Ch. 18 Renewable resources!!

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Ch. 18 Renewable resources!!
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Renewable energy energy from sources that are
constantly being formed

• Solar - sun
• Hydroelectric moving water
• Wind
• Biomass organic material
• Geothermal Earths heat
• Tidal - waves

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Solar Energy - energy from the sun

• Nuclear Fusion creates energy on the sun
• Only a fraction of this reached the Earth
• But, this is enough to power
• The wind (wind power)
• Plant growth (biomass)
• The water cycle (hydroelectricity)
• Nearly all renewable energy sources come from the
  sun!!!

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Passive Solar using the sun to heat something
directly (ex through windows)
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Active Solar collecting the suns energy to heat
buildings or water (ex solar cells or panels)

• Energy production from solar has doubled every 4
  years since 1985!!

http//videos.howstuffworks.com/science-channel/50
15-invention-nation-solar-panels-video.htm
http//solarsc.net/video/examples/how-solar-panels
-work.html
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Costs of Solar Energy

• All costs are up front costs, then savings follow
• Solar pool heater - 3000 - 4000
• Home solar water heater 1000 - 3500
• (includes installation)
• 1 kW power system 10,000 15,000
• 2 kW power system 16,000 - 20,000
• 5 kW power system 35,000 - 45,000
• (will power most homes)
• You can get federal tax credits up to 2000 and
  some state tax credits as well

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Wind Power

• Heat from the sun does not warm the earth evenly,
  causing the flow of air masses wind
• Fastest growing energy source
• Cost is decreasing

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Wind Farms

• Farmers can sell excess energy back to their
  local utility!!
• The windiest places on Earth could generate 10
  times more energy needed on earth!!
• Problem Transporting the energy from rural areas
  to where it is needed

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Biomass Power - any organic matter that is used
as an energy source

• Plants material, manure, methane, alcohol
• Major source of energy in developing countries!
• Problems
• cutting too many trees can cause severe
  environmental problems
• Burning can release large amounts of air pollution

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Methane a byproduct of decomposition

• Britains first Dung-Fired Power plant using the
  methane released from cow manure for energy
• US uses some energy from methane produced from
  landfills!

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Ethanol

• Produced from biomass!
• Benefits
• Renewable
• Less emissions
• Cons
• Takes lots of land
• Rise in produce prices

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Hydroelectricity energy produced by moving water

• 20 of the worlds electricity
• Leading Countries
• Canada
• US
• Brazil
• China
• Russia
• Norway

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Hydroelectric Energy

• Benefits
• Inexpensive to
• operate
• No air pollution
• Last longer than fossil fuel plants
• Flood control
• recreation

• Disadvantages
• Changes a rivers flow
• Reservoir floods the area
• Displaces people
• Reduces water flow
• Destroys salmon fisheries
• Dam failure
• Sedimentation

Today the era of large dam construction is most
likely over We are now using micro-hydropower
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Geothermal Energy energy from heat in the
earths crust

• US is the worlds largest producer of geothermal
  energy

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Costs of Geothermal Heat Pumps

• Heat pump 3,500 - 7,500
• Drilling/installation 10,000 - 25,000
• You can get federal tax credits up to 2000 and
  some state tax credits

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Alternative Energy energy sources that are
still in development

• How to get off the alternative list?
• Prove it is cost effective
• Environmental effects must be acceptable
• Current Alternative energy sources
• Tidal Power Ocean
• Ocean Thermal Energy Conversion (OTEC)
• Hydrogen

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Tidal Power

• Tides the movement of water caused by
  gravitational attractions between the sun, Earth
  and the moon.
• Currently used in
• France
• Russia
• Canada

Cost is high and not many places suitable enough
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Ocean Thermal Energy Conversion

• Warm ocean surface temperatures and cold
  subsurface temperatures are used to create
  electricity
• Surface temps boil water making steam.
• Cold subsurface water cools the steam
• Problems
• Pumping water costs too much
• Pumping cold water to the surface could cause
  problems

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Hydrogen??

• The most abundant element in the universe!
• Burning it produces water vapor not pollution
• Electricity is used to split water molecules to
  get hydrogen gas
• Challenges
• Takes a lot of energy to make
• Not safe to store

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Fuel Cells

• Combining Hydrogen and Oxygen produces
  electricity and its byproduct is water!
• No
  Emissions!!

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Energy Efficiency - of energy put into a system
that does useful work

• Ex a light bulbs light output not its heat
  energy
• More than 40 of energy produced in the US is
  wasted!!
• How to improve
• Public transport
• More efficient engines, i.e. fuel cells

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Hybrid Cars

• Less emissions
• Small efficient gas engine
• Electric motor
• Convert breaking energy into electricity
• Aerodynamic
• Lightweight material

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Cogeneration

• Using the same fuel source for two forms of
  energy
• Ex wasted heat from a furnace can be used to
  produce electricity

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Energy Conservation saving energy by reducing
use and waste

• How can we do this in our lives???

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