EDEXCEL IGCSE PHYSICS 4-4

Energy Resources and Electricity Generation

Edexcel IGCSE Physics pages 150 to 159

December 4th 2010

Content applying to Triple Science only is shown in red type on the next slide and is indicated on

subsequent slides by ‘TRIPLE ONLY’

THIS POWERPOINT IS NOT DUE FOR COMPLETION UNTIL

JULY 2012

Edexcel IGCSE SpecificationSection 4: Energy resources and energy transfer d) Energy resources and electricity generation

understand the energy transfers involved in generating electricity using:

• wind

• water

• geothermal resources

• solar heating systems

• solar cells

• fossil fuels

• nuclear power

describe the advantages and disadvantages of methods of large-scale electricity production from various renewable and non-renewable resources.

Red type: Triple Science Only

Thermal power stationsA thermal power station generates electricity by using the heat produced by the burning a fossil fuel such as coal, gas, oil or by the fission of uranium.

Over 90% of our electricity is produced by these type of power stations.

Thermal power station block diagram

BOILER

Fuel is burnt to turn water into high pressure steam.

TURBINE

High pressure steam turns a turbine (like a windmill)

GENERATOR

The turbine rotates the coils of a generator to produce electricity.

BOILER TURBINES GENERATOR

Coal-fired power station

A nuclear reactor

Comparison of uranium and fossil fuels

uranium coal, gas, oil

Energy released per kg of fuel

1 000 000 kWh 100 kWh

Wasteradioactive waste that needs to be stored for

many years

non-radioactive waste

Greenhouse gases None

Yes, mostly carbon dioxide

Choose appropriate words to fill in the gaps below:

Most of our electricity is produced by __________ power stations. These use the _______ produced by burning _____ or the fission of __________ to generate electricity.

The heat produced is used to change ________ into high pressure steam. This steam is used to turn a _________ which in turn _________ an electrical generator.

Over _______ of our electricity is generated by using thermal power stations.

fuels uranium

turbine

rotates

water

heat

thermal

WORD SELECTION:

90%

fuels

uranium

turbine

rotates

water

heat

thermal

90%

SimulationsPower Station Animation - eChalk Generator - Fendt Nuclear Fission - Powerpoint presentation by Richard Miller of 5SJW (2005) Nuclear Fission - Powerpoint presentation that includes a link to the 'mousetrap' demonstration Nuclear Physics - PhET - Start a chain reaction, or introduce non-radioactive isotopes to prevent one. Watch alpha particles escape from a Polonium nucleus, causing radioactive alpha decay. Control energy production in a nuclear reactor! Chain reaction demonstration using mousetraps - University of Michigan

BBC Bitesize Revision: Introduction Page on AQA Generating Electricity Test Bite on Generating Electricity BBC Bitesize Revision: Fossil Fuels Nuclear Fuels Comparing Sources - includes short and long term costs Test Bite on Generating Electricity

Renewable energy sourcesA renewable energy resource is one that will not run out.

Renewable energy sources do not produce radioactive waste, greenhouse gases or acid rain.

Examples include wind, hydroelectric, wave, tidal, solar and geothermal.

Fossil fuels such as coal. gas and oil as well as uranium are non-renewable energy sources.

Wind power

Wind is used to drive a turbine directly which rotates an electrical generator.

A wind farm

Wind power versus thermal power stations

ADVANTAGES • Renewable energy source• No greenhouse gases• No acid rain• No radioactive waste• Inexpensive to build• Short start up time

DISADVANTAGES• Unreliable – needs wind!• Best used in places where

they will often be regarded as unsightly

• Many turbines are needed to produce the same energy of a small thermal power station

• Noise• Danger to wildlife

Wave power

Waves can be used to drive an electrical generator.

