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science form 1 chapter 6 sources of energy


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science form 1 chapter 6 sources of energy

  1. 1. Nursyazwani binti Shawal
  2. 2. SOURCES OF ENERGY Firewood Fossils fuel Hydroelectric energy Wind energy Wave energyBiomass energy Solar energy Geothermal energy Energy from radioactive substances Nursyazwani binti Shawal
  3. 3. Hydroelectricity – electricity generated using water Hydroelectric power – generated by forcing moving water to produce electricity. Water flowing from a dam has potential energy. This energy can be used to rotate turbines and dynamos to generate electric energy at a hydroelectric power station. Water falling from a great height has a lot of potential energy that can be used to drive turbines that generate electricity. Nursyazwani binti Shawal
  4. 4. The water turbines turn the generators which then change the kinetic energy of the moving water into electrical energy. The water that flows down from the dam contains kinetic energy that turns the water turbines. Potential energy is found in water; in a dam, located at a high position. Nursyazwani binti Shawal
  5. 5. Wind – moving air that contains kinetic energy. Windmills – for pumping water /grinding grains. - used for centuries to convert wind energy into chemical energy; to drive machine. Wind turbine – uses energy from the wind to generate electricity. Wind has kinetic energy that is used to rotate windmills for the purpose of a) Grinding wheat b) Pounding maize c) Pumping water for the use of animals and irrigation. Nursyazwani binti Shawal
  6. 6. The sea rises and falls twice a day. Tide – the rising and falling of the sea level Wave have kinetic energy and potential energy used to rotate turbines of dynamos in wave-generated power stations. Not widely used because the electric energy produced is not constant but follows the condition of the sea. The difference in height of the water at high tide and low tide is used in a tidal power station to generate electricity. As the tide comes in, water flows through turbines to generate electricity . When the tide goes out, water flows in opposite direction. Nursyazwani binti Shawal
  7. 7. Used to describe energy that comes from biological materials such as animal faeces, plants and household wastes. Decaying organic substances produce methane gas. Ethanol is obtained from fermented plant materials. Also can be obtained by burning rubbish; producing heat energy. Used as fuel for producing heat, working machines and moving vehicles. Nursyazwani binti Shawal
  8. 8. Energy derived from the Sun. Heat and light are 2 forms of solar energy. Solar cells absorb light energy from the Sun directly, change it into electrical energy. Solar cells are used to provide electricity for: a) Calculators b) Satellites c) Watches d) Certain vehicles Solar heater – change energy from the Sun into heat energy which then used for: a) Heating up water b) Cooking purposes Nursyazwani binti Shawal
  9. 9. Obtained from trunks, branches and twigs of trees. Most firewood is used in rural area as fuel for cooking. Produces a lot of soot that pollutes the environment. Nursyazwani binti Shawal
  10. 10. Combustible materials – they burns easily to release heat and light energy. Supply almost 90% of fuel energy today – most widely used fuel. Examples of fossil fuels: a) Oils (petroleum / crude oil) b) Natural gas c) Coal Most fossil fuels used in power stations to generate electricity. Nursyazwani binti Shawal
  11. 11. Comes from the very hot interior of the Earth in the form of heat energy. Most geothermal areas are near a) volcanos b) hot spring c) geysers Geothermal energy can be a) A tourist attraction b) A direct source of heating c) Used as an instant steam-generating facility to spin a turbine. Water under the Earth is heated and then pumped out to a) Heat buildings b) generate electricity Nursyazwani binti Shawal
  12. 12. The steam is channeled into pipes to: - Heat buildings - Rotate turbines of dynamos in geothermal power plants Water that is trapped in the ground is very hot and is in the form of highly pressurized steam. Nursyazwani binti Shawal The uses of geothermal energy
  13. 13. Radioactive substances like uranium and plutonium can be used to produce nuclear energy. Nuclear reactions generate lots of heat energy that can be used to generate electricity. Splitting of atoms in radioactive substances release heat that can be used to produce steam. Steam turns turbines and dynamos to generate electricity. Nursyazwani binti Shawal
  14. 14. Energy from radioactive substances can be used to generate electric energy for a) Ships b) Submarines c) Satellites d) Meteorological stations e) Lighthouses Radioactive wastes are dangerous because they give out radioactive radiation that is hazardous. Nursyazwani binti Shawal
  15. 15. Sources of energy in the world can be classified into 2 groups: Renewable energy sources – those that can be replenished (ditambah) or renewed when they have been used OR energy sources which cannot be depleted despite continuous use. Non-renewable energy sources – those that cannot be replenished or renewed and will eventually be used up and exhausted OR energy sources which will be depleted one day and we will not be able to replace them. Nursyazwani binti Shawal
  16. 16. Sources of Energy Renewable Non-renewable •Hydroelectric (moving water) •Fossil fuels (coal, petroleum, natural gas) – not last long •Wind energy •Radioactive substances (nuclear energy) – last a long time •Wave energy •Biomass energy •Solar energy •Firewood •Geothermal energy Nursyazwani binti Shawal
  17. 17. Nursyazwani binti Shawal Hydroelectric energy Advantages:  The electricity produced is cheap and does not pollute the environment. Disadvantages:  Dams and power stations are expensive to build.  Only suitable in mountains areas with good rainfall.  Large dams destroy habitats.
