Geologic Resources: Part 2

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Geologic Resources Part 2
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Alternative Energy Types

• Fossil Fuels
• Limited supply
• Alternative energyany alternative to fossil
  fuels
• Nuclear (non-renewable)
• Wind, solar, geothermal, hydroelectric

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Nuclear Fuels

• Nuclear fuels are any material that can be used
  to create nuclear energy
• Non-renewable
• Most common nuclear fuels
• Uranium-235
• Plutonium-239

Enriched Uranium Billet
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A note on Uranium

• Naturally occurring uranium
• Mix of isotopes
• U-238, U-235, U-233
• Only .7 U-235
• Need 3 to be used as fuel
• Enrichmentseparation of the isotopes to get more
  U-235

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Nuclear Fission and Energy Production

• Nuclear fission
• the splitting of an atom
• U-235 commonly used
• U-235 nucleus is bombarded by neutrons
• Chain reaction

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If left unchecked
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If checked
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How to Control a Nuclear Reaction

• Fuel pellets are contained in fuel rods
• Fuel rods are bundled with neutron-absorbing
  control rods
• Control rods inserted into reactor to slow
  reaction--withdrawn to speed reaction

Uranium fuel pellets and fuel rod. Each pellet
contains as much energy as one ton of coal
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NPP Layout
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Nuclear Power Pros

• Low fuel consumption
• 3 kg/day vs 9000 tons/day for coal
• Uranium fuel is more abundant than fossil fuels
• If the world were to use nothing but nuclear
  power, reserves would last 400 years vs 35 yrs
  for fossil fuels
• Low air pollution
• Compared to fossil fuels
• Lowers dependence on foreign fuels

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Nuclear Power Cons

• 20 tons/yr waste
• Every step of production
• Waste is radioactive
• 10k years or more to decay to safe levels of
  radioactivity
• Minor mistakes can create serious public health
  hazards

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Chernobyl

• April 1986
• Did not create a nuclear explosion
• Chain reaction got out of control-two explosions
• Exposed reactor to airgraphite moderators burned
• Plume of radioactive fallout into airwind
  carried it over western soviet union, Europe, and
  eastern N. AM

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Renewable Alternatives
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Renewable Energy

• Resources that are replenished as they are
  usedrenewable
• The Big Four
• Solar
• Wind
• Geothermal
• Hydroelectric

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Solar Energy

• lt1 of global energy
• Passive solar collection
• South facing windows
• Active solar collection
• Moving parts to
• Distribute heat generated
• Solar arrays

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Pros and Cons of Solar Energy

• Pros
• No pollution
• Quiet
• Good for remote areas
• Putting up solar panels cheaper than laying out
  cables for traditional transmission of
  electricity
• Utilize existing space
• Ex. Rooftops

• Cons
• High start up cost
• diurnal
• Weather/pollution effects
• Current cell models are very inefficient

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Wind Energy

• Only 1.5 of global energysteadily rising
• Wind turbines use kinetic energy (energy of
  motion) from wind to generate electricity

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Pros and Cons of Wind Energy

• Pros
• No pollution
• Versatile
• Can generate electricity for single homes or
  large numbers of homes
• Do not consume anything aside from the materials
  used to create them

• Cons
• Unsightly
• Noisy
• Can be easily damaged in thunderstorms
• Blades can hit birds that try to fly between them
• Interference with migratory routes

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Geothermal Energy

• lt1 of global energy
• Energy extracted from the earths own
  subterranean heat
• Natural, hot ground water can be used to generate
  electricity or to directly heat homes
• Can also pump cool, surface water into earth to
  heat it

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Pros and Cons of GE

• Pros
• Cheap (after initial costs)
• No pollution
• Can use its own electricity to power pumpslittle
  need for exterior power sources
• Reliable

• Cons
• High initial expense
• Need to drill wells, install piping
• Requires lots of space
• Aesthetics
• Geothermal power plants are uglyplain and simple
• Expensive to dig deepnear surface magma sources
  are somewhat rare except in certain places

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Hydroelectric Energy

• 19 of worlds energy
• Dammed water is used to spin giant turbines
  electricity is generated

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Pros and Cons of HE

• Pros
• Low pollution generation
• Reliable
• Flood control
• Recreation areas
• Boating, fishing

• Cons
• Damming a river destroys local eco-systems
• Fish migration
• Flooding of river valleys
• Disruption of river seasonal cycles
• Material transported by river is stopped by dam
• Expensive to build
• A dam breach can flood downstream areas