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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