WEEK 1
Rocks and minerals and their exploitation
Formation of rocks
Rock is the solid and naturally occurring material that forms the earth’s hard
outer layer or crust.
Rocks come in variety of shapes, size color, texture, weight, consistency,
permeability and hardness.
Almost all rocks are composed of an aggregate of grains of different
chemical elements called minerals.
Classification of rocks
https://www.youtube.com/watch?v=CeuYx-AbZdo
They are classified according to how they are formed.
1. Igneous rocks
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Are rocks created from the solidification of magma (Molten rock found in the
mantle below the earth’s crust) and lava (molten rock that reaches the
surface through a volcano or fissure).
Types of igneous rocks
There are two types:
a. Plutonic or intrusive rocks
They occur when magma cools and crystallises slowly within the earth crust
e.g. Granite.
b. Volcanic or extrusive rocks
Are formed when the lava solidifies on the Earth’s surface e.g. Basalt.
2. Sedimentary rocks
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Sediment refers to the particles of rocks, minerals and the remains of
plants and animals.
Weathering: rocks are continuously being broken down into smaller
pieces or sediments by the physical and chemical processes.
The freeze- thaw action of water is a chemical process that widens
cracks and causes the rock to eventually break apart.
Sediments are then transported to the seas, rivers and oceans by
forces of erosion where they are deposited. They mix up with loose
sediments of mud, silt, sand, gravel and skeletons of sea creatures
and can build up into thick layers.
As new layers of sediments are added above, lower layers are
compressed over millions of years into strata of hard rock through a
process called cementation.
Examples of sedimentary rocks
Limestone
Sandstone
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Shale
3. Metamorphic rock
When the Earth’s movements cause existing igneous and sedimentary
rocks to be heated and put under pressure, a chemical change in their
minerals occur leading to formation of new metamorphosed rocks.
Examples of metamorphic rocks:
a. Slate which is formed from shale
b. Marble which is formed from limestone
Marble
Slate
Table summarizing characteristics of different rock types
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The rock cycle
https://www.youtube.com/watch?v=G7xFfezsJ1s
Questions
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Extraction of rocks and minerals from the earth
Minerals provide us with a wide range of materials that we use in everyday
life for example:
a) Coal and oil provide energy and many chemicals used in industry
b) Metallic ores provide us with the metals and alloys needed to make
products such as computers, mobile phones, cars, wires and nails. The
demand for minerals continues to increase, both from developed and
developing countries.
Before rocks are extracted, searching has to be done to ascertain their
location on the earth’s surface.
Searching for minerals
There are two ways for searching for minerals:
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1. Prospecting: is the simplest way to find mineral deposits. This is
done by looking carefully at the surface of rocks. This method has
found nearly all the surface deposits of minerals worldwide.
2. Remote sensing methods: An area of land can be photographed
from the air and the images carefully analyzed for signs of minerals.
Aerial photography can cover much more ground than a person
walking over the surface of rocks.
Mineral deposits are weathered at the earth’s surface, producing
mineral oxides which can be detected by their unique radiation
pattern, which is recorded by a satellite and downloaded to a computer
for analysis.
The satellite’s positioning system records the exact location of
minerals and the geologists visit the location to confirm the minerals
that have been identified correctly. Two ways to identify the minerals
present in a rock are:
(i)
Geochemical analysis: Samples are taken to the laboratory
so that the chemicals in the samples are identified.
(ii)
Geophysical analysis: A series of vibrations (seismic
waves) are sent through the earth’s surface. Several sensors
at different distances from the source of vibrations are laid
on the ground. The vibrations create shock waves that travel
down into the rock layers and are reflected back to the
sensors on the surface. The shock waves record different
patterns depending on what minerals are present in rock
layers.
Methods of extracting rocks:
There are two main methods extracting rocks containing minerals from the
earth’s crust:
1. Surface mining/opencast, open-pit, open-cut or strip mining
 Only used when the ore (rock containing the mineral) are found relatively
close to the surface and the surrounding area is not heavily built up.
 The overburden (soil and rock) overlying the ore body is first removed by
special earth-moving machinery.
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 Once the ore is exposed, other equipment such as massive dragline and
bucket wheel excavators dig out and remove the ore from flat terraces or
benches that circle the mine at descending levels.
2. Subsurface mining
This removes minerals through underground mining methods such as
declines, vertical or inclined shafts and tunnels and adits.
The overlying rocks remain in place.
Declines are wide tunnels that descend in a circular manner down to and
around the ore body.
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The ore is hauled to the surface in huge trucks.
Tunnels are sunk down adjacent to the ore body when ore body is too deep
to be reached by inclines which are then removed by lifts.
