EDEXCEL IGCSE PHYSICS 4-4 Energy Resources and Electricity Generation THIS POWERPOINT IS NOT DUE FOR COMPLETION UNTIL JULY 2012 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’

Edexcel IGCSE Specification Section 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 stations A 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 TURBINES GENERATOR 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.

Coal-fired power station

A nuclear reactor

Comparison of uranium and fossil fuels coal, gas, oil Energy released per kg of fuel 1 000 000 kWh 100 kWh radioactive waste that needs to be stored for many years non-radioactive waste Waste Greenhouse gases Yes, mostly carbon dioxide None

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. thermal fuels heat uranium water turbine rotates 90% WORD SELECTION: rotates fuels heat 90% uranium turbine water thermal

Simulations Power 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 Fossil Fuels Nuclear Fuels Comparing Sources - includes short and long term costs

Renewable energy sources A 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 power Falling 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 power Moving water caused by the tides is used to drive a turbine directly which rotates an electrical generator. Tidal power station at La Rance, Brittany Proposed Severn Estuary Tidal Power Scheme

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

Simulations Wind 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 stations Nuclear 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. run greenhouse electricity fossil uranium reliable tidal non-renewable WORD SELECTION: fossil non-renewable electricity uranium greenhouse tidal reliable run

Answer the questions on page 159. Energy Resources and Electricity Generation Notes questions from pages 150 to 159 Answer the questions on page 159. Verify that you can do all of the items listed in the end of chapter checklist on page 159.

Online Simulations