  18. 18. Nursyazwani binti Shawal Wind energy Advantages:  Does not pollute the environment.  Free Disadvantages:  Wind turbines stop working if there is no wind.  Speed and direction of wind unrelieable  Many wind turbines are needed to generate the same amount of energy as one fossil fuel power station.
  19. 19. Nursyazwani binti Shawal Wave energy / Tidal energy Advantages:  Does not pollute the environment.  Occur daily and always present Disadvantages:  Only generates electricity twice a day during high (pasang) and ebb (surut) tides.  Waves vary in strength  Expensive to build the power station
  20. 20. Nursyazwani binti Shawal Biomass energy Advantages:  Reduce environmental burdens / waste organic matter  Cheap sources of energy Disadvantages:  Releases gases such as carbon dioxide and sulphur dioxide that pollute the environment.  Requires a large amount of biomass  Takes up a large area
  21. 21. Nursyazwani binti Shawal Solar energy Advantages:  Can be produced continuously.  Does not pollute the environment. Disadvantages:  Cannot work at night or only operates during the day while the Sun is shining.  Expensive to install solar panels  Depends on whether conditions
  22. 22. Nursyazwani binti Shawal Firewood Advantages:  Can be used in areas that lack energy supply for cooking. Disadvantages:  Releases soot which pollutes the environment.
  23. 23. Nursyazwani binti Shawal Geothermal energy Advantages:  Does not pollute the environment.  Plentiful supply of heat Disadvantages:  Only available where hot water is located close to the Earth’s surface.  Harmful substances present in the steam, e.g. sulphur dioxide  Expensive to build a power station
  24. 24. Nursyazwani binti Shawal Fossil fuel Advantages:  High energy value / release a lot of energy  Easy to burn Disadvantages:  Produces gases that are poisonous (like sulphur dioxide) and form acid rain.  Pollute the environment  Coal produces a lot of soot
  25. 25. Nursyazwani binti Shawal Radioactive substance Advantages:  Very high energy value / supplies plenty of heat energy Disadvantages:  Gives off harmful radiation that can cause cancer.  Very expensive to build nuclear power stations.  Danger of accidents  Suitable radioactive elements not easily obtained
  26. 26. Sources of Energy Pollute the environment Do not pollute the environment •Fossil fuels (coal, petroleum, natural gases) •Hydroelectric energy •Radioactive substances (nuclear energy) •Wind energy •Biomass •Wave energy •Firewood •Solar energy •Geothermal energy Nursyazwani binti Shawal
  27. 27. Solar cells Solar cells absorb sunlight and convert it into electrical energy to operate calculators Solar heaters Solar panels are placed on the roofs of houses for absorbing heat from the sun. the heat is used for heating water in hot water systems Solar cookers In hot countries, solar cookers concentrate the Sun’s rays to obtain heat for cooking Solar power stations Solar panels are used to absorb the Sun’s heat for boiling water. The steam produced is used for turning turbines which drive generators for producing electricity Nursyazwani binti Shawal
  28. 28. Telephone in rural areas Some rural areas are installed with telephones which are operated by solar cells Satellites Solar panels on satellites absorb sunlight and change it into electrical energy for operating the satellites Photosynthesis Green plants absorb light energy from the sun and use it to make food by photosynthesis. In this way, solar light energy is converted into chemical energy Nursyazwani binti Shawal
  29. 29. To save non-renewable sources of energy such as fossil fuels (oil, gas, coal) from depletion as the supply is limited; but widely used all over the world. To reduce the amount of money spent on electricity, gasoline (minyak petrol) and other forms of energy. To protect our high standard of living which is due (in part) to our abundant energy sources. To reduce the ‘side effects’ of energy use: pollution, damage to animal habitats and ruined landscapes. Nursyazwani binti Shawal
  30. 30. More efficient equipment must be invented so that energy can be used more economically. Develop the use of renewable energy sources to replace non-renewable energy sources. Use non-renewable energy sources in an economical, efficient and smart way. New fuels such as diesel and palm oil, and other renewable energy sources like hydroelectric energy, biomass energy, wind energy and wave energy should be widely used as alternative energies. Nursyazwani binti Shawal
  31. 31. Since the Earth has limited amounts of non-renewable energy sources like fossil fuels, they must be conserved in order to avoid:  Future energy crisis due to shortages or overuse of fossil fuels.  A growing exploitation of natural resources.  Atmospheric contamination that causes global warming and climatic changes, acid rain and smog. The resulting impact damages water sources e.g. groundwater, soil, crops, wildlife and wildlife habitats, building materials and human health. Nursyazwani binti Shawal
  32. 32. Recycle material Develop more efficient engines that use less energy to operate. Put emphasis (penegasan/penekanan) on the use of renewable energy sources such as solar energy. Nursyazwani binti Shawal