Underground mining methods versus surface mining methods
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Types of mining
1. Surface mining.
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2. Subsurface mining
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WEEK 2
Factors affecting the mining of rocks and minerals
a. The costs of exploration and extraction:
▪ the process of exploration (mineral Greenfield) is done by a company
to determine the presence of ore bodies underground.
▪ there are fewer technical difficulties of mining on a large scale using
open-pit mining as there would be low extraction costs per tonne.
▪ Shaft mining is costlier to set up and maintain as the cost per tonne
will be higher. So, only deposits of higher value can be mined in this
way.
b. Geology:
▪ High-grade ores yield more of the required chemical elements than
low-grade ores.
▪ Small deposits of high-grade ore are worth mining.
▪ Small deposits of low-grade ore that cannot be mined at a profit are
left as reserves.
c. Accessibility:
▪ transporting the ore from the mine to processing plants can be
difficult and expensive.
▪ the cost of building road or rail links to the processing plant or to the
nearest port for export has to be considered.
▪ carrying out some processing at the mine reduces transport costs.
▪ the mining company must be given a license before extracting a
deposit.
▪ a long-term agreement between the government and mining
company must be reached to avoid rapid rises in the tax, which makes
the mining unprofitable.
d. Environmental Impact Assessment:
▪ for a license application to be approved, the company must have a
plan to keep the loss of habitat minimal, followed by the restoration of
land preceding the completion of mining.
▪ the choice of site for mine waste should also be considered.
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e. Supply and demand: the relation between how much of a
commodity is available and how much is needed or wanted by the
consumers.
▪ Increase in world demand for any mineral ore will elevate the prices.
▪ The profit from a working mine depends on changes in supply and
demand.
▪ If the demand is too high, mines that were not profitable before
become worth mining.
▪ If the demand falls, working mines may get into a loss due to the
transport and extraction expenses.
Impact of rock and mineral extraction
1. Environmental impacts:
a) Ecological impacts:
i)
Loss of habitat as the vegetation is cleared. Plants do not
have a place to grow and so the animals depending on them for
food and shelter are affected. After deep mining has been
working for several years, more habitats will be destroyed due
to the increased overburden aboveground.
ii)
Pollution:
 Noise pollution: due to machinery and explosives which
disturbs the behavior of animal species and causes hearing
problems for people
 Water pollution: water supplies may also be polluted, making
it unsafe for people to drink.
The water may become acidic and dissolve toxic metal ions-this
combination kills many aquatic organisms.
 Bioaccumulation: organisms absorb the ions and retain them
in their body, reaching concentration higher than that in water.
 Bio magnification: the concentrations increase higher up in
the food chain and cause the death of top consumers.
 Land pollution: toxic nature of the waste doesn’t allow plant
growth even years after the mining is stopped.
 Air pollution: dust particles settle on the vegetation, not
allowing sunlight to reach the leaves and thus, reducing the
rate of photosynthesis.
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Breathing in dust that remains in the lungs can cause serious
lung diseases.
 Visual pollution: landscape is damaged.
iii)
Waste management: mine waste must be stored to prevent
collapse.
2. Economic impacts:
a) Provides employment for people and taxes for the government.
 Jobs are created directly to extract the mineral;
▪ Further jobs are created to supply transport and mining
equipment;
▪ More jobs are created when the mineral is refined to make
products
▪ If all these activities occur in the same country, it will generate
the most income
▪ Earn foreign exchange
b) The income earned can be used for buying goods and services and
investing in infrastructure projects.
▪ Improvements to transport;
▪ Improvements to services, like healthcare and education;
▪ These services can be helpful for miners and their families too;
▪ investing in infrastructure projects can help the country in
building more well-designed communities.
3. Social impacts of mining
A mining development can have both positive and negative effects
of wellbeing of individuals and families within the community in
which it is based.
Social benefits
1.
2.
3.
Offers employment opportunities
Better paid work raises living standards for many
New transport, communication networks, water
supplies and waste disposal infrastructure built for
the mines also improves the quality of life.
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4.
People may also benefit from social community
development projects paid for by the mines e.g. a
new playing field or sports hall.
5.
Free or cheap access to mine facilities such as
hospitals, schools or sport facilities.
6.
Mine workers may be entitled to free or subsidized
housing as part of their benefits
7.
Employees receive career development training at
the mine.
Social problems
1. Sudden rises in disposable income can lead to higher
rates of alcohol and drug use, social nuisance and
crime.
2. Divisions may arise in the community between those
who benefit and those who do not.
3. Resentment can arise in situations where people are
displaced from their land and properties to make way
for a mine.
4. Conflicts may arise when mining corporations fail to
understand the cultural and spiritual importance of the
environment to the indigenous people.
5. Maintaining traditional ways of life can become difficult
when many outsiders arrive with different lifestyles that
may be very attractive to the young.
