Environmental Education Lecture Notes : 2.7 Energy Conservation

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

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

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

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

Non-renewable: fossils fuels[2] Grasshopper is used for extracting fossils fuels underground Sources: http://www.energy.ca.gov/education

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

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: http://www.atomicarchive.com/Fission/Fission1.shtml Nuclear fusion: Several small nuclei fuse together and release energy. Nuclear fusion Sources: http://www.atomicarchive.com/Fusion/Fusion1.shtml

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

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: http://www.energy.ca.gov/education 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: http://www.energy.ca.gov/education Solar cell e-

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: http://www.energy.ca.gov/education Produce electricity

Renewable: wind energy[2] Group of wind turbine Increase electricity generation efficiency Sources: http://www.energy.ca.gov/education

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: http://www.energy.ca.gov/education

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

Sources: http://www.energy.ca.gov/education Ocean energy: waves When the air flows, turbine is turned and it would drive the generator. Electricity is produced. Sources: http://www.energy.ca.gov/education

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

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

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

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

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

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?

Relevant Websites 1. Guangzhou Institute of Energy Conversion, the Chinese Academy Of Sciences http://www.giec.ac.cn/ 2. The Consumer Council—How to conserve energy? http://www.consumer.org.hk/pamphlet/chinese/energy.htm 3. Press release: Government and Hongkong Electric Sign Demand Side Management Agreement http://www.info.gov.hk/esb/refer/press/te971105.htm 4. Economic Services Bureau—Energy Supplies http://www.info.gov.hk/esb/chinese/respone/4.htm

5. Daily Information Bulletin -- Energy efficiency measures improve business competitiveness http://www.info.gov.hk/gia/general/199810/29/1029106.htm 6. Daily Information Bulletin-- Energy Efficiency Labels for Electric Clothes Dryers http://www.info.gov.hk/gia/general/199912/27/1224103.htm 7. Press release-- Energy Efficiency and Conservation Initiatives for 2000/01 http://www.info.gov.hk/efb/chinese/press/10022000.html 8. The Environmental Protection Department – Saving energy in your home http://www.info.gov.hk/epd/chinese/pub/tips/saveng.htm