clue: Use subtraction skills). _____
4. If 100 more units of electricity were added to the year 2035’s electricity use, how
much electricity would be used in that year? _____________
5. What would happen if the population in 2020 halved and what would the electricity
use be? ( Clue: divide the amount of electricity to be used in the year 2020 by 2) ___
6. If the amount of electricity used in year 2020 was to be 600 and the amount of
electricity increased by 100 every 5 years, what would the amount of electricity used
be in 2040? (Do not look at the bar graph to answer this question. It is an
independent word problem) _________
Group Work:
In your groups discuss the following questions:
• Why is future electricity use expected to be so high (tip: think about
development, population sizes, etc.)?
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Do you think that the world can handle this much electricity use and what do think
would happen to the world if we were to use so much electricity in the future?
Take it Home:
• Tell your parents, relatives and community about what you have learnt
about the future of electricity use during this Activity.
Did you know?
Hot water accounts for almost 40% of your electricity bill. You can
safely turn your geyser temperature down to 60°C and save up to
5% on your electricity bill.
Activity Sheet