6. Air, noise and water pollution that the community may
have to cope with.
Managing the impacts of rock and mineral extraction
https://www.youtube.com/watch?v=vpK9XXO7a_E
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This is initially done during Environmental Impact Assessment before a mining
license is issued to the mining company.
This should start with plans for safe waste disposal and end with plans to
return the land to its original state when mining is over.
1. Safe disposal of mining waste.
Safe storage and disposal of mine waste is one of the most important aspects of
any mining license application.
 Mine waste must be stored to prevent collapse
 Site of the mine must prevent the chances of water pollution
 The waste must be monitored to detect any movement or further
pollution
2. Land restoration:
Mining sites are returned to their pre-mine use. Care is taken to rebuild the
ecosystem, through establishing native trees and plants close to that which
existed before the environment was disturbed.
(a)Making lakes and nature reserves
Nature reserves may also be created. This may incorporate lakes that are formed
in open-cast mining areas.
Stanwick lakes nature reserves, UK, created from a disused gravel quarry.
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Butchart Garden, Canada is a nature reserve which was once a limestone quarry.
The nature reserve become valuable green space for human recreation and help in maintaining
biodiversity.
https://www.youtube.com/watch?v=262KealkrCo
(b) Soil improvement:
After sanitary landfilling, mine waste can be covered by a layer of soil that
can be enriched with fertilizers.
(c) Tree planting:
After improving the soil fertility, plants and trees can be grown in that area,
helping an
ecosystem to
be reborn.
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(d) Bioremediation: This is a process of removing pollutants from waste using
living organisms. This can be done through:
(a) In situ treatment: treatment of contaminated wastes where it’s left.
(b) Ex situ treatment: Involves the removal of contaminated waste from a
site to a treatment plant.
This process happens slowly, where micro-organisms like bacteria are
introduced. They can absorb pollutants and metabolize them into harmless
substances.
Plants can also be grown there where they can bio-accumulate toxic
metals.
After these plants have grown for a while, the above ground parts are
removed so that the wastes in the ground become less toxic.
(e) Use as landfill sites:
(i)
Landfilling: This is where the waste is tipped into a hole; from time
to time it is leveled off and compacted.
(ii) Sanitary landfilling: Just like in landfilling, the waste is used to fill
the hole, but alternative layers of waste and sand are used.
https://www.youtube.com/watch?v=qe4-wuWcP_A
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Sustainable use of rocks and minerals
Sustainable use means use that meets the need of the present without affecting the
ability of future generations to meet their needs.
However, the supply of rocks and minerals that is used as building materials and
for industrial production is finite.
Human societies need to use any resource with care, so its use is at least more
sustainable than it has been in the past.
Many countries have already introduced conservation or resource management
plan (based on sustainable development) for rocks and minerals to help ensure
their long term existence.
Sustainable development refers to the development that meets the needs of the
present, without compromising the ability of future generations to meet their own
needs.
The principle of sustainable development of rocks and minerals aims at improving
economic growth and lifestyle, while preserving the natural resources and
ecosystems on which everyone depends.
The sustainable development of the reserve of any rock or mineral must take into
account environmental, economic and social factors.
Rocks and minerals are essential to support economic growth and to maintain and
improve the prosperity and quality of life of people everywhere.
National laws and international agreements encourage sustainable development of
resources.
https://www.youtube.com/watch?v=DDkCcfpcBSM
Strategies for the sustainable use of rocks and minerals
1. Increasing the efficiency of extraction of rocks and minerals. This can be
done through:
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a. Mine wastes being processed for the second time. This allows the
valuable minerals to be removed and reduces the risk of pollution due to
mine wastes.
b. Chemical treatment of the waste and biological treatment using
microorganism extract much of the valuable mineral still within it.
c. Improvements in the performance of the machines used in mining and
processing.
d. Greater use of data analysis by computers to indicate the amount and
ensure complete extraction of ores from a mine.
2. Increasing the efficiency of the use of rocks and minerals.
Attempts to use minerals such as metals more efficiently include engineering
solutions e.g. it is possible to design steel beams used in buildings to have
the same strength but use less steel.
3. The need to recycle rocks and minerals.
(a) Recycling materials such as steel uses less energy than processing new
ones from the ores.
(b) Recycling also produces less waste and thus reduces the risk of pollution.
4. Legislation
The governments pass laws that require manufacturers to become
responsible for recycling and reuse of materials. For example, the mineral
wastes must be used as road aggregate or additives in cement manufacture.
