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1. Nursyazwani binti Shawal

2. SOURCES OF
ENERGY
Firewood
Fossils fuel
Hydroelectric
energy
Wind energy
Wave energyBiomass energy
Solar energy
Geothermal
energy
Energy from
radioactive
substances
Nursyazwani binti Shawal

3. Hydroelectricity – electricity generated using water
Hydroelectric power – generated by forcing moving
water to produce electricity.
Water flowing from a dam has potential energy.
This energy can be used to rotate turbines and
dynamos to generate electric energy at a hydroelectric
power station.
Water falling from a great height has a lot of potential
energy that can be used to drive turbines that generate
electricity.
Nursyazwani binti Shawal

4. The water turbines turn the generators which then change the
kinetic energy of the moving water into electrical energy.
The water that flows down from the dam contains kinetic
energy that turns the water turbines.
Potential energy is found in water; in a dam, located at a high
position.
Nursyazwani binti Shawal

5. Wind – moving air that contains kinetic energy.
Windmills – for pumping water /grinding grains.
- used for centuries to convert wind energy
into chemical energy; to drive machine.
Wind turbine – uses energy from the wind to generate
electricity.
Wind has kinetic energy that is used to rotate
windmills for the purpose of
a) Grinding wheat
b) Pounding maize
c) Pumping water for the use of animals and irrigation.
Nursyazwani binti Shawal

6. The sea rises and falls twice a day.
Tide – the rising and falling of the sea level
Wave have kinetic energy and potential energy used to
rotate turbines of dynamos in wave-generated power
stations.
Not widely used because the electric energy produced is
not constant but follows the condition of the sea.
The difference in height of the water at high tide and low
tide is used in a tidal power station to generate electricity.
As the tide comes in, water flows through turbines to
generate electricity .
When the tide goes out, water flows in opposite direction.
Nursyazwani binti Shawal

7. Used to describe energy that comes from biological
materials such as animal faeces, plants and
household wastes.
Decaying organic substances produce methane gas.
Ethanol is obtained from fermented plant materials.
Also can be obtained by burning rubbish; producing
heat energy.
Used as fuel for producing heat, working machines
and moving vehicles.
Nursyazwani binti Shawal

8. Energy derived from the Sun.
Heat and light are 2 forms of solar energy.
Solar cells absorb light energy from the Sun directly,
change it into electrical energy.
Solar cells are used to provide electricity for:
a) Calculators b) Satellites
c) Watches d) Certain vehicles
Solar heater – change energy from the Sun into heat
energy which then used for:
a) Heating up water b) Cooking purposes
Nursyazwani binti Shawal

9. Obtained from trunks, branches and twigs of trees.
Most firewood is used in rural area as fuel for cooking.
Produces a lot of soot that pollutes the environment.
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10. Combustible materials – they burns easily to release
heat and light energy.
Supply almost 90% of fuel energy today – most widely
used fuel.
Examples of fossil fuels:
a) Oils (petroleum / crude oil)
b) Natural gas
c) Coal
Most fossil fuels used in power stations to generate
electricity.
Nursyazwani binti Shawal

11. Comes from the very hot interior of the Earth in the form
of heat energy.
Most geothermal areas are near
a) volcanos b) hot spring c) geysers
Geothermal energy can be
a) A tourist attraction
b) A direct source of heating
c) Used as an instant steam-generating facility to spin a
turbine.
Water under the Earth is heated and then pumped out to
a) Heat buildings b) generate electricity
Nursyazwani binti Shawal

12. The steam is channeled into pipes to:
- Heat buildings
- Rotate turbines of dynamos in geothermal power plants
Water that is trapped in the ground is very hot and is in
the form of highly pressurized steam.
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The uses of geothermal energy

13. Radioactive substances like uranium and plutonium
can be used to produce nuclear energy.
Nuclear reactions generate lots of heat energy that can
be used to generate electricity.
Splitting of atoms in radioactive substances release
heat that can be used to produce steam.
Steam turns turbines and dynamos to generate
electricity.
Nursyazwani binti Shawal

14. Energy from radioactive substances can be used to
generate electric energy for
a) Ships
b) Submarines
c) Satellites
d) Meteorological stations
e) Lighthouses
Radioactive wastes are dangerous because they give
out radioactive radiation that is hazardous.
Nursyazwani binti Shawal

15. Sources of energy in the world can be classified into 2
groups:
Renewable energy sources – those that can be
replenished (ditambah) or renewed when they have been
used OR energy sources which cannot be depleted despite
continuous use.
Non-renewable energy sources – those that cannot be
replenished or renewed and will eventually be used up and
exhausted OR energy sources which will be depleted one
day and we will not be able to replace them.
Nursyazwani binti Shawal

16. Sources of Energy
Renewable Non-renewable
•Hydroelectric (moving
water)
•Fossil fuels (coal, petroleum,
natural gas) – not last long
•Wind energy •Radioactive substances
(nuclear energy) – last a long
time
•Wave energy
•Biomass energy
•Solar energy
•Firewood
•Geothermal energy
Nursyazwani binti Shawal

17. Nursyazwani binti Shawal
Hydroelectric energy
Advantages:
 The electricity produced is cheap and does not
pollute the environment.
Disadvantages:
 Dams and power stations are expensive to build.
 Only suitable in mountains areas with good rainfall.
 Large dams destroy habitats.

