Alternatives to Nuclear Energy: Classifications and Technology

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Alternatives to Nuclear Energy Classifications
and Technology

• Erica Raheja
• 04/13/08

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Power Conversion Turbines

• Almost all electrical energy produced
• Driven by a fluid
• Most common steam
• Other wind or water
• Used to convert energy into electrical energy
  (attach to generator)
• Simplest shaft with blades attached
• Early examples windmills or waterwheels

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Alternative Energy Sources

• Fossil fuels coal, petroleum, natural gas
• Solar power
• Wind power
• Water power
• Hydro-electric
• Tidal
• Wave
• Geothermal power
• Biofuel

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Fossil Fuels

• Coal, petroleum, natural gas
• Found in the earths crust
• Non-renewable resource
• Burned to create steam which turns turbine

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Fossil Fuels cont.
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Pros of Fossil Fuels

• Large amounts of energy produced
• Relatively cheap
• Can build a plant almost anywhere
• Transportation of fuel relatively easy

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Cons of Fossil Fuels

• Pollution
• Burning fossil fuels produces carbon dioxide, a
  greenhouse gas
• Obtaining the fuel can have negative effects on
  the environment
• Acid rain
• Release of radioactive material
• Non-renewable resource

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Solar Power

• Three major categories
• Photovoltaic cells
• Solar power heating
• Solar furnaces
• Other research

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Solar Power cont.

• Photovoltaic (PV) cells
• Convert solar energy directly into electrical
• Photons from the light knock the electrons into
  an excited state, generating electricity
• Cells connected together in panels for more
  electricity

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Solar Power cont.

• Solar power heating
• Sun heats water in exposed glass panels
• Require less electrical power to heat
• Problem water in panels can freeze

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Solar Power cont.

• Solar furnaces or Concentrating Solar Power (CSP)
  system
• Concentrate sunlight into small beam by use of
  mirrors or lenses
• Can then use as heat source

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Solar Power cont.

• Trough system

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Solar Power cont.

• Power tower system

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Solar Power cont.

• Dish engine system

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Solar Power cont.

• More pictures

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Solar Power cont.

• Research/Experimental Technology
• Solar updraft tower
• A large greenhouse funnels heated air into a
  central tower which can turn turbines
• Solar pond
• A pool of salt water collects and stores solar
  energy

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Solar Power Pros

• It is free
• Can be used in remote locations
• Good for low-power usage
• Renewable resource

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Solar Power Cons

• Does not work at night
• Extremely expensive to build solar power stations
• Unreliable except in sunny climates

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Wind Power

• Wind blows in and turns propeller blades, turning
  a generator
• Pitch can be changed according to wind speed
• Made to turn and face wind

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Wind Power cont.

• Often build many wind towers together to create
  farm
• Need places where wind is reliable and strong

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Wind Power Pros

• Wind is free
• No waste products
• Land underneath potentially used for farming
  purposes
• Way of providing energy to remote locations
• Renewable resource

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Wind Power Cons

• Wind unpredictable, unreliable source of power
• Coastal land expensive
• Can kill birds
• Noise pollution

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Water Power

• Three major categories
• Hydro-electric power
• Tidal
• Wave

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Water Power cont.

• Hydro-electric power
• Running water has kinetic energy (converted from
  potential energy height)
• Generally dam built to trap water
• Water flows through dam, turning turbines as it
  passes by

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Water Power cont.

• Dam must be thicker at bottom to withstand
  pressure
• Expensive to build but water is free and produces
  cheap energy
• Evaporation from sun keeps lake filled with water

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Water Power cont.

• Hoover dam

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Water Power cont.

• Hydro-electric advantages
• Energy cheap after dam is built
• No waste or pollution produced
• Reliable source of power
• Water can be stored for peak usage
• Can increase to full power relatively fast
• Electricity can be produced constantly
• Renewable
• Disadvantages
• Expensive to build dams
• Changes to the environment
• Suitable sites can be difficult to find

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Water Power cont.