Activity to be done during the lesson
1. Aluminum is produced from bauxite. Five tonnes of bright red bauxite
are made into 2 tonnes of a white powder called alumina (aluminium
oxide) in an alumina plant. The bauxite is usually obtained from open-pit
mines. Hot caustic soda solution is added to the crushed rock to get rid of
impurities. The alumina is then converted into 1 tonne of aluminium in a
smelter. An electric current is passed through the alumina and molten
aluminium is siphoned off.
(a) State the name given to any rock that contains a valuable metal. (1)
(b) Calculate the mass of solid waste that would be produced from the
processing of 25 tonnes of bauxite. (3)
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(c) Calculate the mass of bauxite that would be needed to produce 25
tonnes of aluminium (1)
(d) Suggest two environmental consequences of aluminium production
after the bauxite has been mined(2)
(e) Explain how the landscape may be restored after bauxite mining is
finished (3)
Total 10 marks
Case studies
Group research and presentations
(This work contributes 20 marks to the third weekly assignment and
therefore participation in research, compilation of work and presentation is
mandatory for each group member)
Individual contribution to the group activity must be posted in class material
before our Tuesday lesson.
1. Carry out an extensive research on the development, impact and
management of Islands Copper Mine. In your report include the measures
that were put in place to restore land after the mine had closed.
Each group will be given at least 10 minutes to present their work in slides
with detailed diagrams. (20 marks)
Group 1.
Members
A
B
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2. Carry out an extensive research on the deep water horizon disaster. In your
report include the impact and management of the pollution event.
Each group will be given at least 10 minutes to present their work in slides
with detailed diagrams.
Group 2.
Members
A
B
Energy and the environment
Fossil fuels
They are non- renewable forms of energy such as coal, oil and natural gas. When burnt, they
produce a lot of heat and light energy. They contain far more energy compared to wood. However,
they release carbon back into the atmosphere which is responsible for global warming.
Formation of fossil fuels
(a)Formation of coal
Coal is formed from the dead remains of trees, ferns and other plants. Coal forms on land on
massive peat bogs or swamps
Watch the video through the link below:
https://www.youtube.com/watch?v=QEa36qNo86E
Process of formation of coal
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(a) Accumulation of organic matter (from dead remains of trees, ferns and other plants that
lived in the Carboniferous period i.e. 300-400 million years ago) within a swampy area. They
were buried under large sediments. The decomposing matter was kept out of oxygen and as
time passes, the pressure and temperature increases and gradually ‘cooks’ the matter
transforming it into coal. In some areas, coal formed in swamps that were covered by
seawater containing a large amount of sulfur.
(b) The organic matter was covered and compressed by deposition of a new layer of sediments.
This lead to formation of peat. As sea levels changed (sea/salty water), sulfur was
deposited as part of the sedimentation that buried the decomposing remains. In freshwater
swamps that contained very little sulfur, coal contained very little sulfur so releases very little
sulfur when burnt. Peat consists of partially decomposed vegetation in which you can see
roots and branches.
(c) With greater burial, peat is compressed and heated hence turning into lignite coal which
contains high content of decayed wood. Lignite contains more carbon than peat. Lignite makes
the largest proportion of the world’s coal reserve.
(d) At even greater depths, increased temperatures, pressure and time, sub- bituminous coal
followed by bituminous coal which contains 86% of carbon and is burnt in industrial boilers to
make coke (used in steel making industry).
(e) Eventually anthracite coal is formed. This is the hardest type of coal and contains the most
carbon. When burned, it produces the most heat. It has taken the longest time to form.
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(c)
Formation of oil and natural gas
https://www.youtube.com/watch?v=8YHsxXEVB1M
They are formed mostly by ancient algae and other small marine organisms that lived and
died in oceans.
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Stage 1 - All of the oil and gas we use today began as microscopic plants and animals living in the
ocean millions of years ago. As these microscopic plants and animals lived, they absorbed energy from
the sun, which was stored as carbon molecules in their bodies. When they died, they sank to the
bottom of the sea. Over millions of years, layer after layer of sediment and other plants and bacteria
were formed.
Stage 2 - As they became buried ever deeper, heat and pressure began to rise. The amount of
pressure and the degree of heat, along with the type of biomass, determined if the material became
oil or natural gas. More heat produced lighter oil. Even higher heat or biomass made predominantly of
plant material produced natural gas.
Stage 3 - After oil and natural gas were formed, they tended to migrate through tiny pores in the
surrounding rock. Some oil and natural gas migrated all the way to the surface and escaped. Other oil
and natural gas deposits migrated until they were caught under impermeable layers of rock or clay
where they were trapped. These trapped deposits are where we find oil and natural gas today.
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Energy resources
Energy demand is increasing worldwide. There are a number of reasons for this:
(a) Increasing human population size
(b) Increasing industrialization and urbanization
(c) Improvements in standards of living and expectations
In order to meet the demand for energy, existing sources need to be used more efficiently.
