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Environmental Education

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Presentation on theme: "Environmental Education"— Presentation transcript:

1 Environmental Education
Lecture Notes : 2.7 Energy Conservation

2 Content What is “energy”? Types of “energy resources”
Non-renewable Renewable Energy conservation

3 What is “energy”? “Energy is used for doing work” Energy is everywhere
e.g. provides warmth, ability to move and think Energy is everywhere Usable free energy is limited e.g. fossil fuels, nuclear power and hydropower Need conservation of energy limited reserve overexploitation

4 Types of energy resources
Non-renewabe Cannot be replenished or renewable Fossil fuels Nuclear energy Renewable Can be replenished or renewed Geothermal Hydropower Ocean energy Solar energy Wind energy Biomass energy

5 Non-renewable: Fossil fuels[1]
Widely used Three kinds: coals: hard, black and rock-like substance oil/petroleum: thick liquid layer natural gas: found near oil underground, mixture of flammable gases, main component is methane (CH4) Made up of decomposed plant and animal many millions years ago decomposed and buried layer upon layer under high temperature and high pressure If they are used up, they will be gone!!! Need to save

6 Non-renewable: fossils fuels[2]
Grasshopper is used for extracting fossils fuels underground Sources:

7 Non-renewable: nuclear energy[1]
Energy is released when nuclear fission or nuclear fusion Nuclear fission: use a neutron to bump a large nuclei the nuclei splits into several smaller fragments and releases energy Nuclear fusion: release of energy when small nuclei are fused together Energy (from nuclear fission and fusion) boil water and turn generators for electricity

8 Non-renewable: nuclear energy[2]
Nuclear fission: A large nucleus splits into several small nuclei when bumped by a neutron and energy is released in this process. Nuclear fission Sources: Nuclear fusion: Several small nuclei fuse together and release energy. Nuclear fusion Sources:

9 Renewable: solar energy[1]
Solar energy can be converted to electricity in 2 ways: Solar thermal electricity Solar cell (Photovoltaic energy) use heat energy from the sun to boil water the stream formed then turn the turbine convert radiation energy to electricity directly

10 Renewable: solar energy[2]
The thermal energy of sun is converged by parabolic trough and used for boiling water. The steam is then used to push electricity generators. Sources: Parabolic trough (curve mirrors) In solar cells, solar radiation energy is converted to electricity directly. Electrons are stroked out under sunlight and attracted to the other pole, so electricity occurs. Sources: Solar cell e-




14 Renewable: wind energy[1]
Used for grinding grains, pumping water, and generating electricity pushed by wind Wind push the blade Turn the turbine Electricity generated by generators Sources: Produce electricity

15 Renewable: wind energy[2]
Group of wind turbine Increase electricity generation efficiency Sources:

16 Renewable: hydropower
“Hydro” -- water; “hydropower” -- power of water Used for grinding flour or corn and generation of electricity reservoir dam dam is built to stop water flow of a river reservoir is formed behind dam the water is controlled to pass via turbine at the dam generators is then driven to produce electricity Dam built for generating electricity Sources:

17 Renewable: ocean energy
Still in experimental stage, not common Three types: Waves energy Tidal energy Ocean thermal energy

18 Sources:
Ocean energy: waves When the air flows, turbine is turned and it would drive the generator. Electricity is produced. Sources:

19 Ocean energy: tidal and thermal
Tidal energy similar to hydropower plant dam traps the sea water when high tide when tide drops, water flow turns the turbine and drives the production of electricity of generator Ocean thermal energy application of the temperature difference of sea water

20 Renewable: Geothermal energy
“Geo” -- earth ; “thermal” -- heat The steam can be used to turn generator for electricity. Sources: Hot spring When the underground water is heated by magma, hot spring is formed. Sources: Cool Hot Very hot

21 Renewable: biomass energy
paper waste, trash, dead body, food waste, bark, sawdust and housing rubber, etc Production of fuel during biological processes e.g. fermentation targets products: e.g. hydrogen and ethanol they can be used for cars or generation of electricity

22 Energy conservation[1]
Most of the energy resources we use now is NON-RENEWABLE. If they are used up, they will be gone!!! We can: Save energy Develop new energy resources

23 Energy conservation[2]
Recycle and reuse Save water Turning off electrical appliances when not use Suitable management and application of electrical appliances e.g. lighting, water heater, washing machine and dry machine, refrigerator and air conditioner Save energy in cooking Save energy in cars

24 Discussion Compare nuclear power and fossil fuel.
Discuss the relationship between living quality and energy conservation. (Degradation of living quality?) Are there any environmental destruction of using renewable energy resources? (e.g.hydropower & geothermal) What kind of activities in our daily life are wasting energy resources? Does recycling really save energy?

25 Relevant Websites 1. Guangzhou Institute of Energy Conversion, the Chinese Academy Of Sciences 2. The Consumer Council—How to conserve energy? 3. Press release: Government and Hongkong Electric Sign Demand Side Management Agreement 4. Economic Services Bureau—Energy Supplies

26 5. Daily Information Bulletin -- Energy efficiency measures improve business competitiveness
6. Daily Information Bulletin-- Energy Efficiency Labels for Electric Clothes Dryers 7. Press release-- Energy Efficiency and Conservation Initiatives for 2000/01 8. The Environmental Protection Department – Saving energy in your home

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