Wave power versus thermal power stations

ADVANTAGES • Renewable • No greenhouse gases• No acid rain• No radioactive waste• No land needed• Short start up time

DISADVANTAGES• Unreliable• Can only be used in areas

with suitable waves• Prone to storm damage• Many needed to produce

the same energy of a small thermal power station

• Danger to shipping

Hydroelectric powerFalling water is used to drive a turbine directly which rotates an electrical generator.

The Hoover Dam near Las Vegas

Hydroelectric power station

Hydroelectric power versus thermal power stations

ADVANTAGES • Renewable • Can produce as much energy as a thermal power station

• No greenhouse gases• No acid rain• No radioactive waste• Short start up time

DISADVANTAGES• Can only be used in mountainous areas

• A large amount of land needs to be flooded

• Expensive to build

Tidal powerMoving water caused by the tides is used to drive a turbine directly which rotates an electrical generator.

Proposed Severn Estuary Tidal Power Scheme

Tidal power station at La Rance, Brittany

Tidal power station

Tidal power versus thermal power stations

ADVANTAGES • Renewable • No greenhouse gases• No acid rain• No radioactive waste• Short start up time

DISADVANTAGES• Very limited locations• Wildlife affected• Expensive to build

SimulationsWind Energy Wave, Tidal & HEP

Solar power (cells)

Electricity can be produced directly from the Sun’s radiation using solar cells.

Solar power (panels)Solar panels are used to heat water saving electricity or gas use.

Solar power versus thermal power stations

ADVANTAGES • Renewable • No greenhouse gases• No acid rain• No radioactive waste• Short start up time

DISADVANTAGES• Unreliable in the UK! –

sunshine is needed for solar cells

• Can only be used during the day

• Only 10% of solar energy is converted into electricity by solar cells

• Many cells needed to produce the same energy of a small thermal power station

Geothermal energy

In some volcanic areas hot water and steam rise to the surface. The steam can be tapped and used to drive turbines. This is known as geothermal energy.

Geothermal versus thermal power stations

ADVANTAGES • Renewable • No greenhouse gases• No acid rain• No radioactive waste• Short start up time

DISADVANTAGES• Very limited locations• Expensive to build

Electricity generation pie-chart

Most of our electricity is generated by burning fossil fuels (74% according to the pie chart opposite)

Nearly 20% is nuclear

Less than 5% is currently generated using renewable sources.

Problems with fossil fuels

Burning coal, gas and oil produces carbon dioxide. This is a greenhouse gas which causes global warming.

Fossil fuel burning can also produce sulfur dioxide gas. This can dissolve in water and produce acid rain which causes damage to forests and buildings. Modern power stations remove most sulfur dioxide producing compounds before burning.

Fossil fuels are not renewable. They are running out. Estimates vary between 50 to 200 years to when we will need to find alternative sources of energy.

An effect of acid rain

Problems with nuclear power stationsNuclear fuel (uranium) does not produce greenhouse gases and it generates 10000 times more energy per kilogram than fossil fuels.

However:

Nuclear waste is radioactive and may have to be stored safely for thousands of years.

Although safe in normal operation, accidents can release radioactive material over a large area. The area around Chernobyl in Ukraine has been closed off since 1986. The destroyed Chernobyl

nuclear reactor

Choose appropriate words to fill in the gaps below:

Renewable energy sources will not _____ out and they do not cause __________ gases, acid rain or radioactive waste.

However, most of our ___________ is produced using non-renewable sources such as ______ fuels (coal, gas and oil) and _________. These are highly concentrated and ________ energy sources.

In the near future we hope to use more renewable sources such as wind, wave and _______ power. This will help us to conserve the remaining _______________ energy sources.

reliable

electricity

greenhouse

non-renewablefossil

run

uranium

WORD SELECTION:

tidal

reliable

electricity

greenhouse

non-renewable

fossil

run

uranium

tidal

Energy Resources

and Electricity Generation Notes questions from pages 150 to 159

1. Answer the questions on page 159.2. Verify that you can do all of the items

listed in the end of chapter checklist on page 159.

Online Simulations