There is need to explore methods that until now, have been too difficult or expensive.
Types of energy sources
Energy sources can be classified into two groups:
A. Non- renewable energy sources: they are a limited source of energy that cannot
be replaced as soon as they are used. They are also called finite source of energy.
B. Renewable energy sources: they are energy sources that can be replaced as soon
as they are used, so they don’t run short in supply. They can be used again and
again.
Classification of energy sources
Renewable energy sources
Geothermal Power
Hydroelectric Power
Tidal Power
Wave Power
Wind Power
Solar Power
Biofuels e.g. bioethanol, biogas and wood
Non-renewable energy sources
Oil
Coal
Natural gas
Nuclear power using uranium
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Note: Nuclear fuels will last for centuries and are seen by many scientists as a more suitable
replacement of fossil fuels. However, the source material (uranium) is only available in limited supply.
As much as it can last for a long time, it cannot be replaced.
WEEK 3 LESSON 1
How Energy sources are used
Energy sources can be used for:
1. Heat and light production through combustion
2. Manufacture of electricity which is mostly generated by
electromagnetic induction.
Electromagnetic induction
https://www.youtube.com/watch?v=AmWEs5CTQ3Q
This process was discovered by Michael Faraday. The process transforms
kinetic energy (energy for movement) into electrical energy using loops
of conducting material such as Copper and a magnet.
Inside the generator, there are coils that are rotated close to the magnet to
generate electricity.
A power source is therefore needed to rotate the coils. This power comes
from a turbine connected to the generator.
Turbines are designed to provide the rotary motion needed in the generator.
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In this simple system,
a) The heat source (combustion) heats the waters in the boiler unit which
is converted into steam.
b) The steam passes through the blades of the turbine (Kinetic energy),
causing them to move.
c) As a result of the rotation on the shaft, the copper coils in the
generator move
d) producing electricity (Electric energy) that is transferred by
conducting wires
e) The electricity is distributed to homes and industries through the
electric grid.
Note:
1. To increase the efficiency of the turbine, more blades need to be fitted
in the turbine and more steam or liquid should also be passed.
2. The heat source used to produce steam can be nuclear reactions,
burning of fossil fuels, geothermal and biofuel power.
How energy sources are used to generate electricity
1. Energy sources such as fossil fuels, biofuels, nuclear and
geothermal power are usually used to heat up water to produce
steam. The steam is then used to turn the turbine which generates
electricity.
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2. Generating electricity using nuclear power( Uranium or
plutonium as fuels)
 Uranium or plutonium decays (undergoes a chain of reaction
called nuclear fission) hence releasing energy in form of heat and
radiation.
 This chemical reaction is controlled in a power station reactor called
containment structure.
 Water is pumped into the reactor (containment structure).
 Reactor heats up water due to thermal energy produced.
 Water is turned into steam/ vapor.
 Steam passes through the blades in the turbine (Kinetic energy),
causing them to move.
 As a result of the rotation on the shaft, the copper coils in the
generator move
 Producing electricity (Electric energy) that is transferred by
conductive wires
 The electricity is distributed to homes and industries through the
electric grid.
Week 3 lesson 2
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Generation of electricity using geothermal source
https://www.youtube.com/watch?v=eyOXmqu4PS8&
t=12s
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Boreholes are drilled in which one pipe injects cold water to the hot
rocks in the ground.
Note: The rocks must have fractures.
The water is heated up into steam and is pumped out to the surface
under high pressure through production wells and directed into heat
exchanger where incoming cold water is heated up into steam and used
to drive the turbine that is used to generate electricity in the generator.
Generating electricity using Wind power
It is used to turn turbine directly without the need to produce steam first.
https://www.awea.org/wind-101/basics-of-wind-energy
In this turbine, the gear box is used to maximize the rotation of the shaft
as it enters the generator. The break will slow down or stop the rotor
blade in very windy conditions to prevent the blade being damaged.
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b. Tidal power uses the natural rise and fall in the level of water in an
area during the day. As water levels drop, it is held up by a tidal
barrage- a small dam that releases water back through a turbine which
in turn generates electricity using a generator.
Note: The amount of power that is generated is dependent on the change in
the tide level throughout the day. Watch a video through the link below
https://www.youtube.com/watch?v=VkTRcTyDSyk
Generating electricity using Wave power also uses turbine and
generator to generate electricity.
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https://www.youtube.com/watch?v=gcStpg3i5V8
It uses the small differences in water levels that are caused by
wind action. Power is produced by channeling the energy of waves at
sea rather than by tides.
Note: Unlike tidal power, wave power is not limited to the regular
pattern of tides. However, electricity generation may stop when calm
weather conditions mean that there is little or no wave production in the
area.
