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ENERGY & THE ENVIRONMENT

ENERGY & THE ENVIRONMENT. Unit Review. Contents. Fossil Fuels. Alternative Energy. Electricity. Transportation. Environment. Creating Electricity. Flow of electrons = electricity Generator spins copper coil inside magnets knocking loose electrons.

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ENERGY & THE ENVIRONMENT

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  1. ENERGY & THE ENVIRONMENT Unit Review

  2. Contents Fossil Fuels Alternative Energy Electricity Transportation Environment

  3. Creating Electricity • Flow of electrons = electricity • Generatorspins copper coil inside magnets knocking loose electrons A loop of wire spinning through a magnetic field will create an alternating current. Note: current will flow only if the circuit connected to the generator is complete.

  4. Creating Electricity: Methods • Heat (makes steam and drive turbines): fossil fuel combustion, solar heat, nuclear reaction

  5. Creating Electricity: Methods • Mechanical: hydroelectricity, wind turbines

  6. Creating Electricity: Methods • Solar light: photovoltaic cells (PVCs)

  7. Fossil fuels • Highly concentrated carbon sources • Plants and animals decayed millions of years ago • Reliance is dangerous • Running out of resources • Causes high levels of pollution • Often from unstable or unfriendly governments Coal Oil Natural Gas

  8. World coal reserves Coal • Dirty, about 35% efficiency • Huge formations in U.S., Russia, China • Most electricity in China from coal, polluting U.S.

  9. HARDEST SOFTEST Underground mine Types of Coal • Anthracite(in Appalachia) • Bituminous (large reserves in IL, WY) • Sub-bituminous • Lignite • Peat Strip mining

  10. World oil reserves Oil • Formed from algae buried in sediment and cooked • U.S. supply sources: Canada, Mexico, Saudi Arabia, Venezuela

  11. Non-fuel petroleum products • Plastics • Fertilizer • Asphalt • Cosmetics • Medicine • Clothing (polyester, nylon, polypropylene)

  12. World natural gas reserves Natural Gas • Forms above oil bearing rock • Promoted as substitute for other fossil fuels • Emits about 50% less carbon than oil or coal

  13. Uses of Natural Gas • Power plants • Domestic • Cooking • Heating • Fertilizer • Transportation • CNG, LNG • Making hydrogen fuel

  14. Non-polluting power sources Solar Wind Nuclear Water Geothermal

  15. Nuclear Energy • Earliest use = weapon • Nuclear reaction creates heat

  16. FUSION Nuclear Reactions • Fission = splitting of atoms; primary method for nuclear energy use • Fusion = joining atomic nuclei to make heavier atoms, releases excess matter as energy

  17. Nuclear Fuels • Uranium: mined & refined • Plutonium: produced from uranium • MOX (mixed oxide fuel): recycled nuclear waste

  18. Advantages of Nuclear Energy • Long-lasting, more predictable • Clean and efficient, environmentally friendly • Cost effective, a lot of energy is produced quickly

  19. Disadvantages of Nuclear Energy • Operational issues • Plants are more expensive than solar or wind farms • Expensive to decommission • Radiation containment, waste disposal • Potential problems • Shortens life, causes cancer, damages genetics • Plutonium (optional fuel) can be used in weapons • Nuclear accidents can be catastrophic

  20. Solar Energy • Types • Light:Photovoltaic cells (PVC) convert light to electricity • Heat: Solar ponds, solar collectors (mirrors) collect heat • Best place • Lots of sunshine, open environment, warm climate (ponds) • Good example: greenhouse • Uses: heating, cooling, light, electricity

  21. Advantages of Solar Energy • No harmful effects to humans/environment • Can be used in space Installing major solar arrays in the marked locations would supply all the world’s energy needs.

  22. Disadvantages of Solar Energy • Not all parts of the world are reliably sunny • PVCs are not very powerful nor efficient • Limited infrastructure

  23. Using Solar Energy • Passive • Shine on walls for radiant heat • Natural light • Active • Store PVC energy in batteries • Heat water • Pump to other areas

  24. Preparing blades for installation Wind Energy • Earlyuses: grinding corn, pumping well water

  25. Wind • Advantages: free, unlimited source • Disadvantages • Need constant winds between 10 and 30 mph. • Danger to birds • Wind farms take a lot space (no shadowing) • Noisy

  26. waves dam pumpedstorage tidal exchange barrage Hydroelectric • Potential energy converted to kinetic energy Grand Coulee Dam, WA

  27. Advantages of Hydroelectricity • Low operating cost (fuel) • Flood control • No combustion pollution • Gathers water for tourism & agriculture