18. Nursyazwani binti Shawal
Wind energy
Advantages:
 Does not pollute the environment.
 Free
Disadvantages:
 Wind turbines stop working if there is no wind.
 Speed and direction of wind unrelieable
 Many wind turbines are needed to generate the same
amount of energy as one fossil fuel power station.

19. Nursyazwani binti Shawal
Wave energy / Tidal energy
Advantages:
 Does not pollute the environment.
 Occur daily and always present
Disadvantages:
 Only generates electricity twice a day during high
(pasang) and ebb (surut) tides.
 Waves vary in strength
 Expensive to build the power station

20. Nursyazwani binti Shawal
Biomass energy
Advantages:
 Reduce environmental burdens / waste organic matter
 Cheap sources of energy
Disadvantages:
 Releases gases such as carbon dioxide and sulphur
dioxide that pollute the environment.
 Requires a large amount of biomass
 Takes up a large area

21. Nursyazwani binti Shawal
Solar energy
Advantages:
 Can be produced continuously.
 Does not pollute the environment.
Disadvantages:
 Cannot work at night or only operates during the day
while the Sun is shining.
 Expensive to install solar panels
 Depends on whether conditions

22. Nursyazwani binti Shawal
Firewood
Advantages:
 Can be used in areas that lack energy supply for
cooking.
Disadvantages:
 Releases soot which pollutes the environment.

23. Nursyazwani binti Shawal
Geothermal energy
Advantages:
 Does not pollute the environment.
 Plentiful supply of heat
Disadvantages:
 Only available where hot water is located close to the
Earth’s surface.
 Harmful substances present in the steam, e.g. sulphur
dioxide
 Expensive to build a power station

24. Nursyazwani binti Shawal
Fossil fuel
Advantages:
 High energy value / release a lot of energy
 Easy to burn
Disadvantages:
 Produces gases that are poisonous (like sulphur
dioxide) and form acid rain.
 Pollute the environment
 Coal produces a lot of soot

25. Nursyazwani binti Shawal
Radioactive substance
Advantages:
 Very high energy value / supplies plenty of heat
energy
Disadvantages:
 Gives off harmful radiation that can cause cancer.
 Very expensive to build nuclear power stations.
 Danger of accidents
 Suitable radioactive elements not easily obtained

26. Sources of Energy
Pollute the environment Do not pollute the
environment
•Fossil fuels (coal, petroleum,
natural gases)
•Hydroelectric energy
•Radioactive substances
(nuclear energy)
•Wind energy
•Biomass •Wave energy
•Firewood •Solar energy
•Geothermal energy
Nursyazwani binti Shawal

27. Solar cells Solar cells absorb sunlight and convert it
into electrical energy to operate calculators
Solar heaters Solar panels are placed on the roofs of
houses for absorbing heat from the sun.
the heat is used for heating water in hot
water systems
Solar cookers In hot countries, solar cookers concentrate
the Sun’s rays to obtain heat for cooking
Solar power stations Solar panels are used to absorb the Sun’s
heat for boiling water. The steam produced
is used for turning turbines which drive
generators for producing electricity
Nursyazwani binti Shawal

28. Telephone in rural areas Some rural areas are installed
with telephones which are
operated by solar cells
Satellites Solar panels on satellites absorb
sunlight and change it into
electrical energy for operating the
satellites
Photosynthesis Green plants absorb light energy
from the sun and use it to make
food by photosynthesis. In this way,
solar light energy is converted into
chemical energy
Nursyazwani binti Shawal

29. To save non-renewable sources of energy such as fossil
fuels (oil, gas, coal) from depletion as the supply is
limited; but widely used all over the world.
To reduce the amount of money spent on electricity,
gasoline (minyak petrol) and other forms of energy.
To protect our high standard of living which is due (in
part) to our abundant energy sources.
To reduce the ‘side effects’ of energy use: pollution,
damage to animal habitats and ruined landscapes.
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30. More efficient equipment must be invented so that
energy can be used more economically.
Develop the use of renewable energy sources to replace
non-renewable energy sources.
Use non-renewable energy sources in an economical,
efficient and smart way.
New fuels such as diesel and palm oil, and other
renewable energy sources like hydroelectric energy,
biomass energy, wind energy and wave energy should
be widely used as alternative energies.
Nursyazwani binti Shawal

31. Since the Earth has limited amounts of non-renewable
energy sources like fossil fuels, they must be conserved
in order to avoid:
 Future energy crisis due to shortages or overuse of
fossil fuels.
 A growing exploitation of natural resources.
 Atmospheric contamination that causes global
warming and climatic changes, acid rain and smog.
The resulting impact damages water sources e.g.
groundwater, soil, crops, wildlife and wildlife
habitats, building materials and human health.
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32. Recycle material
Develop more efficient engines that use less energy
to operate.
Put emphasis (penegasan/penekanan) on the use
of renewable energy sources such as solar energy.
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