Week 3 lesson 3
Hydro-electric power generation
Water from the reservoir flows through intake dam where it causes turbine
to rotate. This turns the generator hence producing electricity.
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c. Solar power: Is one exception in the way that electricity is produced.
Most electricity produced by this method uses photovoltaic cells.
Watch a video through the link given below
https://www.youtube.com/watch?v=0elhIcPVtKE
Sunlight hits the surface of the photovoltaic cells
A material called a semi- conductor converts the light into electricity
Even though the electricity produced by one cell is small, a bank of cells
organized into a solar array, can produce a significant amount of electricity.
Week 4 lesson 1
Factors to consider when choosing the type of
energy sources to use
Deciding which energy source to use is not always easy because of different
economic, social and environmental impacts. One source of power may
have both advantages and disadvantages.
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Economic factors
Energy supply is expensive, particularly in a world where the demand is ever
increasing and the supply from the main source is limited. If energy is in
high demand and in short supply, then the price for that item rises.
Social factors
The impact of different fuel sources will depend on the local area and the
industry that it supports.
Positive impacts
1. New industries might mean greater local employment
2. Increase in industry locally might also mean that other businesses are
needed to supply the needs of the energy business and its workers.
3. Large scale projects could provide improvements to the local
infrastructure e.g. roads, supply of water, electricity, healthcare and
schooling.
4. The development of new technologies might be a great asset to a
community if it brings new manufacturing opportunities to the area.
Negative impacts
1. The mining of coal or drilling for oil might mean that the land is no longer
viable for agricultural use.
2. Energy business could also cause the displacement of a whole community
3. The investment in certain energy sources might have health effects for
the local population e.g. dust from extraction, noxious fumes from
combustion or risk of radiation from nuclear power.
Environmental factors
This will vary from a region to region.
1. Global warming: burning of fossils fuels are a major contributor to
carbon dioxide in the atmosphere.
2. Pollution: Spillage of fuel into the environments e.g. oil spills to the
oceans, can cause damage to wildlife.
3. Changes to the ecosystem: extraction of fuels from underground can
destroy habitats for a range of animals or their food source.
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4. Visual impact: The nature of the landscape can be changed e.g. large
areas of solar panels or wind turbines impact on an area’s natural beauty
as well as changing the local ecosystems.
Week 4 lesson 2
Advantages and disadvantages of different fuel types
Fuel type
Fossil
fuels(oil,
coal, natural
gas)
Nuclear
power (using
uranium)
Advantages
Disadvantages
d. Plentiful supply in some
locations
e. Extraction provides jobs
f. The fuel is available for most
countries to use
i. Does not produce CO2 hence
not
leading
to
climate
change
j. Small
amounts
of
fuel
produces large amounts of
energy
k. Power plants employ lots of
people
o. They are a renewable source
of energy
p. Growing more plants uses a
lot of carbon dioxide
q. Potentially plentiful in supply
g. CO2 emission causes
global warming
h. Toxic gases e.g. SO2
and NOX are produced
Geothermal
power
u. Does not produce carbon
dioxide
v. Unlimited supply as uses the
heat from the earth as a
source of power
l. Risk
of
radiation
leakage which causes
cancer
m. Waste
products
cannot be recycled as
radiation active for
centuries
n. Limited supply
r. Produces
CO2
and
other and other toxic
gases when burnt
s. A lot of land is needed
to grow crop for fuel
t. Potential removal of
natural ecosystems to
grow fuel crop
w. Can be expensive to
stall
x. Only
certain
areas
have
suitable
conditions
Hydroelectric
power
y. Does not produce carbon
dioxide
z. Water can be reused for
other purposes
aa.
Building of dams
impact the natural
flow of water
bb.
Villages
and
Biofuels
(Bioethanol,
biogas, wood
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Tidal power
Wave power
cc. Does not produce carbon
dioxide
dd.
Tidal movements are
not dependent on weather
conditions
gg.
Does
not
produce
carbon dioxide
hh.
A renewable source of
power
Solar power
kk.
Does
not
produce
carbon dioxide
ll. Sunlight is not a limited
resource
Wind power
pp.
Does
not
produce
carbon dioxide
qq.
A renewable resource
ecosystems may be
destroyed when dams
and
reservoirs
are
built
ee.
Limited
to
specific coastal areas
ff. Impacts
on
the
tourism industry and
local fishers
ii. Limited
to
specific
coastal areas
jj. Currently not very
efficient,
so
large
amounts of resources
needed
mm.
Only
efficient
under certain weather
conditions
nn.
Generation only
occurs
in
daylight
hours
oo.
Visual
impact
and potential damage
to local ecosystems
rr. Not all locations are
suitable
ss. Generation
only
occurs
in
certain
conditions (at certain
wind speeds)
tt. Visual impact
uu.
