Ch 4 2 Alternate Energy Sources by wuzhengqin


									                    Warm Up 10/13
1. Which of the following lists presents forms of coal in the
   correct order from the first stage of development to the
   last stage of development?
   a. peat, lignite, anthracite, bituminous
   b. anthracite, bituminous, lignite, peat
   c. peat, lignite, bituminous, anthracite
   d. bituminous, anthracite, peat, lignite
2. Vein deposits are usually produced by ____.
   a. hydrothermal solutions            c. weathering
   b. cementation and compaction d. density sorting
3. Which of the following is an example of a nonrenewable
   a. cotton        c. uranium
   b. cattle        d. trees
Answers: 1) c. 2) a. 3) c.
Alternate Energy Sources

    Chapter 4, Section 2
                  Solar Energy
• Every second, the total energy Earth receives from
  the sun amounts to more than 10,000 times the
  total energy used by all human societies in a day
• Solar energy technologies use the sun’s rays to
  supply heat or electricity
• Solar energy has two advantages: The “fuel” is
  free, and it’s non-polluting
• There are a few drawbacks to solar energy: the
  necessary equipment and installation is not free,
  and a supplemental heating unit is needed for the
  times when the sun is not out
• Research is currently underway to improve the
  technologies for collecting sunlight
      Solar Energy

Solar One outside Barstow, California
             Concept Check

• What are the two main advantages to using
  solar energy?
• The fuel is free and it is non-polluting!
                Nuclear Energy
• Nuclear power meets about 7% of the energy
  demand of the U.S.
• The fuel for nuclear plants comes from radioactive
  materials that release energy through nuclear fission
• In nuclear fission, the nuclei of heavy atoms such as
  uranium-235 are bombarded with neutrons; the
  uranium nuclei then split into smaller nuclei and
  emit neutrons and heat energy
• The neutrons that are emitted then bombard the
  nuclei of adjacent uranium atoms, producing a chain
• The heat energy drives steam turbines that turn
  electrical generators
                    Nuclear Energy

                              Fuel Pool

San Onofre Nuclear Plant,
              Concept Check

• What is nuclear fission?
• The splitting of an unstable nucleus of an
  atom into smaller parts, releasing large
  amounts of energy
                 Wind Energy
• Wind is not a new energy source, we have
  been using it for centuries to power sailing
  ships and windmills for grinding grain
• In the year 2000, wind supplied a little less
  than one percent of California’s electricity
• Some experts estimate that in the next 50 to
  60 years, wind power could meet between 5
  to 10 percent of the country’s demand for
• The need for technical advances, noise
  pollution, and the cost of large tracts of land
  in populated areas are obstacles to
        Wind Energy

Wind Turbines outside Palm Springs, California
             Hydroelectric Power
• Like wind, moving water has been an energy source
  for centuries
• Hydroelectric Power – the power generated by
  falling water
• In the U.S., hydroelectric power plants produce
  about 5 percent of the country’s electricity
• The water held in a reservoir behind a dam is a form
  of stored energy that can be released through the
  dam to produce electric power
• Eventually rivers deposit sediment in the reservoir to
  a point where the dam can no longer produce
  electricity; this process takes approximately 50 to
  300 years, depending on the amount of material the
  river carries
      Hydroelectric Power

Glen Canyon Dam and Lake Powell, Arizona and Utah Border
             Geothermal Energy
• Geothermal Energy – the energy that can be
  extracted from Earth’s internal heat, for example,
  natural steam used for power generation
• Hot water is used directly for heating and to turn
  turbines to generate electric power
• The reservoirs of steam and hot water occur where
  subsurface temperatures are high due to relatively
  recent volcanic activity
• Geothermal power is clean but not inexhaustible,
  with the steam and hot water from individual wells
  usually lasting no more than 10 to 15 years
  Geothermal Energy

The Geysers north of Santa Rosa, California
               Concept Check

• In what two ways is geothermal energy
• Directly for heating and to turn turbines to
  generate electricity
                 Tidal Power
• Tidal power is harnessed by constructing a
  dam across the mouth of a bay or an estuary
  in coastal areas with a large tidal range
• The strong in-an-out flow that results drives
  turbines and electric generators
• Tidal power development isn’t economical if
  the tidal range is less than eight meters or if
  a narrow, enclosed bay isn’t available
• Tides will never produce a high portion of the
  world’s energy needs, but it is an important
  source at certain sites
Tidal Power

• Read Ch. 4, Sect. 2 (pg. 102-107)
• Do Section 4.2 Assessment #1-6 (pg. 107)

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