Edexcel IGCSE Physics pages 150 to 159 EDEXCEL IGCSE / CERTIFICATE IN PHYSICS 4-4 Energy Resources and Electricity Generation Edexcel IGCSE Physics pages 150 to 159 June 17th 2012 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 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

Renewable and non-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 rotate a turbine (the blades) which turns an electrical generator. A wind farm Energy changes: kinetic to electrical

Renewable energy source No greenhouse gases No acid rain TRIPLE ONLY 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

Hydroelectric power Falling water is used to drive a turbine which rotates an electrical generator. Energy changes: gravitational potential to kinetic to electrical

Hydroelectric power station

Very limited locations Wildlife affected Expensive to build TRIPLE ONLY ADVANTAGES Renewable No greenhouse gases No acid rain No radioactive waste Short start up time DISADVANTAGES Very limited locations Wildlife affected Expensive to build The Hoover Dam near Las Vegas

Wave power Waves can be used to drive an electrical generator. Energy changes: kinetic to electrical

Can only be used in areas with suitable waves Prone to storm damage TRIPLE ONLY 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

Tidal power Moving water caused by the tides is used to drive a turbine directly which rotates an electrical generator. Energy changes: gravitational potential to kinetic to electrical Tidal power station at La Rance, Brittany

Tidal power station

Very limited locations Wildlife affected Expensive to build TRIPLE ONLY ADVANTAGES Renewable No greenhouse gases No acid rain No radioactive waste Short start up time DISADVANTAGES Very limited locations Wildlife affected Expensive to build Proposed Severn Estuary Tidal Power Scheme

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. Energy changes: thermal (heat) to kinetic to electrical

Very limited locations Expensive to build TRIPLE ONLY ADVANTAGES Renewable No greenhouse gases No acid rain No radioactive waste Short start up time DISADVANTAGES Very limited locations Expensive to build

Solar heating Heat energy from the Sun is focussed onto pipes containing water. The water boils producing steam. The steam is then used to drive turbines which turn electrical generators. Energy changes: thermal to kinetic to electrical

Sunshine needed and so best in desert regions TRIPLE ONLY ADVANTAGES Renewable No greenhouse gases No acid rain No radioactive waste DISADVANTAGES Sunshine needed and so best in desert regions Can only be used during the day A large amount of land is needed to produce a significant amount of energy

Solar cells Electricity produced directly from the Sun’s radiation. Energy changes: light to electrical

Unreliable in the UK! – sunshine is needed for solar cells TRIPLE ONLY ADVANTAGES Renewable No greenhouse gases No acid rain No radioactive waste Instant 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 a significant amount of energy

Fossil fuels Fossil fuels include coal, oil and natural gas. They have been formed in the ground from dead vegetation and tiny creatures by a process that has taken millions of years. When burnt the heat energy produced is used to produce steam. The steam is then used to drive turbines which turn electrical generators. Energy changes: thermal to kinetic to electrical

Coal-fired power station

Problems with fossil fuels TRIPLE ONLY 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

Concentrated energy source Reliable energy source TRIPLE ONLY ADVANTAGES Concentrated energy source Reliable energy source Can be built anywhere No radioactive waste DISADVANTAGES Non-renewable Produces greenhouse gases and contributes to global warming Produces acid rain

Nuclear power uranium fuel rods Nuclear power stations use a certain type of uranium to produce heat energy. This heat energy is used to produce steam. The steam is then used to drive turbines which turn electrical generators. Energy changes: nuclear to thermal to kinetic to electrical

A nuclear reactor

Problems with nuclear power stations TRIPLE ONLY 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

Concentrated energy source Reliable energy source TRIPLE ONLY ADVANTAGES Concentrated energy source Reliable energy source Can be built anywhere No greenhouse gases No acid rain DISADVANTAGES Non-renewable Radioactive waste Expensive to build Technology is related to that needed to make atomic bombs

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.

Choose appropriate words to fill in the gaps below: Most of our electricity is produced by thermal __________ 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. power fuels heat uranium water turbine rotates 90% WORD SELECTION: rotates fuels heat 90% uranium turbine water power

Online Simulations The Greenhouse Effect - PhET - Just how do greenhouse gases change the climate? Select the level of atmospheric greenhouse gases during an ice age, in the year 1750, today, or some time in the future and see how the Earth's temperature changes. Add clouds or panes of glass. BBC AQA GCSE Bitesize Revision: Generating electricity - Fossil Fuels Generating electricity - Nuclear Fuels Generating electricity - Wind Energy Generating electricity - Water Energy Generating electricity - Geothermal Energy Generating electricity - Solar Energy Generating electricity - Comparing sources BBC KS3 Bitesize Revision: Non-renewable energy Renewable resources Saving energy

TRIPLE ONLY Energy Resources and Electricity Generation Notes questions from pages 150 to 159 (a) Explain the difference between a renewable and a non-renewable energy source. (b) Give three examples of each. Briefly describe how the following energy sources can be used to produce electricity: (a) wind; (b) water; (c) geothermal; (d) solar; (e) fossil fuels and (f) nuclear. For each source listed in question 2 give two advantages and two disadvantages of their use in generating electricity. 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.

DOUBLE SCIENCE ONLY Energy Resources and Electricity Generation Notes questions from pages 150 to 159 (a) Explain the difference between a renewable and a non-renewable energy source. (b) Give three examples of each. Briefly describe how the following energy sources can be used to produce electricity: (a) wind; (b) water; (c) geothermal; (d) solar; (e) fossil fuels and (f) nuclear. Answer questions 1, 2 and 3 on page 159.