renewable and non-renewable energy sources hany el-gezawy 2012-2013

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Renewable and non-renewable energy sources Hany El-Gezawy 2012-2013 Slide 2 Slide 3 Slide 4 Slide 5 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. Hany El-Gezawy 2012-2013 Slide 6 Hydroelectric power Falling water is used to drive a turbine which rotates an electrical generator. Energy changes: gravitational potential to kinetic to electrical Hany El-Gezawy 2012-2013 Slide 7 Hydroelectric power station Hany El-Gezawy 2012-2013 Slide 8 ADVANTAGES Renewable No greenhouse gases No acid rain No radioactive waste Short start up time DISADVANTAGES Very limited locations Wildlife affected Expensive to build TRIPLE ONLY The Hoover Dam near Las Vegas Hany El-Gezawy 2012-2013 Slide 9 Wave power Waves can be used to drive an electrical generator. Energy changes: kinetic to electrical Hany El-Gezawy 2012-2013 Slide 10 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 TRIPLE ONLY Hany El-Gezawy 2012-2013 Slide 11 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 Hany El-Gezawy 2012-2013 Slide 12 Tidal power station Hany El-Gezawy 2012-2013 Slide 13 ADVANTAGES Renewable No greenhouse gases No acid rain No radioactive waste Short start up time DISADVANTAGES Very limited locations Wildlife affected Expensive to build TRIPLE ONLY Proposed Severn Estuary Tidal Power Scheme Hany El-Gezawy 2012-2013 Slide 14 Wind power Wind is used to rotate a turbine (the blades) which turns an electrical generator. A wind farm Energy changes: kinetic to electrical Hany El-Gezawy 2012-2013 Slide 15 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 TRIPLE ONLY Hany El-Gezawy 2012-2013 Slide 16 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 Hany El-Gezawy 2012-2013 Slide 17 ADVANTAGES Renewable No greenhouse gases No acid rain No radioactive waste Short start up time DISADVANTAGES Very limited locations Expensive to build TRIPLE ONLY Hany El-Gezawy 2012-2013 Slide 18 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 Hany El-Gezawy 2012-2013 Slide 19 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 TRIPLE ONLY Hany El-Gezawy 2012-2013 Slide 20 Solar cells Electricity produced directly from the Suns radiation. Energy changes: light to electrical Hany El-Gezawy 2012-2013 Slide 21 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 TRIPLE ONLY Hany El-Gezawy 2012-2013 Slide 22 Nuclear power 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 uranium fuel rods Hany El-Gezawy 2012-2013 Slide 23 A nuclear reactor Hany El-Gezawy 2012-2013 Slide 24 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 TRIPLE ONLY Hany El-Gezawy 2012-2013 Slide 25 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 TRIPLE ONLY Hany El-Gezawy 2012-2013 Slide 26 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 Hany El-Gezawy 2012-2013 Slide 27 Coal-fired power station Hany El-Gezawy 2012-2013 Slide 28 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 TRIPLE ONLY Hany El-Gezawy 2012-2013 Slide 29 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 TRIPLE ONLY Hany El-Gezawy 2012-2013 Slide 30 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. Hany El-Gezawy 2012-2013