• Tidal power
• Dam built across a river estuary
• Ebb and flow of the tides either turns a turbine
  or pushes air through a pipe that turns a turbine

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Water Power cont.

• Largest tidal power station in the world Rance
  estuary in France
• Only can generate power when the tide is going in
  or out

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Water Power cont.

• Other option offshore turbines or tidal stream
  systems
• Similar to underwater wind farm
• Need locations in fast currents

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Water Power cont.

• Swanturbines design from University of Wales
  Swansea

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Water Power cont.

• Advantages
• Tidal power is essentially free, renewable, and
  clean once the original installation is made
• Produces electricity reliably - tides are
  predictable
• Not expensive to maintain
• Offshore turbines relatively inexpensive and
  low-impact on environment
• Disadvantages
• A barrage across an estuary is expensive
• Few sites (about 20 around the world)
• Only provides power for 10 hours

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Water Power cont.

• Wave power

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Water Power cont.

• Advantages
• Wave power is free, clean, and renewable
• Inexpensive to build and maintain
• Can produce a lot of energy
• Disadvantages
• Waves unpredictable - need suitable site
• Can be noisy
• Must be able to withstand all weather

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Geothermal Power

• Heat from the earth used for power
• Dry steam
• Steam from fractures used to drive turbine
• Flash
• Hot water rises and boils as it comes to the
  surface.
• Steam used to drive turbine
• Binary
• Hot water run through heat exchangers, boiling
  organic fluid used to drive turbine

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Geothermal Power cont.

• If there is not already water below ground, can
  pump water down
• Called Enhanced Geothermal System (EGS)

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Geothermal Power cont.

• Important resource in volcanically active areas
  Iceland, New Zealand
• Efficiency depends on the temperature of the
  water
• Can deplete a site

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Geothermal Power cont.

• The Nesjavellir Geothermal Power Plant in Iceland

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Geothermal Power Pros

• No pollution
• Power plants take up little room, giving it a low
  impact on the environment
• No fuel is needed
• Once built, energy almost free
• Work continuously
• Renewable resource

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Geothermal Power Cons

• Few places viable to build power stations
• Depletion of a site can occur
• Hazardous gas can rise to the surface
• Can lower land stability

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Biofuel

• Generally, biofuel is burned and used to heat
  steam
• Made of or derived from dead biological matter
• Exist in solid, liquid, and gaseous forms

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Biofuel cont.

• Solid biofuel wood, biogenic municipal solid
  waste, unused portions of field crops, animal
  wastes
• Can be burned for heat to warm homes or be used
  in external combustion engines
• Can convert wood and byproducts into liquid or
  gas via gasification

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Biofuel cont.

• Liquid biofuel bioalcohol (ethanol) or bio-oil
  (biodiesel or vegetable oil)
• Generally used in diesel engines
• No modifications needed for biodiesel
• Reduce emissions from fossil fuels
• Made from corn, sugarbeets, sugar cane, etc.

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Biofuel Pros

• Makes sense to use waste products when possible
• Fuel tends to be cheap
• Less demand on the earths resources
• Renewable resource

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Biofuel Cons

• Collecting in sufficient quantities can be
  difficult
• Burning does still produce greenhouse gases
• Some materials are not available all year round

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Biofuel cont.

• Biogas methane gas
• Produced from current waste streams like paper
  and sugar production and sewage
• Naturally ferment to create methane
• Mechanical biological treatment use anaerobic
  digesters to process biodegradable material
• Renewable natural gas upgraded to quality like
  natural gas

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World Primary Energy Production

• (Data from 2005)
• 36.8 petroleum
• 26.6 coal
• 22.9 dry natural gas
• 6.3 hydro power
• 6.0 nuclear power
• 0.9 other (geothermal, solar, wind, and biofuel)