© Boardworks Ltd 20051 of 35
I.S.Science
Energy Resources
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Contents
Energy Resources
Types of energy resources
Non-renewable fuels
Comparing fuels
Summary activities
Electricity from fuels
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Sources of energy
What are the sources for most of the energy on Earth?
3. Radioactive elements made in supernova explosions are another source of energy.
1. The vast majority of the energy resources on Earth can trace their energy back to the Sun.
2. The Moon is another source of energy.
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Energy resources
What energy resources are shown in this scene?
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Types of energy resource
There are two types of energy resource:
Renewable energy resources will never run out (at least not for a very long time), or can be regenerated.
Examples: w___ and S__.
Non-renewable energy resources will eventually run out – once used they cannot be used again.
Examples: c___ and o_.ind un oal il
Non-renewableRenewable
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Energy resources
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Energy Resources
Types of energy resources
Non-renewable fuels
Comparing fuels
Summary activities
Electricity from fuels
Contents
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Fossil fuels
What is a fuel?
What is a fossil fuel?
Name three fossil fuels:1. ___________2. ___________3. ___________
A fuel is a store of (chemical) energy.
A fossil fuel is a fuel formed from the remains of animals and plants over millions of years.
OilNatural gas
Coal
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How coal formed
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How coal formed
Over millions of years, due to high temperatures and pressure…
…the trees became fossilized, forming coal.
Millions of years ago trees died and fell to the bottom of swamps.
Over time they became covered by mud and rock.
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How oil and natural gas formed
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How oil and natural gas formed
Over millions of years, due to high temperatures and pressure…
…the plankton became oil and natural gas.
Millions of years ago plankton died and fell to the bottom of seas and oceans.
Over time they became covered by mud and rock.
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What process releases the nuclear energy?
What fuels are used in nuclear power stations?
Nuclear fuels
Uranium and plutonium
Nuclear fission
A large amount of energy for a small amount of fuel, no acid rain, no greenhouse effect, cheap to run once built.
What are the main advantages of nuclear power?
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Energy Resources
Types of energy resources
Non-renewable fuels
Comparing fuels
Summary activities
Electricity from fuels
Contents
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Fossil fuel power stations
Fossil fuel power stations convert c______ energy into e______ energy.
hemicallectrical
Oil and coal fired power stations work in a very similar way. The fuel is burnt and the heat boils water to make high pressure superheated steam, which is used to turn a turbine.
Natural gas fired power stations do not use steam. The natural gas is burnt, which produces hot gases that turn the turbine directly.
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What happens in a power station?
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Energy changes in a power station
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Nuclear power stations convert n_____ energy into e______ energy.
Nuclear power stations
In a nuclear power station the fuel is not burnt; instead it undergoes a fission reaction in the nuclear reactor, which releases heat.
Like in a coal fired power station the heat is used to make high pressure steam.
What are the energy transfers in a nuclear power station?
Reactor Turbine Generator
nuclear heat kinetic electrical
uclearlectrical
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Start-up times
Power stations cannot just be turned on at the flick of a switch. They need to be started up – this process can take days!
The graph below shows the typical start-up times for different types of power station
0
10
20
30
40
50
naturalgas
oil coal nuclear
hour
s
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Processes in a power station
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Energy Resources
Types of energy resources
Non-renewable fuels
Comparing fuels
Summary activities
Electricity from fuels
Contents
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Burning fossil fuels
burn in oxygen
heat energyashcarbon dioxidesulfur dioxide
Fossil fuels are cheap and the heat energy is useful.
However, there are problems with burning fossil fuels:
ash is a waste product that needs to be disposed; carbon dioxide causes the greenhouse effect; sulfur dioxide causes acid rain.
What is produced when fossil fuels are burnt?
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The greenhouse effect
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This results in the Earth getting w_____. This effect is called the g e . G w results in the icecaps melting, which could lead to flooding and changing weather patterns.
Global warming
C_____ d_____ is a greenhouse gas – it lets the Sun’s heat energy into the Earth’s a_________ but it will not let it escape.
tmosphere
armer
arbon ioxide
reenhouse ffect lobal arming
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Carbon dioxide from fuels
Some fossil fuels release less carbon dioxide when burnt than others.
0
20
40
60
80
100
coal oil natural gas
The graph below shows the relative amounts of carbon dioxide released per unit of electricity produced:
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Acid rain
Burning fossil fuels containing sulfur causes sulfur dioxide to be formed. This gas is released by power stations and mixes with water in the atmosphere to form acid rain.
sulfur in coal sulfur dioxide acid rain
combustion mixed with water
What does acid rain do to the environment?
kills trees
kills water life
corrodes buildings and statues
acidifies soil
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Reducing acid rain
Acid rain is mostly caused by sulfur dioxide (which forms sulfuric acid), but carbon dioxide also contributes (by forming carbonic acid).
How can acid rain be reduced?
1. Burn fewer fossil fuels – generate electricity in other ways.
2. Remove sulfur from oil and natural gas before it is burnt.
3. Scrub waste gases to remove sulfur dioxide.
4. Use expensive coal that contains little sulfur.
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Pros and cons of fossil fuels
Advantages Disadvantages
non-renewable
acid rain
greenhouse effect
readily available
easily transported
low fuel cost
low building costs
short start-up times
inefficient
Although there are problems burning fossil fuels in power stations there are also advantages:
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Pros and cons of nuclear power
Advantages DisadvantagesExpensive to buildExpensive to decommission
Radioactive waste
Cheap to runConserves fossil fuelsNo sulfur dioxideemissionsNo carbon dioxideemissionsSafe undernormal conditions
Links with cancer
Although there are problems in the use of nuclear power, there are also advantages:
Little fuel used meansless transport needed
Non-renewable
Risk of disaster
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Fuel reserves
Fuel Time until reserves run out (years)
natural gasoil
coal
nuclear
25-30
about 300
about 75
thousands
coaloilnatural gas
nuclear
Even though nuclear fuel will last thousands of year it will still run out eventually.
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Energy Resources
Types of energy resources
Non-renewable fuels
Comparing fuels
Summary activities
Electricity from fuels
Contents
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Glossaryacid rain – Rainwater that is more acidic than normal
because acidic gases have dissolved in it.fossil fuel – A fuel made from the remains of decayed
plants or animals.generator – A device that transforms kinetic energy into
electrical energy.global warming – The increase in the temperature of the
Earth, which some scientists think is causing climate change.greenhouse effect – The trapping of heat from the Sun
by certain gases in the Earth’s atmosphere.non-renewable – An energy source that cannot be used
again.renewable – An energy source that can be regenerated.turbine – A device that turns heat energy into kinetic
energy.
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Anagrams
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Energy resources
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Multiple-choice quiz