Uses
a
large
area.
The demand for energy
https://www.youtube.com/watch?v=-RSrviqvAmY
Global energy demand video for today
There is a predicted increase in human use of energy over the next 40
years. However, there will also be a challenge of limited supply of nonrenewable resources.
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World price of non-renewable energy sources will continue to rise with
the increase in demand.
A review of the energy use within different countries shows that there is
a significant difference in the amount of energy used per person of
different populations.
Factors contributing to increase in energy demand:
a. Industrial demand: Manufacturing requires the use of large
quantities of energy in all stages of production. Iron and steel
production has an extremely large energy demand, using fuel to
melt iron ore and refine it.
b. Domestic demand: The impact of more efficient manufacturing
processes has meant that many goods have become more affordable
e.g. TVs that were once seen in the homes of high income earners in
the developed world was because they were expensive to produce.
Today, many people can afford cars, computers, mobile phones,
fridges etc. All these use energy.
c. Transport demand
The drive to develop efficient systems of production has meant
that in many locations manufacturers are supplying customers
across the globe. This leads to increased cost of transportation.
Shipping journeys have increased fourfold in the past 20 years.
There has also been a significant increase in the amount of air
transport. Both air and shipping journeys requires large amount of
fossil fuels to operate.
d. Economic factors
In a small scale, within a family:
If economic conditions are good, there will be a higher
employment and more money to spend on luxury items which use
energy.
If economic conditions are poor, families will have less available
money and will make saving, which could include reducing the use
of fuels and the purchase and use of electrical items which uses
energy.
In a national level, within the economy of a country, if a country
has less income because of a reduction in manufacturing, it will
have less ability to import foreign goods.
A poor economy will mean:
 Less manufacturing(less energy used)
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 Fewer goods to transport (less energy used)
 An inability to purchase foreign energy supplies
Reduction in the manufacturing in one country can have an impact in
the global economy.
e. Climate: energy usage in one country is also complicated by the
prevailing weather conditions e.g. people living in a temperate
climate are likely to experience colder winters than those living in a
more equatorial climate. The energy demand for heating in colder
climates is likely to be far higher.
In the winter months, fewer hours of daylight means more electric
lighting is required.
Week 5 lesson 1
Conservation and management of energy resources
Strategies for effective energy use
1. Reduce consumption:
The demand for energy is greater than supply. The following are ways in
which energy consumption can be reduced:
 In the case of fuels such as petroleum, fuel rationing is normally
considered.
 More energy efficient technology and new building design and planning
that take into account energy use.
 Reducing lighting, shutting down elevators and turning off air
conditioning(turning electric devices off)
2. Changing the energy mix: By shifting electricity production towards
renewable energy sources. This can reduce the demand for nonrenewable energy source.
3. Education: By educating people from young age about the need to save
energy will help transform behaviors and ultimately lead to reduction in
energy use.
4. Vehicles:
 Through increasing fuel efficiency of vehicles- making them go
further for every liter of fuel burned.
 Making cars out of lighter materials will also allow them to use less
energy as the fuel taken to accelerate will be reduced.
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

5.
6.
7.
Taxing of older, less efficient and more polluting vehicles, will lead
to people shifting towards more fuel-efficient vehicles, which in turn
lead to reduced energy demand.
 Using biofuels e.g. Biodiesel, bioethanol which powers every light
vehicle in Brazil and USA.
Developing hybrid cars that use petrol engine that charges an electric
power unit and the car that will switch between each unit to maximize
fuel consumption. There are also fully electric vehicles available with no
petrol engine at all. They require charging every day and use electricity,
which may come from fossil fuels. These cars cause less pollution.
Energy from waste:
 Anaerobic digestion is the breaking down of organic waste e.g.
waste food and vegetation using bacterial. It takes place in a
sealed container and produces methane; a flammable gas can be
used for a variety of heating purposes.
 Household rubbish can be burnt to produce heat which can be used
to generate electricity.
 Cooking oils once used in food processing industries need to be
disposed of. They can be collected and recycled into biofuels
suitable for running vehicles.
Government policy: In Singapore, the government introduced a highly
successful MRT (mass rapid transport) system of underground trains
that run cheaply and efficiently, alongside ERP (Electronic road
pricing) and a variable tax rate for vehicles where owners have to buy
10 years of road tax upfront. This makes cars very expensive in
Singapore.
Research and development into alternative energy sources being
produced. For example:
 Oil from tar sand in Alberta , Canada
 Deep water oil production off the coast of Brazil
 Innovation in the development of solar panels
 Developing large scale wave generation scheme
 Fracking: The process of drilling down into the earth before a high
pressure water mixture is directed at the rock to release the gas
inside
 Researching methods to extract oil from deep in wells that cannot
be accessed through current techniques.
