Chapter 18 Renewable Energy Part 1: Hydropower, Solar, Wind

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Chapter 18Renewable Energy Part 1Hydropower,
Solar, Wind
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Renewable Energy

• We can use renewable energy to provide the same
  services as nonrenewable
• produce electricity
• heat/cool homes
• transportation
• power for industry

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• Review How do we make electricity from
  nonrenewable energy sources?
• Burn energy source ? to create steam
• turns turbine?
• turns electromagnet?
• generates electricity?
• carried by the wires to where needed

Steam can be generated by burning coal or natural
gas, or from nuclear reactions (all nonrenewable
energy sources)
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• How do we make electricity from renewable energy
  sources? Much the same way with hydropower
• Flowing water ?
• turns turbine?
• turns electromagnet?
• generates electricity?
• carried by the wires to where needed

The kinetic energy of water at higher elevations
is used to turn the turbine as it flows
downstream the water got there via the water
cycle clean, free energy
Dam
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Hydropower in the U.S.

• How it works
• http//www.youtube.com/watch?vcEL7yc8R42k

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• Percent of U.S. electricity that is generated by
  hydropower about 10

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Hydropower

• Advantages
• Renewable
• Domestic
• Clean, no emissions
• Dam provides other benefits (flood control,
  irrigation, recreation)

Disadvantages Dams have environmental
consequences change ecosystems cause
people to be displaced sediment
trapped risk of failure block migratory
fish Dams are very expensive
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Solar Energy

• Three ways to use it
• passive solar energy
• active solar energy
• photovoltaic cells make electricity using light

to heat homes, water
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Solar Heating
Passive system Absorbs stores heat from the
sun directly within a structure
Active system Collectors absorb solar energy, a
pump supplies part of a buildings heating or
water heating needs.
www.bio.miami.edu/beck/esc101/Chapter1415.ppt
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Photovoltaic Cells
Light strikes the PV cell, generates flow of
electrons
It takes a lot of surface area to generate enough
electricity
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Solar panels on homes provide electricity

• May be expensive to install (10s of 1000s of
  dollars)
• Some people dont like the looks of it

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Other uses of PV cells

• Street lights, calculators, road signs

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Large-scale energy production using solar power

• Concentrated Solar Power heat is collected to
  make steam and generate electricity
• One type of CSP Power towers mirrors focus
  sunlight on a heat collector which generates
  electricity

Power tower in Spain
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Large-scale energy production using solar power

• Another type of CSP Linear concentrators
  mirrors focus sunlight on a tube with liquid that
  heats up, goes to make steam and electricity
• http//www.nrel.gov/learning/re_basics.html

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• Solar farms use an array of many PV cells to
  generate electricity, this one at Nellis Air
  Force Base, CA, will provide 25 of the bases
  energy needs

The large space required can have an impact in
the fragile deserts where they are located
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Best places in the U.S. for use of solar energy
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Solar Energy

• Advantages
• Renewable
• Domestic
• Clean, no emissions
• Low environmental impact with certain solar
  systems (e.g., on roof)
• Adapted to small or large scale use

Disadvantages Doesnt work when sun is not
shining Doesnt work well in places with little
sunlight Can be expensive, unattractive Large
arrays of solar panels take a lot of space
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Wind Energy
People have used the power of wind for a long
time windmills grind grain, pump water
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Today we can use wind to generate electricity
only use it to meet 1 of worlds energy needs
www.bio.miami.edu/beck/esc101/Chapter1415.ppt
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• Video by National Renewable Energy Laboratory
• http//www.nrel.gov/learning/re_wind.html

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• Climbing a wind turbine
• http//www.google.com/imgres?imgurlhttp//www.alt
  ernative-energy-news.info/images/technical/wind-po
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  ws.info/technology/wind-power/usg__RmUKRizgMzJPC
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Disadvantage of wind farms visual impact
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Disadvantage of wind farms Wind turbines are
threats to wildlife (birds, bats)
http//www.youtube.com/watch?vRtgBWNKwBkEfeature
related
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Where is wind power feasible in the U.S. ?
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Wind farms

• Largest in world Roscoe, TX

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Wind farms

• Offshore wind farms in U.K.
• Thanet Wind Farm 300MW will supply 240,000
  homes with electricity

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Wind Energy
Disadvantages Doesnt work when wind isnt
blowing Doesnt work well in places with little
wind Can be unattractive and noisy Blades kill
wildlife Requires large area for wind
farms Offshore wind farms at risk from hurricane
damage

• Advantages
• Renewable
• Domestic
• Clean, no emissions
• Low environmental impact