  28. Disadvantages of Hydroelectricity • Needs lots of moving water • Failure risk • Lack of public support • Fish need ladders • Decomposing vegetation creates greenhouse gases (new dams)

  29. Geothermal • From Earth’s mantle • Used for hot water, heating, electricity • Near surface in limited areas • Can be depleted

  30. Environment Greenhouse Gases Smog Pollution Effects Global Warming World Efforts Greenhouse Effect

  31. New York City Smog • Smog • Partially burned fuels (smoke) + atmospheric moisture (fog) • Photochemical smog: sunlight interacting with air pollutants. • Industrial smog: burning hydrocarbons

  32. Pollution Effects • Damages humans • Burning lungs, coughing • Respiratory irritation, asthma • Headaches • Damages environment • Stunts plants • Acid rain

  33. Greenhouse Gases • Primary • Carbon dioxide (CO2) • Methane (CH4) • Nitrogen oxide (NO) • Secondary • Water vapor • Ozone • Chlorofluorocarbons • Others

  34. Greenhouse Effect • Ozone layer lets sun’s heat in, keeps radiation out • Natural occurrence, accelerated by human activity • Greenhouse gases harm ozone layer

  35. Global Warming • When Greenhouse Effect keeps in too much heat • Gases thicken stratosphere, damage ozone layer • Not enough heat can escape • Earth gradually warms • Only 2° global increase will: • Melt ice caps • Flood low lying areas • Cause deforestation • Decrease arable land • Reduction • Drive less; use public transportation, walk, carpool • Reduce use of gasoline powered machines, pesticides, chemical solvents, other polluting technology

  36. World Efforts • U.N. Framework Convention on Climate Change • Kyoto Protocol (1997) • Global pollution reduction plan • US didn’t ratify • U.N. Intergovernmental Panel on Climate Change • Paris 2007 • Scientists reported that Global Warming is being accelerated by human activity • Governments must now take action • Durban (S. Africa) 2012 • Sea levels rising faster than predicted • Kyoto Protocol not re-ratified by all countries

  37. Alternative Transportation Fuels Electricity Natural Gas Hydrogen Biofuels

  38. Alternative Fuel Vehicles • Hybrid:Uses gasoline and electricity from batteries. • Electric plug-ins • Hydrogen • Air car

  39. Coal-fired plant Electricity for Transportation • Plug-in to outlets may stress power grid • Lacking infrastructure for recharging • Most methods of electricity generation still pollute

  40. Natural Gas for Transportation • CNG cleaner than gasoline • As powerful as gasoline if compressed • Not as powerful as diesel • LNG used in airplanes, jets • Used to make hydrogen

  41. Hydrogen for Transportation • Made from water with electricity or directly from fossil fuels • Colorless, odorless, non-metallic, tasteless, highly flammable • Advantages • does not pollute • when burned, creates only water • Disadvantages • Difficult to produce in quantity • Difficult to distribute • Best method burns fossil fuels • Highly flammable

  42. switchgrass Biomass Sources • Plant, wood and animal waste (agricultural waste, landfill gases) • Organic oils • Forest byproducts • Certain crops • Corn • Sugar cane • Soybeans • Switchgrass

  43. 2000 2003 2008 2005 Creating Biomass • Deforestation: cutting down rainforest for arable land • Fertilizer • Needed to increase production • Run-off pollutes rivers • Food vs. Fuel • Prices may be better for fuel use than food • Not enough arable land to support both uses • Natural crop failures increase problem

  44. Biofuels for Transportation Ethanol Methanol Biodiesel

  45. Ethanol • Primary biofuel • Plant alcohol from corn, sugar cane, soybeans, agricultural waste • Mixed w/gasoline 10 – 85% (E85) • 1:1 CO2 exchange • More expensive to make than gasoline • Uses fossil fuels in production

  46. Methanol • Alcohol made from animal waste • Toxic to humans if ingested • Can be converted to transportation fuel • Required for supercharged engines in monster trucks, dragsters

  47. Biodiesel • Advantages • Reduces car emissions, smoke, noxious fumes • Safe to store and handle (non-toxic, biodegradable, non-flammable) • Diesel engines are more efficient than gasoline engines • Disadvantages • Biodiesel used only in diesel engines • Does not replace gasoline.

  48. toaster house wiring power lines transformer Solar light (PVC) turbine generator power plant compressed steam heat water • Combustion • Coal • Oil • Natural gas • Biofuels • efficient • non-renewable • pollution Water = hydroelectricity • renewable • limited Wind = wind turbines Nuclear Solar heat

  49. Fossil Fuel Formation

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