Week 5 lesson 2
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Impact of oil pollution
Oil is transported from the source to the refinery and from there onwards to
a variety of distribution networks. Oil is transported across the oceans in
large ships or across land using pipelines. During the process of
transportation, oil can enter marine or coastal ecosystems and cause
significant pollution:
Causes of oil pollution
a. Offshore oil extraction: when oil is extracted offshore, there is a
greater risk of an uncontained oil spill on the land. Oil can also enter
marine and coastal ecosystems if the oil-well head on the seabed is
damaged.
Oil can also be leaked if the equipment is outdated or poorly maintained.
It can also be spilled when being transferred to ships or through
pipelines to shore.
b. Pipelines: oil pipelines are the most common method of transporting oil
on land. The pipes sometimes leak due to corrosion, metal fatigue and
human error in construction. There have been a lot of recorded oil spills
across the world into nearby rivers causing devastating effects.
c. Shipping: There have been a number of high-profile oil tanker spills that
dumped large quantities of crude oil directly to the sea. They were
caused by weather, metal fatigue, collisions and navigation errors. They
have had a devastating effect on seabirds, sea otters and seals.
Impact of oil pollution on marine and coastal ecosystems
https://ocean.si.edu/planet-ocean/tides-currents/gulf-oil-spilleffects-marine-life
Regardless of the cause of the oil spill, the impact can be very
significant.
Oil floats on salt water and spreads out rapidly to form an oil slick. The
slick thins out to leave a thin sheen of oil on the water.
1. Oil floats on the surface of the water and prevents light from entering
hence preventing phytoplankton from photosynthesizing hence they
die.
2. Oil floating on water surface prevents gas exchange hence fish will
die. Oil coming in contact with gills also affects fish.
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3. Birds die due to lack of food such as fish. They may consume oil when
eating fish, feathers become coated in oil when hunting for food hence
affecting their ability to fly and buoyancy.
4. Marine mammals may swallow oil while feeding, which will be toxic to
them. A coating of oil will affect their skin.
5. Areas of coral reef may become covered with oil which might cause
complete devastation due to lack of oxygen.
6. Oil is often washed by tides, coating rocks on beaches. Organisms
living in shallow water and rock pools may be killed by the toxic
effects of the oil.
7. Reduction in population of fish will affect livelihoods of fishermen as
well as the availability of food for locals.
8. Oil on beaches can have an impact on tourism by reducing an area’s
attractiveness as a holiday destination.
Management of oil pollution
https://www.youtube.com/watch?v=_tq91E9WRRY
As long as oil is being used and transported, there will continue to be oil
pollution incidents.
Given the environmental, economic and social costs of oil spills, there
have been attempts to develop strategies for reducing oil spills in marine
and coastal ecosystems.
Strategies for reducing oil spills in marine and coastal
ecosystems
1. MARPOL (MARINE POLLUTION) (International Convention for
the Prevention of Pollution from Ships)
A number of high profile oil spills led to the development of a new
international marine treaty in 1973, which was amended in 1978 and
came into force in 1983. MARPOL was designed to eliminate marine
pollution in the sea. Prior to MARPOL, it was common for ships to
dispose of waste or clean their storage tanks in the middle of the
ocean. All tankers must be certified to show they have appropriate
systems in place and records to show that they are being used.
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2. Tanker design:
In 1992, MARPOL was updated to include regulations that require oil
tankers to be fitted with double hulls that protect the cargo in the
event of a collision. Single-hulled tankers have been phased out and
there are strict regulations on how the oil should be carried. A doublehulled ship is one that has been built with two hulls, so that if there is
damage to the outer layer (or plate) the contents are still held
securely by the inner plate
Dealing with oil spills
Even with new technology and international laws, accidents do happen and
oil enters marine and coastal ecosystems. Each spill is different in terms of
the amount and type of oil, the environment affected and the clean-up
options.
The technique used to clean-up will depend very much on local weather
conditions, the proximity to land and calmness of the sea.
There are several methods that are deployed in most oil spills.
1. Booms: Refers to temporary floating barriers to oil which can prevent
the oil from spreading. These are less effective in high waves.
2. Chemical dispersants and biological agents: they breakdown oil into
very small droplets, which can be biodegradable. They are delivered by
specialized boats and planes
3. Skimmers: are boats that skim (collect) spill oil from the water’s surface
for processing and recovery.
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4. Sorbents: material like peat moss, which are used to absorb oil.
5. Controlled burning: a method of burning freshly spilled oil, usually
while it is floating on the water that is surrounded by booms
6. High-pressure hoses: for washing oil off beaches.
7. Vacuum trucks: to remove spilled oil from beaches or the water’s
surface.
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